1 .\"@ nail.1 - S-nail(1) reference manual.
3 .\" Copyright (c) 2000-2008 Gunnar Ritter, Freiburg i. Br., Germany.
4 .\" Copyright (c) 2012 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
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34 .\"@ S-nail(1): v14.9.0-pre3 / 2016-12-31
36 .ds VV \\%v14.9.0-pre3
46 .\" If not ~/.mailrc, it breaks POSIX compatibility. And adjust main.c.
51 .ds OU [no v15-compat]
52 .ds ID [v15 behaviour may differ]
53 .ds NQ [Only new quoting rules]
64 .Nd send and receive Internet mail
70 .\" Keep in SYNC: ./nail.1:"SYNOPSIS, main()
78 .Op Fl a Ar attachment
81 .Op Fl M Ar type | Fl m Ar file | Fl q Ar file | Fl t
83 .Op Fl S Ar var Ns Op Ns = Ns Ar value
88 .Op Fl Fl \~ Ns Ar mta-option ...
97 .Op Fl S Ar var Ns Op Ns = Ns Ar value
100 .Op Fl Fl \~ Ns Ar mta-option ...
108 .Op Fl L Ar spec-list
109 .Op Fl r Ar from-addr
110 .Op Fl S Ar var Ns Op Ns = Ns Ar value
113 .Op Fl Fl \~ Ns Ar mta-option ...
118 .Mx -toc -tree html pdf ps xhtml
121 .\" .Sh DESCRIPTION {{{
124 .Bd -filled -compact -offset indent
125 .Sy Compatibility note:
126 S-nail (\*(UA) will wrap up into \%S-mailx in v15.0 (circa 2018).
127 Backward incompatibility has to be expected \(en
131 -style argument quoting rules, for example.
132 New and old behaviour is flagged \*(IN and \*(OU, and setting
135 .Sx "INTERNAL VARIABLES" ,
136 will choose new behaviour when applicable.
137 \*(OB flags what will vanish, and enabling
141 enables obsoletion warnings.
145 \*(UA is a mail processing system with a command syntax reminiscent of
147 with lines replaced by messages.
148 It is intended to provide the functionality of the POSIX
150 command, but is MIME capable and optionally offers extensions for
151 line editing, S/MIME, SMTP and POP3 among others.
153 .\" .Ss "Options" {{{
156 .Bl -tag -width ".It Fl BaNg"
159 Explicitly control which of the
161 shall be loaded: if the letter
163 is (case-insensitively) part of the
167 is loaded, likewise the letter
169 controls loading of the user's personal
171 file, whereas the letters
175 explicitly forbid loading of any resource files.
176 This option should be used by scripts: to avoid environmental noise they
179 from any configuration files and create a script-local environment,
180 explicitly setting any of the desired
181 .Sx "INTERNAL VARIABLES"
184 This option overrides
191 command for the given user email
193 after program startup is complete (all resource files are loaded, any
195 setting is being established; only
197 commands have not been evaluated yet).
198 Being a special incarnation of
200 macros for the purpose of bundling longer-lived settings, activating
201 such an email account also switches to the accounts
203 .Sx "primary system mailbox"
208 .It Fl a Ar file Ns Op Ar =input-charset Ns Op Ar #output-charset
211 to the message (for compose mode opportunities refer to
217 .Sx "filename transformations"
218 as described in the section
222 apply, but shell word expansion is restricted to the tilde
226 not be accessible but contain a
228 character, then anything after the
230 is treated as a character-set specification.
232 If an input character-set is specified,
233 .Mx -ix "character-set specification"
234 but no output character-set, then the given input character-set is fixed
235 as-is, and no conversion will be applied;
236 giving the special string hyphen
238 will be treated as if
240 has been specified (the default).
241 If an output character-set has also been given then the conversion will
242 be performed exactly as specified and on-the-fly, not considering the
243 file's type and content.
244 As an exception, if the output character-set is specified as the hyphen
246 then the default conversion algorithm (see
247 .Sx "Character sets" )
248 is applied (therefore no conversion is performed on-the-fly,
250 will be MIME-classified and its contents will be inspected first).
251 It is an error to specify anything but
253 if no character-set conversion is available
255 does not include the term
260 (\*(OB: \*(UA will always use line-buffered output, to gain
261 line-buffered input even in batch mode enable batch mode via
266 Send a blind carbon copy to
268 ess, if the setting of
271 .Sx "INTERNAL VARIABLES" ,
273 The option may be used multiple times.
275 .Sx "On sending mail, and non-interactive mode" .
279 Send carbon copies to the given receiver, if so allowed by
281 May be used multiple times.
286 the internal variable
288 which enables debug messages and disables message delivery,
289 among others; effectively turns almost any operation into a dry-run.
295 and thus discard messages with an empty message part body.
296 This command line flag is \*(OB.
300 Just check if mail is present (in the specified or system
302 if yes, return an exit status of zero, a non-zero value otherwise.
303 To restrict the set of mails to consider in this evaluation a message
304 specification can be added with the option
309 Save the message to send in a file named after the local part of the
310 first recipient's address (instead of in
315 Read in the contents of the user's
317 (or the specified file) for processing;
318 when \*(UA is quit, it writes undeleted messages back to this file
324 argument will undergo some special
326 .Sx "filename transformations" ,
327 which are documented in the introductional section of
329 as well as for the command
333 is not a argument to the flag
335 but is instead taken from the command line after option processing has
339 that starts with a hyphen, prefix it with a (relative) path, as in
340 .Ql ./-hyphenbox.mbox .
344 Display a summary of the
346 of all messages in the specified mailbox or system
349 A configurable summary view is available via the
355 Show a short usage summary.
356 Because of widespread use a
358 argument will have the same effect.
364 to ignore tty interrupt signals.
367 .It Fl L Ar spec-list
368 Display a summary of all
370 of only those messages in the specified mailbox or the system
376 .Sx "Specifying messages"
383 option has been given in addition no header summary is produced,
384 but \*(UA will instead indicate via its exit status whether
390 note that any verbose output is suppressed in this mode and must instead
391 be enabled explicitly (e.g., by using the option
396 Special send mode that will flag standard input with the MIME
400 and use it as the main message body.
401 \*(ID Using this option will bypass processing of
402 .Va message-inject-head ,
405 .Va message-inject-tail .
411 Special send mode that will MIME classify the specified
413 and use it as the main message body.
414 \*(ID Using this option will bypass processing of
415 .Va message-inject-head ,
418 .Va message-inject-tail .
424 inhibit the initial display of message headers when reading mail or
425 editing a mail folder by calling
427 for the internal variable
432 Standard flag that inhibits reading the system wide
437 allows more control over the startup sequence; also see
438 .Sx "Resource files" .
442 Special send mode that will initialize the message body with the
443 contents of the specified
445 which may be standard input
447 only in non-interactive context.
453 Any folder opened will be in read-only mode.
457 .It Fl r Ar from-addr
458 The source address that appears in the
461 header of a message (or in the
464 header if the former contains multiple addresses) is not used for
465 relaying and delegating a message over the wire via SMTP, but instead an
466 envelope will enwrap the message content and provide the necessary
467 information (i.e., the RFC 5321 reverse-path, also used to report, e.g.,
468 delivery errors) to transmit the message to its destination(s).
469 Whereas the said headers and internal variables will be used by \*(UA to
470 create the envelope if the builtin SMTP
472 (Mail-Transfer-Agent) is used, a file-based MTA will instead use the
473 identity of the message-originating user.
475 This command line option can be used to specify the reverse-path, to be
476 passed to a file-based
478 when a message is sent, via
479 .Ql -f Ar from-addr .
482 include a user name, then the address components will be separated and
483 the name part will be passed to a file-based
489 is also assigned to the internal variable
491 Many default installations and sites disallow explicit overriding of the
492 user identity which could be adjusted by this option, unless either
494 has been configured accordingly, or the user is member of a group with
495 special privileges, respectively.
497 If an empty string is passed as
499 then the content of the variable
501 (or, if that contains multiple addresses,
503 will be evaluated and used for this purpose whenever the file-based
506 Note that \*(UA by default, without
508 that is, neither passes
512 flags to a file-based MTA by itself, unless this automatic deduction is
515 ing the internal variable
516 .Va r-option-implicit .
520 .It Fl S Ar var Ns Op = Ns value
524 iable and, in case of a non-boolean variable which has a value, assign
528 .Sx "INTERNAL VARIABLES"
532 may be overwritten from within resource files,
533 the command line setting will be reestablished after all resource files
538 Specify the subject of the message to be sent.
539 Newline (NL) and carriage-return (CR) bytes are invalid and will be
540 normalized to space (SP) characters.
544 The message given (on standard input) is expected to contain, separated
545 from the message body by an empty line, a message header with
550 fields giving its recipients, which will be added to any recipients
551 specified on the command line.
552 If a message subject is specified via
554 then it will be used in favour of one given on the command line.
570 .Ql Mail-Followup-To: ,
571 by default created automatically dependent on message context, will
572 be used if specified (a special address massage will however still occur
574 Any other custom header field (also see
577 is passed through entirely
578 unchanged, and in conjunction with the option
580 it is possible to embed
581 .Sx "COMMAND ESCAPES" .
589 .Sx "primary system mailbox"
592 appropriate privileges presumed; effectively identical to
602 will also show the list of
604 .Ql $ \*(uA -Xversion -Xx .
609 ting the internal variable
611 enables display of some informational context messages.
612 Using it twice increases the level of verbosity.
616 Add the given (or multiple for a multiline argument)
618 to the list of commands to be executed (as a unit, just as via
620 as a last step of program startup, before normal operation starts.
624 .Va batch-exit-on-error ;
625 the only possibility to execute commands in non-interactive mode when
626 reading startup files is actively prohibited.
631 .Sx "COMMAND ESCAPES"
632 even if not in interactive mode.
633 This can be used to, e.g., automatically format the composed message
634 text before sending the message:
635 .Bd -literal -offset indent
636 $ ( echo 'line one. Word. Word2.'; \e
637 echo '~| /usr/bin/fmt -tuw66' ) |\e
638 LC_ALL=C \*(uA -:/ -Sttycharset=utf-8 -d~ bob@exam.ple
644 In batch mode the full set of commands is available, just like in
645 interactive mode, standard input is made line buffered, and diverse
646 .Sx "INTERNAL VARIABLES"
647 are adjusted for batch necessities, e.g., it
663 .Sx "COMMAND ESCAPES"
664 is enabled in compose mode.
665 The following prepares an email message in a batched dry run:
666 .Bd -literal -offset indent
667 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en~.\enx\en' | \e
668 LC_ALL=C \*(uA -:/ -d# -X'alias bob bob@exam.ple'
673 This flag forces termination of option processing in order to prevent
676 It also forcefully puts \*(UA into send mode, see
677 .Sx "On sending mail, and non-interactive mode" .
685 argument, as well as all receivers established by the command line options
689 are subject to checks established via
692 .Sx "INTERNAL VARIABLES" .
694 .Op Ar mta-option ...
696 arguments that are given at the end of the command line after a
698 separator will be passed through to a file-based
700 (Mail-Transfer-Agent) and persist for an entire (interactive) session
701 \(en if the setting of the internal variable
703 allows their recognition; no such constraints apply to the variable
707 .\" .Ss "A starter" {{{
710 \*(UA is a direct descendant of
712 Mail, a successor of the Research
715 .Dq was there from the start
720 Mail reference manual begins with the following words:
722 .Bd -ragged -offset indent
723 Mail provides a simple and friendly environment for sending and
725 It divides incoming mail into its constituent messages and allows the
726 user to deal with them in any order.
727 In addition, it provides a set of
729 -like commands for manipulating messages and sending mail.
730 Mail offers the user simple editing capabilities to ease the composition
731 of outgoing messages, as well as providing the ability to define and
732 send to names which address groups of users.
736 \*(UA is thus the user side of the
738 mail system, whereas the system side (Mail-Transfer-Agent, MTA) was
739 traditionally taken by
741 and most MTAs provide a binary of this name for compatibility purposes.
746 of \*(UA then the system side is not a mandatory precondition for mail
750 Because \*(UA strives for compliance with POSIX
752 it is likely that some configuration settings have to be adjusted before
753 using it is a smooth experience.
756 resource file bends those standard imposed settings of the
757 .Sx "INTERNAL VARIABLES"
758 a bit towards more user friendliness and safety, however, e.g., it
763 in order to suppress the automatic moving of messages to
765 that would otherwise occur (see
766 .Sx "Message states" ) ,
769 to not remove empty system (MBOX) mailbox files in order not to mangle
770 file permissions when files eventually get recreated; be aware that
771 \*(UA will (try to) remove all empty (MBOX) mailbox files unless this
772 variable is set in case
774 .Pf ( Ev POSIXLY_CORRECT )
775 mode has been enabled.
776 The file mode creation mask is explicitly managed via
782 in order to synchronize \*(UA with the exit status report of the used
787 to enter interactive startup even if the initial mailbox is empty,
789 to allow editing of headers as well as
791 to not strip down addresses in compose mode, and
793 to include the message that is being responded to when
798 contains some more complete configuration examples.
801 .\" .Ss "On sending mail, and non-interactive mode" {{{
802 .Ss "On sending mail, and non-interactive mode"
804 To send a message to one or more people, using a local or a builtin
806 (Mail-Transfer-Agent) transport to actually deliver the generated mail
807 message, \*(UA can be invoked with arguments which are the names of
808 people to whom the mail will be sent, and the command line options
812 can be used to add (blind) carbon copy receivers:
814 .Bd -literal -offset indent
815 $ \*(uA -s ubject -a ttach.txt bill@exam.ple
816 # But... try it in an isolated dry-run mode first
817 $ LC_ALL=C \*(uA -:/ -d -vv -Ssendwait \e
818 -b bcc@exam.ple -c cc@exam.ple -. \e
819 '(Lovely) Bob <bob@exam.ple>' eric@exam.ple
821 $ LC_ALL=C \*(uA -:/ -d -vv -Sv15-compat -Ssendwait \e
822 -S 'mta=smtps://mylogin@exam.ple:465' -Ssmtp-auth=login \e
823 -S 'from=scriptreply@exam.ple' \e
829 If standard input is a terminal rather than the message to be sent,
830 the user is expected to type in the message contents.
831 In this compose mode \*(UA treats lines beginning with the character
833 special \(en these are so-called
834 .Sx "COMMAND ESCAPES"
835 which can be used to read in files, process shell commands, add and edit
836 attachments and more; e.g., the command escape
838 will start the text editor to revise the message in its current state,
840 allows editing of the most important message headers and
842 gives an overview of available command escapes.
846 at the beginning of an empty line leaves compose mode and causes the
847 message to be sent, whereas typing
850 twice will abort the current letter (saving its contents in the file
856 Messages are sent asynchronously, without supervision, unless the variable
858 is set, therefore send errors are not recognizable until then.
864 .Sx "INTERNAL VARIABLES"
865 can be used to alter default behavior; e.g.,
870 will automatically startup a text editor when compose mode is entered,
872 allows editing of headers additionally to plain body content,
874 will cause the user to be prompted actively for carbon-copy recipients
877 will allow leaving compose mode by writing a line consisting solely of
883 hook macros may be set to automatically adjust some settings dependent
884 on receiver, sender or subject contexts, and
885 .Va on-compose-done-shell
888 are increasingly powerful mechanisms to perform automated message
889 adjustments in between.
892 Especially for using public mail provider accounts with the SMTP
894 it is often necessary to set
896 and saving a copy of sent messages in a
898 may be desirable \(en as for most mailbox
900 targets the value will undergo
902 .Sx "filename transformations" ,
903 also see the introduction of
908 for the purpose of arranging a complete environment of settings that can
909 be switched to with a single command or command line option may be
912 contains example configurations for sending messages via some of the
913 well-known public mail providers and also gives a compact overview on
914 how to setup a secure SSL/TLS environment).
919 sandbox dry-run tests first will prove correctness.
923 .Sx "On URL syntax and credential lookup"
924 will spread light on the different ways of how to specify user email
925 account credentials, the
927 variable chains, and accessing protocol-specific resources,
930 goes into the details of character encoding and how to use them for
931 representing messages and MIME part contents by specifying them in
933 and reading the section
934 .Sx "The mime.types files"
935 should help to understand how the MIME-type of outgoing attachments are
936 classified, and what can be done for fine-tuning.
937 Over the wire an intermediate, configurable
938 .Pf content-transfer-\: Va encoding
939 may be applied to the raw message part data.
942 Message recipients (as specified on the command line or defined in
947 may not only be email addressees but can also be names of mailboxes and
948 even complete shell command pipe specifications.
951 is not set then only network addresses (see
953 for a description of mail addresses) and plain user names (including MTA
954 aliases) may be used, other types will be filtered out, giving a warning
957 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
958 .\" grep the latter for the complete picture
962 is set then extended recipient addresses will optionally be accepted:
963 Any name which starts with a vertical bar
965 character specifies a command pipe \(en the command string following the
967 is executed and the message is sent to its standard input;
968 Likewise, any name that starts with the character solidus
970 or the character sequence dot solidus
972 is treated as a file, regardless of the remaining content;
973 likewise a name that solely consists of a hyphen
975 Any other name which contains an at sign
977 character is treated as a network address;
978 Any other name which starts with a plus sign
980 character specifies a mailbox name;
981 Any other name which contains a solidus
983 character but no exclamation mark
987 character before also specifies a mailbox name;
988 What remains is treated as a network address.
990 .Bd -literal -offset indent
991 $ echo bla | \*(uA -Sexpandaddr -s test ./mbox.mbox
992 $ echo bla | \*(uA -Sexpandaddr -s test '|cat >> ./mbox.mbox'
993 $ echo safe | LC_ALL=C \e
994 \*(uA -:/ -Sv15-compat -Ssendwait -Snosave \e
995 -Sexpandaddr=fail,-all,+addr -s test \e
1000 It is possible to create personal distribution lists via the
1002 command, so that, for instance, the user can send mail to
1004 and have it go to a group of people.
1005 These aliases have nothing in common with the system wide aliases that
1006 may be used by the MTA, which are subject to the
1010 and are often tracked in a file
1016 Personal aliases will be expanded by \*(UA before the message is sent,
1017 and are thus a convenient alternative to specifying each addressee by
1021 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
1024 To avoid environmental noise scripts should
1026 \*(UA from any configuration files and create a script-local
1027 environment, ideally with the command line options
1029 to disable any configuration file in conjunction with repetitions of
1031 to specify variables:
1033 .Bd -literal -offset indent
1034 $ env LC_ALL=C \*(uA -:/ \e
1035 -Sv15-compat -Ssendwait -Snosave -Sttycharset=utf-8 \e
1036 -Sexpandaddr=fail,-all,+addr \e
1037 -S 'mta=smtps://mylogin@exam.ple:465' -Ssmtp-auth=login \e
1038 -S 'from=scriptreply@exam.ple' \e
1039 -s 'subject' -a attachment_file \e
1040 -. "Recipient 1 <rec1@exam.ple>" rec2@exam.ple \e
1045 As shown, scripts can
1047 a locale environment, the above specifies the all-compatible 7-bit clean
1050 but will nonetheless take and send UTF-8 in the message text by using
1052 In interactive mode, which is introduced in the next section, messages
1053 can be sent by calling the
1055 command with a list of recipient addresses \(em the semantics are
1056 completely identical to non-interactive message sending:
1058 .Bd -literal -offset indent
1059 $ \*(uA -d -Squiet -Semptystart
1060 "/var/spool/mail/user": 0 messages
1061 ? mail "Recipient 1 <rec1@exam.ple>", rec2@exam.ple
1062 ? # Will do the right thing (tm)
1063 ? m rec1@exam.ple rec2@exam.ple
1067 .\" .Ss "On reading mail, and interactive mode" {{{
1068 .Ss "On reading mail, and interactive mode"
1070 When invoked without addressees \*(UA enters interactive mode in which
1072 When used like that the user's system
1076 for an in-depth description of the different mailbox types that exist)
1077 is read in and a one line header of each message therein is displayed.
1078 The visual style of this summary of
1080 can be adjusted through the variable
1082 and the possible sorting criterion via
1088 can be performed with the command
1090 If the initially opened mailbox is empty \*(UA will instead exit
1091 immediately (after displaying a message) unless the variable
1100 will give a listing of all available commands and
1102 will give a summary of some common ones.
1103 If the \*(OPal documentation strings are available one can type
1106 and see the actual expansion of
1108 and what its purpose is, i.e., commands can be abbreviated
1109 (note that POSIX defines some abbreviations, so that the alphabetical
1110 order of commands does not necessarily relate to the abbreviations; it is
1111 possible to define overwrites with the
1114 These commands can also produce a more
1119 Messages are given numbers (starting at 1) which uniquely identify
1120 messages; the current message \(en the
1122 \(en will either be the first new message, or the first unread message,
1123 or the first message of the mailbox; the internal variable
1125 will instead cause usage of the last message for this purpose.
1130 ful of header summaries containing the
1134 will display only the summaries of the given messages, defaulting to the
1138 Message content can be displayed on the users' terminal with the
1142 If instead the command
1144 is used, only the first
1146 of a message will be shown.
1147 By default the current message
1149 is displayed, but like with many other commands it is possible to give
1150 a fancy message specification (see
1151 .Sx "Specifying messages" ) ,
1154 will display all unread messages,
1159 will type the messages 1 and 5,
1161 will type the messages 1 through 5, and
1165 will display the last and the next message, respectively.
1168 (a more substantial alias of the standard command
1170 will display a header summary of the given message specification list
1171 instead of their content, e.g., the following will search for subjects:
1174 .Dl from "'@Some subject to search for'"
1177 In the default setup all header fields of a message will be
1179 d, but fields can be white- or blacklisted for a variety of
1180 applications by using the command
1182 e.g., to restrict display to a very restricted set:
1183 .Ql Ic \:headerpick Cd \:type retain add Ar \:from to cc subject .
1184 In order to display all header fields of a message regardless of
1185 currently active ignore or retain lists, use the commands
1191 controls whether and when \*(UA will use the configured
1193 for display instead of directly writing to the user terminal
1195 (generally speaking).
1196 Note that historically the global
1198 not only adjusts the list of displayed headers, but also sets
1202 Dependent upon the configuration a line editor (see the section
1203 .Sx "On terminal control and line editor" )
1204 aims at making user experience with the many
1207 When reading the system
1213 specified a mailbox explicitly prefixed with the special
1215 modifier (propagating the mailbox to a
1217 .Sx "primary system mailbox" ) ,
1218 then messages which have been read will be moved to a
1220 .Sx "secondary mailbox" ,
1223 file, automatically when the mailbox is left, either by changing the
1224 active mailbox or by quitting \*(UA (also see
1225 .Sx "Message states" )
1226 \(en this automatic moving from a system or primary to the secondary
1227 mailbox is not performed when the variable
1232 After examining a message the user can also
1236 to the sender and all recipients or
1238 exclusively to the sender(s).
1239 Messages can also be
1241 ed (shorter alias is
1243 Note that when replying to or forwarding a message recipient addresses
1244 will be stripped from comments and names unless the internal variable
1247 Deletion causes \*(UA to forget about the message;
1248 This is not irreversible, though, one can
1250 the message by giving its number,
1251 or the \*(UA session can be ended by giving the
1256 To end a mail processing session one may either issue
1258 to cause a full program exit, which possibly includes
1259 automatic moving of read messages to
1261 as well as updating the \*(OPal line editor
1265 instead in order to prevent any of these actions.
1268 .\" .Ss "HTML mail and MIME attachments" {{{
1269 .Ss "HTML mail and MIME attachments"
1271 Messages which are HTML-only get more and more common and of course many
1272 messages come bundled with a bouquet of MIME attachments.
1273 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1274 with HTML messages (see
1275 .Sx "The mime.types files" ) ,
1276 it normally cannot deal with any of these itself, but instead programs
1277 need to become registered to deal with specific MIME types or file
1279 These programs may either prepare plain text versions of their input
1280 in order to enable \*(UA to display the content on the terminal,
1281 or display the content themselves, for example in a graphical window.
1284 To install an external handler program for a specific MIME type set an
1286 .Va pipe-TYPE/SUBTYPE
1287 variable; to instead define a handler for a specific file extension set
1290 variable \(en these handlers take precedence.
1291 \*(OPally \*(UA supports mail user agent configuration as defined in
1292 RFC 1524; this mechanism, documented in the section
1293 .Sx "The Mailcap files" ,
1294 will be queried for display or quote handlers if none of the former two
1295 .\" TODO v15-compat "will be" -> "is"
1296 did; it will be the sole source for handlers of other purpose.
1297 A last source for handlers may be the MIME type definition itself, if
1298 the \*(UA specific type-marker extension was used when defining the type
1301 (Many of the builtin MIME types do so by default.)
1305 .Va mime-counter-evidence
1306 can be set to improve dealing with faulty MIME part declarations as are
1307 often seen in real-life messages.
1308 E.g., to display a HTML message inline (that is, converted to a more
1309 fancy plain text representation than the builtin converter is capable to
1310 produce) with either of the text-mode browsers
1314 teach \*(UA about MathML documents and make it display them as plain
1315 text, and to open PDF attachments in an external PDF viewer,
1316 asynchronously and with some other magic attached:
1318 .Bd -literal -offset indent
1319 if $features !@ +filter-html-tagsoup
1320 #set pipe-text/html='elinks -force-html -dump 1'
1321 set pipe-text/html='lynx -stdin -dump -force_html'
1322 # Display HTML as plain text instead
1323 #set pipe-text/html=@
1325 mimetype '@ application/mathml+xml mathml'
1326 wysh set pipe-application/pdf='@&=@ \e
1327 trap "rm -f \e"${NAIL_FILENAME_TEMPORARY}\e"" EXIT;\e
1328 trap "trap \e"\e" INT QUIT TERM; exit 1" INT QUIT TERM;\e
1329 mupdf "${NAIL_FILENAME_TEMPORARY}"'
1333 Note: special care must be taken when using such commands as mail
1334 viruses may be distributed by this method: if messages of type
1335 .Ql application/x-sh
1336 or files with the extension
1338 were blindly filtered through the shell, for example, a message sender
1339 could easily execute arbitrary code on the system \*(UA is running on.
1340 For more on MIME, also in respect to sending of messages, see the
1342 .Sx "The mime.types files" ,
1343 .Sx "The Mailcap files"
1348 .\" .Ss "Mailing lists" {{{
1351 \*(UA offers some support to ease handling of mailing lists.
1354 promotes all given arguments to known mailing lists, and
1356 sets their subscription attribute, creating them first as necessary.
1361 automatically, but only resets the subscription attribute.)
1362 Using the commands without arguments will show (a subset of) all
1363 currently defined mailing lists.
1368 can be used to mark out messages with configured list addresses
1369 in the header display.
1372 \*(OPally mailing lists may also be specified as (extended) regular
1373 expressions, which allows matching of many addresses with a single
1375 However, all fully qualified list addresses are matched via a fast
1376 dictionary, whereas expressions are placed in (a) list(s) which is
1377 (are) matched sequentially.
1379 .Bd -literal -offset indent
1380 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1381 wysh mlist a1@b1.c1 a2@b2.c2 '.*@lists\e.c3$'
1382 mlsubscribe a4@b4.c4 exact@lists.c3
1387 .Va followup-to-honour
1389 .Ql Mail-\:Followup-\:To:
1390 header is honoured when the message is being replied to (via
1396 controls whether this header is created when sending mails; it will be
1397 created automatically for a couple of reasons, too, like when the
1399 .Dq mailing list specific
1404 is used to respond to a message with its
1405 .Ql Mail-Followup-To:
1409 A difference in between the handling of known and subscribed lists is
1410 that the address of the sender is usually not part of a generated
1411 .Ql Mail-Followup-To:
1412 when addressing the latter, whereas it is for the former kind of lists.
1413 Usually because there are exceptions: say, if multiple lists are
1414 addressed and not all of them are subscribed lists.
1416 For convenience \*(UA will, temporarily, automatically add a list
1417 address that is presented in the
1419 header of a message that is being responded to to the list of known
1421 Shall that header have existed \*(UA will instead, dependent on the
1423 .Va reply-to-honour ,
1426 for this purpose in order to accept a list administrators' wish that
1427 is supposed to have been manifested like that (but only if it provides
1428 a single address which resides on the same domain as what is stated in
1432 .\" .Ss "Resource files" {{{
1433 .Ss "Resource files"
1435 Upon startup \*(UA reads in several resource files:
1437 .Bl -tag -width ".It Pa BaNg"
1440 System wide initialization file.
1441 Reading of this file can be suppressed, either by using the
1445 command line options, or by setting the
1448 .Ev NAIL_NO_SYSTEM_RC .
1452 File giving initial commands.
1453 A different file can be chosen by setting the
1457 Reading of this file can be suppressed with the
1459 command line option.
1461 .It Va NAIL_EXTRA_RC
1462 Can be used to define an optional startup file to be read after all
1463 other resource files.
1464 It can be used to specify settings that are not understood by other
1466 implementations, for example.
1467 This variable is only honoured when defined in a resource file, e.g.,
1469 .Sx "INTERNAL VARIABLES" .
1473 The content of these files is interpreted as follows:
1476 .Bl -bullet -compact
1478 A lines' leading whitespace is removed.
1480 Empty lines are ignored.
1482 Any other line is interpreted as a command.
1483 It may be spread over multiple input lines if the newline character is
1485 by placing a reverse solidus character
1487 as the last character of the line; whereas any leading whitespace of
1488 follow lines is ignored, trailing whitespace before a escaped newline
1489 remains in the input.
1491 If the line (content) starts with the number sign
1493 then it is a comment-command \(en a real command! \(en and also ignored.
1494 This command is the only form of comment that is understood.
1498 Unless \*(UA is about to enter interactive mode syntax errors that occur
1499 while loading these files are treated as errors and cause program exit.
1500 More files with syntactically equal content can be
1502 The following, saved in a file, would be an examplary content:
1504 .Bd -literal -offset indent
1505 # This line is a comment command. And y\e
1506 es, it is really continued here.
1513 .\" .Ss "Character sets" {{{
1514 .Ss "Character sets"
1516 \*(OP \*(UA detects the character set of the terminal by using
1517 mechanisms that are controlled by the
1522 should give an overview); the \*(UA internal variable
1524 will be set to the detected terminal character set accordingly
1525 and will thus show up in the output of the commands
1531 However, a user supplied
1533 value is not overwritten by this detection mechanism: this
1535 must be used if the detection does not work properly,
1536 and it may be used to adjust the name of the locale character set.
1537 E.g., on BSD systems one may use a locale with the character set
1538 ISO8859-1, which is not a valid name for this character set; to be on
1539 the safe side, one may set
1541 to the correct name, which is ISO-8859-1.
1544 Note that changing the value does not mean much beside that,
1545 since several aspects of the real character set are implied by the
1546 locale environment of the system,
1547 and that stays unaffected by the content of an overwritten
1550 (This is mostly an issue when interactively using \*(UA, though.
1551 It is actually possible to send mail in a completely
1553 locale environment, an option that \*(UA's test-suite uses excessively.)
1556 If no character set conversion capabilities have been compiled into
1559 does not include the term
1563 will be the only supported character set,
1564 it is simply assumed that it can be used to exchange 8-bit messages
1565 (over the wire an intermediate
1566 .Pf content-transfer-\: Va encoding
1568 and the rest of this section does not apply;
1569 it may however still be necessary to explicitly set it if automatic
1570 detection fails, since in that case it defaults to the mentioned
1571 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1575 When reading messages, their text is converted into
1577 as necessary in order to display them on the users terminal.
1578 Unprintable characters and invalid byte sequences are detected
1579 and replaced by proper substitution characters (unless the variable
1581 was set once \*(UA was started).
1583 .Va charset-unknown-8bit
1584 to deal with another hairy aspect of message interpretation.
1587 When sending messages all their parts and attachments are classified.
1588 Whereas no character set conversion is performed on those parts which
1589 appear to be binary data,
1590 the character set being used must be declared within the MIME header of
1591 an outgoing text part if it contains characters that do not conform to
1592 the set of characters that are allowed by the email standards.
1593 Permissible values for character sets can be declared using the
1597 which defines a catch-all last-resort fallback character set that is
1598 implicitly appended to the list of character-sets in
1602 When replying to a message and the variable
1603 .Va reply-in-same-charset
1604 is set then the character set of the message being replied to is tried
1606 And it is also possible to make \*(UA work even more closely related to
1607 the current locale setting automatically by using the variable
1608 .Va sendcharsets-else-ttycharset ,
1609 please see there for more information.
1612 All the specified character sets are tried in order unless the
1613 conversion of the part or attachment succeeds.
1614 If none of the tried (8-bit) character sets is capable to represent the
1615 content of the part or attachment,
1616 then the message will not be sent and its text will optionally be
1620 In general, if the message
1621 .Dq Cannot convert from a to b
1622 appears, either some characters are not appropriate for the currently
1623 selected (terminal) character set,
1624 or the needed conversion is not supported by the system.
1625 In the first case, it is necessary to set an appropriate
1627 locale and/or the variable
1631 The best results are usually achieved when \*(UA is run in a UTF-8
1632 locale on a UTF-8 capable terminal, in which case the full Unicode
1633 spectrum of characters is available.
1634 In this setup characters from various countries can be displayed,
1635 while it is still possible to use more simple character sets for sending
1636 to retain maximum compatibility with older mail clients.
1639 On the other hand the POSIX standard defines a locale-independent 7-bit
1640 .Dq portable character set
1641 that should be used when overall portability is an issue, the even more
1642 restricted subset named
1643 .Dq portable filename character set
1644 consisting of A-Z, a-z, 0-9, period
1653 .\" .Ss "Message states" {{{
1654 .Ss "Message states"
1656 \*(UA differentiates in between several different message states;
1657 the current state will be reflected in header summary displays if
1659 is configured to do so (via the internal variable
1661 and messages can also be selected and be acted upon depending on their
1663 .Sx "Specifying messages" ) .
1664 When operating on the system
1668 .Sx "primary system mailbox" ,
1669 special actions, like the automatic moving of messages to the
1671 .Sx "secondary mailbox"
1673 may be applied when the mailbox is left (also implicitly via
1674 a successful exit of \*(UA, but not if the special command
1676 is used) \(en however, because this may be irritating to users which
1679 mail-user-agents, the default global
1685 variables in order to suppress this behaviour.
1687 .Bl -tag -width ".It Ql BaNg"
1689 Message has neither been viewed nor moved to any other state.
1690 Such messages are retained even in the
1692 .Sx "primary system mailbox" .
1695 Message has neither been viewed nor moved to any other state, but the
1696 message was present already when the mailbox has been opened last:
1697 Such messages are retained even in the
1699 .Sx "primary system mailbox" .
1702 The message has been processed by one of the following commands:
1722 commands may also cause the next message to be marked as read, depending
1728 command is used, messages that are in a
1730 .Sx "primary system mailbox"
1733 state when the mailbox is left will be saved in
1735 unless the internal variable
1740 The message has been processed by one of the following commands:
1746 can be used to access such messages.
1749 The message has been processed by a
1751 command and it will be retained in its current location.
1754 The message has been processed by one of the following commands:
1760 command is used, messages that are in a
1762 .Sx "primary system mailbox"
1765 state when the mailbox is left will be deleted; they will be saved in
1767 when the internal variable
1773 .\" .Ss "Specifying messages" {{{
1774 .Ss "Specifying messages"
1781 can be given a list of message numbers as arguments to apply to a number
1782 of messages at once.
1785 deletes messages 1 and 2,
1788 will delete the messages 1 through 5.
1789 In sorted or threaded mode (see the
1793 will delete the messages that are located between (and including)
1794 messages 1 through 5 in the sorted/threaded order, as shown in the
1797 The following special message names exist:
1800 .Bl -tag -width ".It Ar BaNg"
1802 The current message, the so-called
1806 The message that was previously the current message.
1809 The parent message of the current message,
1810 that is the message with the Message-ID given in the
1812 field or the last entry of the
1814 field of the current message.
1817 The next previous undeleted message,
1818 or the next previous deleted message for the
1821 In sorted/threaded mode,
1822 the next previous such message in the sorted/threaded order.
1825 The next undeleted message,
1826 or the next deleted message for the
1829 In sorted/threaded mode,
1830 the next such message in the sorted/threaded order.
1833 The first undeleted message,
1834 or the first deleted message for the
1837 In sorted/threaded mode,
1838 the first such message in the sorted/threaded order.
1842 In sorted/threaded mode,
1843 the last message in the sorted/threaded order.
1847 selects the message addressed with
1851 is any other message specification,
1852 and all messages from the thread that begins at it.
1853 Otherwise it is identical to
1858 the thread beginning with the current message is selected.
1863 All messages that were included in the message list for the previous
1867 An inclusive range of message numbers.
1868 Selectors that may also be used as endpoints include any of
1873 .Dq any substring matches
1876 header, which will match addresses (too) even if
1878 is set (and POSIX says
1879 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1882 variable is set, only the local part of the address is evaluated
1883 for the comparison, not ignoring case, and the setting of
1885 is completely ignored.
1886 For finer control and match boundaries use the
1890 .It Ar / Ns Ar string
1891 All messages that contain
1893 in the subject field (case ignored).
1900 the string from the previous specification of that type is used again.
1902 .It Xo Op Ar @ Ns Ar name-list Ns
1905 All messages that contain the given case-insensitive search
1907 ession; if the \*(OPal regular expression (see
1909 support is available
1911 will be interpreted as (an extended) one if any of the
1913 (extended) regular expression characters is seen.
1915 .Ar @ Ns Ar name-list
1916 part is missing, the search is restricted to the subject field body,
1919 specifies a comma-separated list of header fields to search, as in
1921 .Dl '@to,from,cc@Someone i ought to know'
1923 In order to search for a string that includes a
1925 (commercial at) character the
1927 is effectively non-optional, but may be given as the empty string.
1928 Some special header fields may be abbreviated:
1942 respectively and case-insensitively.
1947 can be used to search in (all of) the header(s) of the message, and the
1956 can be used to perform full text searches \(en whereas the former
1957 searches only the body, the latter also searches the message header.
1959 This message specification performs full text comparison, but even with
1960 regular expression support it is almost impossible to write a search
1961 expression that savely matches only a specific address domain.
1962 To request that the content of the header is treated as a list of
1963 addresses, and to strip those down to the plain email address which the
1964 search expression is to be matched against, prefix the header name
1965 (abbreviation) with a tilde
1968 .Dl @~f@@a\e.safe\e.domain\e.match$
1971 All messages of state
1975 is one or multiple of the following colon modifiers:
1977 .Bl -tag -compact -width ".It Ar :M"
1982 Old messages (any not in state
2008 Messages marked as draft.
2010 \*(OP Messages classified as spam.
2012 \*(OP Messages with unsure spam classification.
2018 \*(OP IMAP-style SEARCH expressions may also be used.
2019 This addressing mode is available with all types of folders;
2020 \*(UA will perform the search locally as necessary.
2021 Strings must be enclosed by double quotes
2023 in their entirety if they contain white space or parentheses;
2024 within the quotes, only reverse solidus
2026 is recognized as an escape character.
2027 All string searches are case-insensitive.
2028 When the description indicates that the
2030 representation of an address field is used,
2031 this means that the search string is checked against both a list
2034 .Bd -literal -offset indent
2035 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
2040 and the addresses without real names from the respective header field.
2041 These search expressions can be nested using parentheses, see below for
2045 .Bl -tag -compact -width ".It Ar _n_u"
2046 .It Ar ( criterion )
2047 All messages that satisfy the given
2049 .It Ar ( criterion1 criterion2 ... criterionN )
2050 All messages that satisfy all of the given criteria.
2052 .It Ar ( or criterion1 criterion2 )
2053 All messages that satisfy either
2058 To connect more than two criteria using
2060 specifications have to be nested using additional parentheses,
2062 .Ql (or a (or b c)) ,
2066 .Ql ((a or b) and c) .
2069 operation of independent criteria on the lowest nesting level,
2070 it is possible to achieve similar effects by using three separate
2074 .It Ar ( not criterion )
2075 All messages that do not satisfy
2077 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
2078 All messages that contain
2080 in the envelope representation of the
2083 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
2084 All messages that contain
2086 in the envelope representation of the
2089 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
2090 All messages that contain
2092 in the envelope representation of the
2095 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
2096 All messages that contain
2101 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
2102 All messages that contain
2104 in the envelope representation of the
2107 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
2108 All messages that contain
2113 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
2114 All messages that contain
2117 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
2118 All messages that contain
2120 in their header or body.
2121 .It Ar ( larger size )
2122 All messages that are larger than
2125 .It Ar ( smaller size )
2126 All messages that are smaller than
2130 .It Ar ( before date )
2131 All messages that were received before
2133 which must be in the form
2137 denotes the day of the month as one or two digits,
2139 is the name of the month \(en one of
2140 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
2143 is the year as four digits, e.g.,
2147 All messages that were received on the specified date.
2148 .It Ar ( since date )
2149 All messages that were received since the specified date.
2150 .It Ar ( sentbefore date )
2151 All messages that were sent on the specified date.
2152 .It Ar ( senton date )
2153 All messages that were sent on the specified date.
2154 .It Ar ( sentsince date )
2155 All messages that were sent since the specified date.
2157 The same criterion as for the previous search.
2158 This specification cannot be used as part of another criterion.
2159 If the previous command line contained more than one independent
2160 criterion then the last of those criteria is used.
2164 .\" .Ss "On URL syntax and credential lookup" {{{
2165 .Ss "On URL syntax and credential lookup"
2167 \*(IN For accessing protocol-specific resources usage of Uniform
2168 Resource Locators (URL, RFC 1738) has become omnipresent.
2169 \*(UA expects and understands URLs in the following form;
2172 denote optional parts, optional either because there also exist other
2173 ways to define the information in question or because support of the
2174 part is protocol-specific (e.g.,
2176 is used by the IMAP protocol but not by POP3);
2181 are specified they must be given in URL percent encoded form (RFC 3986;
2187 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
2190 Note that these \*(UA URLs most often do not conform to any real
2191 standard, but instead represent a normalized variant of RFC 1738 \(en
2192 they are not used in data exchange but only meant as a compact,
2193 easy-to-use way of defining and representing information in
2194 a well-known notation.
2197 Many internal variables of \*(UA exist in multiple versions, called
2198 variable chains for the rest of this document: the plain
2203 .Ql variable-USER@HOST .
2210 had been specified in the respective URL, otherwise it refers to the plain
2216 that had been found when doing the user chain lookup as is described
2219 will never be in URL percent encoded form, whether it came from an URL
2220 or not; i.e., variable chain name extensions of
2221 .Sx "INTERNAL VARIABLES"
2222 must not be URL percent encoded.
2225 For example, whether an hypothetical URL
2226 .Ql smtp://hey%3Ayou@our.house
2227 had been given that includes a user, or whether the URL was
2228 .Ql smtp://our.house
2229 and the user had been found differently, to lookup the variable chain
2230 .Va smtp-use-starttls
2231 \*(UA first looks for whether
2232 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
2233 is defined, then whether
2234 .Ql smtp-\:use-\:starttls-\:our.house
2235 exists before finally ending up looking at the plain variable itself.
2238 \*(UA obeys the following logic scheme when dealing with the
2239 necessary credential information of an account:
2245 has been given in the URL the variables
2249 are looked up; if no such variable(s) can be found then \*(UA will,
2250 when enforced by the \*(OPal variables
2251 .Va netrc-lookup-HOST
2258 specific entry which provides a
2260 name: this lookup will only succeed if unambiguous (one possible matching
2263 It is possible to load encrypted
2268 If there is still no
2270 then \*(UA will fall back to the user who is supposed to run \*(UA,
2271 the identity of which has been fixated during \*(UA startup and is
2272 known to be a valid user on the current host.
2275 Authentication: unless otherwise noted this will lookup the
2276 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
2277 variable chain, falling back to a protocol-specific default should this
2283 has been given in the URL, then if the
2285 has been found through the \*(OPal
2287 that may have already provided the password, too.
2288 Otherwise the variable chain
2289 .Va password-USER@HOST , password-HOST , password
2290 is looked up and used if existent.
2292 Afterwards the complete \*(OPal variable chain
2293 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2297 cache is searched for a password only (multiple user accounts for
2298 a single machine may exist as well as a fallback entry without user
2299 but with a password).
2301 If at that point there is still no password available, but the
2302 (protocols') chosen authentication type requires a password, then in
2303 interactive mode the user will be prompted on the terminal.
2308 S/MIME verification works relative to the values found in the
2312 header field(s), which means that the values of
2313 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2315 .Va smime-sign-message-digest
2316 will not be looked up using the
2320 chains from above but instead use the corresponding values from the
2321 message that is being worked on.
2322 In unusual cases multiple and different
2326 combinations may therefore be involved \(en on the other hand those
2327 unusual cases become possible.
2328 The usual case is as short as:
2331 .Dl set mta=smtp://USER:PASS@HOST smtp-use-starttls \e
2332 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2337 contains complete example configurations.
2340 .\" .Ss "On terminal control and line editor" {{{
2341 .Ss "On terminal control and line editor"
2343 \*(OP Terminal control will be realized through one of the standard
2345 libraries, either the
2347 or, alternatively, the
2349 both of which will be initialized to work with the environment variable
2351 Terminal control will enhance or enable interactive usage aspects, e.g.,
2352 .Sx "Coloured display" ,
2353 and extend behaviour of the Mailx-Line-Editor (MLE), which may learn the
2354 byte-sequences of keys like the cursor and function keys, and which will
2355 automatically enter the so-called
2357 alternative screen shall the terminal support it.
2358 The internal variable
2360 can be used to overwrite settings or to learn (correct(ed)) keycodes.
2361 Actual interaction with the chosen library can be disabled completely by
2362 setting the internal variable
2363 .Va termcap-disable ;
2365 will be queried regardless, even if the \*(OPal support for the
2366 libraries has not been enabled at configuration time.
2369 \*(OP The builtin \*(UA Mailx-Line-Editor (MLE) should work in all
2370 environments which comply to the ISO C standard
2372 and will support wide glyphs if possible (the necessary functionality
2373 had been removed from ISO C, but was included in
2375 Prevent usage of a line editor in interactive mode by setting the
2377 .Va line-editor-disable .
2378 Especially if the \*(OPal terminal control support is missing setting
2379 entries in the internal variable
2381 will help shall the MLE misbehave, see there for more.
2382 The MLE can support a little bit of
2388 feature is available then input from line editor prompts will be saved
2389 in a history list that can be searched in and be expanded from.
2390 Such saving can be prevented by prefixing input with any amount of
2392 Aspects of history, like allowed content and maximum size, as well as
2393 whether history shall be saved persistently, can be configured with the
2397 .Va history-gabby-persist
2402 The MLE supports a set of editing and control commands.
2403 By default (as) many (as possible) of these will be assigned to a set of
2404 single-letter control codes, which should work on any terminal (and can
2405 be generated by holding the
2407 key while pressing the key of desire, e.g.,
2411 command is available then the MLE commands can also be accessed freely
2412 by assigning the command name, which is shown in parenthesis in the list
2413 below, to any desired key-sequence, and the MLE will instead and also use
2415 to establish its builtin key bindings
2416 (more of them if the \*(OPal terminal control is available),
2417 an action which can then be suppressed completely by setting
2418 .Va line-editor-no-defaults .
2419 The following uses the
2421 ell-style quote notation that is documented in the introduction of
2423 combinations not mentioned either cause job control signals or do not
2424 generate a (unique) keycode:
2428 .Bl -tag -compact -width ".It Ql Ba"
2430 Go to the start of the line
2431 .Pf ( Cd mle-go-home ) .
2434 Move the cursor backward one character
2435 .Pf ( Cd mle-go-bwd ) .
2438 Forward delete the character under the cursor;
2439 quits \*(UA if used on the empty line unless the internal variable
2442 .Pf ( Cd mle-del-fwd ) .
2445 Go to the end of the line
2446 .Pf ( Cd mle-go-end ) .
2449 Move the cursor forward one character
2450 .Pf ( Cd mle-go-fwd ) .
2453 Cancel current operation, full reset.
2454 If there is an active history search or tabulator expansion then this
2455 command will first reset that, reverting to the former line content;
2456 thus a second reset is needed for a full reset in this case
2457 .Pf ( Cd mle-reset ) .
2460 Backspace: backward delete one character
2461 .Pf ( Cd mle-del-bwd ) .
2465 Horizontal tabulator:
2466 try to expand the word before the cursor, supporting the usual \*(UA
2468 .Sx "filename transformations" ,
2471 .Pf ( Cd mle-complete ) .
2473 .Cd mle-quote-rndtrip .
2477 commit the current line
2478 .Pf ( Cd mle-commit ) .
2481 Cut all characters from the cursor to the end of the line
2482 .Pf ( Cd mle-snarf-end ) .
2486 .Pf ( Cd mle-repaint ) .
2489 \*(OP Go to the next history entry
2490 .Pf ( Cd mle-hist-fwd ) .
2493 (\*(OPally context-dependent) Invokes the command
2497 \*(OP Go to the previous history entry
2498 .Pf ( Cd mle-hist-bwd ) .
2501 Toggle roundtrip mode shell quotes, where produced,
2503 .Pf ( Cd mle-quote-rndtrip ) .
2504 This setting is temporary, and will be forgotten once the command line
2508 \*(OP Complete the current line from (the remaining) older history entries
2509 .Pf ( Cd mle-hist-srch-bwd ) .
2512 \*(OP Complete the current line from (the remaining) newer history entries
2513 .Pf ( Cd mle-hist-srch-fwd ) .
2516 Paste the snarf buffer
2517 .Pf ( Cd mle-paste ) .
2524 .Pf ( Cd mle-snarf-line ) .
2527 Prompts for a Unicode character (its hexadecimal number) to be inserted
2528 .Pf ( Cd mle-prompt-char ) .
2529 Note this command needs to be assigned to a single-letter control code
2530 in order to become recognized and executed during input of
2531 a key-sequence (only three single-letter control codes can be used for
2532 that shortcut purpose); this control code is special-treated and cannot
2533 be part of any other sequence, because any occurrence will perform the
2535 function immediately.
2538 Cut the characters from the one preceding the cursor to the preceding
2540 .Pf ( Cd mle-snarf-word-bwd ) .
2543 Move the cursor forward one word boundary
2544 .Pf ( Cd mle-go-word-fwd ) .
2547 Move the cursor backward one word boundary
2548 .Pf ( Cd mle-go-word-bwd ) .
2551 Escape: reset a possibly used multibyte character input state machine
2552 and \*(OPally a lingering, incomplete key binding
2553 .Pf ( Cd mle-cancel ) .
2554 This command needs to be assigned to a single-letter control code in
2555 order to become recognized and executed during input of a key-sequence
2556 (only three single-letter control codes can be used for that shortcut
2558 This control code may also be part of a multi-byte sequence, but if
2559 a sequence is active and the very control code is currently also an
2560 expected input, then it will first be consumed by the active sequence.
2563 (\*(OPally context-dependent) Invokes the command
2567 (\*(OPally context-dependent) Invokes the command
2571 (\*(OPally context-dependent) Invokes the command
2575 Cut the characters from the one after the cursor to the succeeding word
2577 .Pf ( Cd mle-snarf-word-fwd ) .
2587 this will immediately reset a possibly active search etc.
2591 ring the audible bell.
2595 .\" .Ss "Coloured display" {{{
2596 .Ss "Coloured display"
2598 \*(OP \*(UA can be configured to support a coloured display and font
2599 attributes by emitting ANSI / ISO 6429 SGR (select graphic rendition)
2601 Usage of colours and font attributes solely depends upon the
2602 capability of the detected terminal type that is defined by the
2603 environment variable
2605 and which can be fine-tuned by the user via the internal variable
2609 On top of what \*(UA knows about the terminal the boolean variable
2611 defines whether the actually applicable colour and font attribute
2612 sequences should also be generated when output is going to be paged
2613 through the external program defined by the environment variable
2618 This is not enabled by default because different pager programs need
2619 different command line switches or other configuration in order to
2620 support those sequences.
2621 \*(UA however knows about some widely used pagers and in a clean
2622 environment it is often enough to simply set
2624 please refer to that variable for more on this topic.
2629 is set then any active usage of colour and font attribute sequences
2630 is suppressed, but without affecting possibly established
2635 To define and control colours and font attributes a single multiplexer
2636 command family exists:
2638 shows or defines colour mappings for the given colour type (e.g.,
2641 can be used to remove mappings of a given colour type.
2642 Since colours are only available in interactive mode, it may make
2643 sense to conditionalize the colour setup by encapsulating it with
2646 .Bd -literal -offset indent
2647 if terminal && $features =@ +colour
2648 colour iso view-msginfo ft=bold,fg=green
2649 colour iso view-header ft=bold,fg=red "from,subject"
2650 colour iso view-header fg=red
2652 uncolour iso view-header from,subject
2653 colour iso view-header ft=bold,fg=magenta,bg=cyan
2654 colour 256 view-header ft=bold,fg=208,bg=230 subject,from
2655 colour mono view-header ft=bold
2656 colour mono view-header ft=bold,ft=reverse subject,from
2660 .\" }}} (DESCRIPTION)
2663 .\" .Sh COMMANDS {{{
2666 Each command is typed on a line by itself,
2667 and may take arguments following the command word.
2668 Command names may be abbreviated, in which case the first command that
2669 matches the given prefix will be used.
2672 can be used to show the list of all commands, either alphabetically
2673 sorted or in prefix search order (these do not match, also because the
2674 POSIX standard prescribes a set of abbreviations).
2675 \*(OPally the command
2679 when given an argument, will show a documentation string for the
2680 command matching the expanded argument, as in
2682 which should be a shorthand of
2684 Both commands support a more
2686 listing mode which includes the argument type of the command.
2689 For commands which take message lists as arguments, the next message
2690 forward that satisfies the command's requirements will be used shall no
2691 explicit message list have been specified.
2692 If there are no messages forward of the current message,
2693 the search proceeds backwards,
2694 and if there are no good messages at all,
2695 \*(UA shows an error message and aborts the command.
2696 \*(ID Non-message-list arguments can be quoted using the following methods:
2699 .Bl -bullet -compact -offset indent
2701 An argument can be enclosed between paired double-quotes
2706 any white space, shell word expansion, or reverse solidus characters
2707 (except as described next) within the quotes are treated literally as
2708 part of the argument.
2709 A double-quote will be treated literally within single-quotes and vice
2711 Inside such a quoted string the actually used quote character can be
2712 used nonetheless by escaping it with a reverse solidus
2718 An argument that is not enclosed in quotes, as above, can usually still
2719 contain space characters if those spaces are reverse solidus escaped, as in
2723 A reverse solidus outside of the enclosing quotes is discarded
2724 and the following character is treated literally as part of the argument.
2729 Some commands which do not take message-list arguments can also be
2730 prefixed with the special keyword
2732 to choose \*(INible argument quoting rules, and some new commands only
2733 support the new rules (without that keyword) and are flagged \*(NQ.
2734 In the future \*(UA will (mostly) use
2736 compatible argument parsing:
2737 Non-message-list arguments can be quoted using the following shell-style
2738 mechanisms: the escape character, single-quotes, double-quotes and
2739 dollar-single-quotes; any unquoted number sign
2741 that parses as a new token starts a comment that ends argument processing.
2742 The overall granularity of error reporting and diagnostics, also
2743 regarding function arguments and their content, will improve.
2747 .Bl -bullet -compact -offset indent
2749 The literal value of any character can be preserved by preceding it
2750 with the escape character reverse solidus
2754 will cause variable expansion of the given name: \*(UA
2755 .Sx "INTERNAL VARIABLES"
2758 (shell) variables can be accessed through this mechanism, brace
2759 enclosing the name is supported.
2762 Arguments which are enclosed in
2763 .Ql 'single-\:quotes'
2764 retain their literal value.
2765 A single-quote cannot occur within single-quotes.
2768 The literal value of all characters enclosed in
2769 .Ql \(dqdouble-\:quotes\(dq
2770 is retained, with the exception of dollar
2772 which will cause variable expansion, as above, backquote (grave accent)
2774 (which not yet means anything special), reverse solidus
2776 which will escape any of the characters dollar
2778 (to prevent variable expansion), backquote (grave accent)
2782 (to prevent ending the quote) and reverse solidus
2784 (to prevent escaping, i.e., to embed a reverse solidus character as-is),
2785 but has no special meaning otherwise.
2788 Arguments enclosed in
2789 .Ql $'dollar-\:single-\:quotes'
2790 extend normal single quotes in that reverse solidus escape sequences are
2791 expanded as follows:
2793 .Bl -tag -compact -width "Ql \eNNN"
2799 an escape character.
2801 an escape character.
2813 emits a reverse solidus character.
2817 double quote (escaping is optional).
2819 eight-bit byte with the octal value
2821 (one to three octal digits), optionally prefixed by an additional
2823 A 0 byte will suppress further output for the quoted argument.
2825 eight-bit byte with the hexadecimal value
2827 (one or two hexadecimal characters).
2828 A 0 byte will suppress further output for the quoted argument.
2830 the Unicode / ISO-10646 character with the hexadecimal codepoint value
2832 (one to eight hexadecimal digits) \(em note that Unicode defines the
2833 maximum codepoint to be ever supported as
2838 This escape is only supported in locales which support Unicode (see
2839 .Sx "Character sets" ) ,
2840 in other cases the sequence will remain unexpanded unless the given code
2841 point is ASCII compatible or can be represented in the current locale.
2842 The character NUL will suppress further output for the quoted argument.
2846 except it takes only one to four hexadecimal digits.
2848 A mechanism that allows usage of the non-printable (ASCII and
2849 compatible) control codes 0 to 31: to create the printable
2850 representation of a control code the numeric value 64 is added, and the
2851 resulting ASCII character set code point is then printed, e.g., BEL is
2852 .Ql 7 + 64 = 71 = G .
2853 Whereas historically circumflex notation has often been used for
2854 visualization purposes of control codes, e.g.,
2856 the reverse solidus notation has been standardized:
2858 Some control codes also have standardized (ISO 10646, ISO C) alias
2859 representations, as shown above (e.g.,
2863 whenever such an alias exists \*(UA will use it for display purposes.
2864 The control code NUL
2866 ends argument processing without producing further output.
2868 Non-standard extension: expand the given variable name, as above.
2869 Brace enclosing the name is supported.
2871 Not yet supported, just to raise awareness: Non-standard extension.
2877 .Sy Compatibility notes:
2878 \*(ID Note these are new mechanisms which are not supported by all
2880 Round-tripping (feeding in things shown in list modes again) are not yet
2881 stable or possible at all.
2882 On new-style command lines it is wise to quote semicolon
2886 characters in order to ensure upward compatibility: the author would
2887 like to see things like
2888 .Ql ? echo $'trouble\etahead' | cat >> in_the_shell.txt
2890 .Ql ? top 2 5 10; type 3 22
2892 Before \*(UA will switch entirely to shell-style argument parsing there
2893 will be a transition phase where using
2895 will emit obsoletion warnings.
2897 .Bd -literal -offset indent
2898 echo 'Quotes '${HOME}' and 'tokens" differ!"# no comment
2899 echo Quotes ${HOME} and tokens differ! # comment
2900 echo Don"'"t you worry$'\ex21' The sun shines on us. $'\eu263A'
2904 In any event an unquoted reverse solidus at the end of a command line is
2905 discarded and the next line continues the command.
2906 \*(ID Note that line continuation is handled before the above parsing is
2907 applied, i.e., the parsers documented above will see merged lines.
2908 Filenames, where expected, and unless documented otherwise, are
2909 subsequently subjected to the following
2910 .Mx -ix "filename transformations"
2911 filename transformations, in sequence:
2914 .Bl -bullet -offset indent
2916 If the given name is a registered
2918 it will be replaced with the expanded shortcut.
2921 The filename is matched against the following patterns or strings:
2923 .Bl -hang -compact -width ".Ar %user"
2925 (Number sign) is expanded to the previous file.
2927 (Percent sign) is replaced by the invoking
2928 .Mx -ix "primary system mailbox"
2929 user's primary system mailbox, which either is the (itself expandable)
2931 if that is set, the standardized absolute pathname indicated by
2933 if that is set, or a builtin compile-time default otherwise.
2935 Expands to the primary system mailbox of
2937 (and never the value of
2939 regardless of its actual setting).
2941 (Ampersand) is replaced with the invoking users
2942 .Mx -ix "secondary mailbox"
2943 secondary mailbox, the
2950 directory (if that variable is set).
2952 Expands to the same value as
2954 but has special meaning for when used with, e.g., the command
2956 the file will be treated as a primary system mailbox by, e.g., the
2960 commands, meaning that messages that have been read in the current
2961 session will be moved to the
2963 mailbox instead of simply being flagged as read.
2967 Meta expansions are applied to the resulting filename: a leading tilde
2969 character will be replaced by the expansion of
2971 except when followed by a valid user name, in which case the home
2972 directory of the given user is used instead.
2977 will be replaced by the expansion of the variable, if possible; \*(UA
2978 .Sx "INTERNAL VARIABLES"
2981 (shell) variables can be accessed through this mechanism, and the usual
2982 escape mechanism has to be applied to prevent interpretation.
2983 If the fully expanded filename results in multiple pathnames and the
2984 command is expecting only one file, an error results.
2986 In interactive context, in order to allow simple value acceptance (via
2988 arguments will usually be displayed in a properly quoted form, e.g., a file
2989 .Ql diet\e is \ecurd.txt
2991 .Ql 'diet\e is \ecurd.txt' .
2996 The following commands are available:
2998 .Bl -tag -width ".It Ic BaNg"
3003 command which follows, replacing unescaped exclamation marks with the
3004 previously executed command if the internal variable
3010 The comment-command causes the entire line to be ignored.
3012 this really is a normal command which' purpose is to discard its
3015 indicating special character, which means that, e.g., trailing comments
3016 on a line are not possible.
3020 Goes to the next message in sequence and types it
3026 Display the preceding message, or the n'th previous message if given
3027 a numeric argument n.
3031 Show the current message number (the
3036 Show a brief summary of commands.
3039 output is available.
3040 \*(OP Given an argument a synopsis for the command in question is
3041 shown instead; commands can be abbreviated in general and this command
3042 can be used to see the full expansion of an abbreviation including the
3043 synopsis, try, e.g.,
3048 and see how the output changes.
3058 Interprets the remainder of the word as a macro name and passes it
3063 is a shorter synonym for
3064 .Ql call Ar mymacro .
3068 (ac) Creates, selects or lists (an) account(s).
3069 Accounts are special incarnations of
3071 macros and group commands and variable settings which together usually
3072 arrange the environment for the purpose of creating an email account.
3073 Different to normal macros settings which are covered by
3075 \(en here by default enabled! \(en will not be reverted before the
3080 (case-insensitive) always exists, and all but it can be deleted via
3083 Without arguments a listing of all defined accounts is shown.
3084 With one argument the given account is activated: the system
3086 of that account will be activated (as via
3088 and a possibly installed
3091 The two argument form is identical to defining a macro as via
3093 .Bd -literal -offset indent
3095 set folder=~/mail inbox=+syste.mbox record=+sent.mbox
3096 set from='myname@myisp.example (My Name)'
3097 set mta=smtp://mylogin@smtp.myisp.example
3103 (a) With no arguments, shows all currently-defined aliases.
3104 With one argument, shows that alias.
3105 With more than one argument,
3106 creates a new alias or appends to an existing one.
3108 can be used to delete aliases.
3112 (alt) Manage a list of alternate addresses / names of the active user,
3113 members of which will be removed from recipient lists when replying to
3116 variable is not set).
3117 If arguments are given the set of alternate names is replaced by them,
3118 without arguments the current set is displayed.
3122 Takes a message list and marks each message as having been answered.
3123 This mark has no technical meaning in the mail system;
3124 it just causes messages to be marked in the header summary,
3125 and makes them specially addressable.
3130 \*(OP\*(NQ The bind command extends the MLE (see
3131 .Sx "On terminal control and line editor" )
3132 with freely configurable key bindings.
3133 With one argument all bindings for the given context are shown,
3134 specifying an asterisk
3136 will show the bindings of all contexts; a more verbose listing will be
3137 produced if either of
3142 With two or more arguments a binding is (re)established:
3143 the first argument is the context to which the binding shall apply,
3144 the second argument is a comma-separated list of the
3146 which form the binding, and any remaining arguments form the expansion.
3147 To indicate that a binding shall not be auto-committed, but that the
3148 expansion shall instead be furtherly editable by the user, an at-sign
3150 (that will be removed) can be placed last in the expansion, from which
3151 leading and trailing whitespace will finally be removed.
3152 Reverse solidus cannot be used as the last character of expansion.
3155 Contexts define when a binding applies, i.e., a binding will not be seen
3156 unless the context for which it is defined for is currently active.
3157 This is not true for the shared binding
3159 which is the foundation for all other bindings and as such always
3160 applies, its bindings, however, only apply secondarily.
3161 The available contexts are the shared
3165 context which is used in all not otherwise documented situations, and
3167 which applies to compose mode only.
3171 which form the binding are specified as a comma-separated list of
3172 byte-sequences, where each list entry corresponds to one key(press).
3173 \*(OPally a list entry may, indicated by a leading colon character
3175 also refer to the name of a terminal capability;
3176 several dozen names will be compiled into \*(UA and may be specified
3179 or, if existing, by their
3181 name, regardless of the actually used terminal control library.
3182 It is however possible to use any capability, as long as the name is
3183 resolvable by the control library or defined in the internal variable
3185 Input sequences are not case-normalized, so that an exact match is
3186 required to update or remove a binding.
3189 .Bd -literal -offset indent
3190 bind base $'\eE',d mle-snarf-word-fwd # Esc(ape)
3191 bind base $'\eE',$'\ec?' mle-snarf-word-bwd # Esc, Delete
3192 bind default $'\ecA',:khome,w 'echo An editable binding@'
3193 bind default a,b,c rm -rf / @ # Another editable binding
3194 bind default :kf1 File %
3195 bind compose :kf1 ~e
3199 Note that the entire comma-separated list is first parsed (over) as a
3200 shell-token with whitespace as the field separator, before being parsed
3201 and expanded for real with comma as the field separator, therefore
3202 whitespace needs to be properly quoted:
3203 shell-style quoting is documented in the introduction of
3205 Using Unicode reverse solidus escape sequences renders a binding
3206 defunctional if the locale does not support Unicode (see
3207 .Sx "Character sets" ) ,
3208 and using terminal capabilities does so if no terminal control support
3209 is (currently) available.
3212 The following terminal capability names are builtin and can be used in
3214 or (if available) the two-letter
3216 notation regardless of the actually used library.
3217 See the respective manual for a list of capabilities.
3220 can be used to show all the capabilities of
3222 or the given terminal type;
3225 flag will also show supported (non-standard) extensions.
3228 .Bl -tag -compact -width kcuuf_or_kcuuf
3229 .It Cd kbs Ns \0or Cd kb
3231 .It Cd kdch1 Ns \0or Cd kD
3233 .It Cd kDC Ns \0or Cd *4
3234 \(em shifted variant.
3235 .It Cd kel Ns \0or Cd kE
3236 Clear to end of line.
3237 .It Cd kext Ns \0or Cd @9
3239 .It Cd kich1 Ns \0or Cd kI
3241 .It Cd kIC Ns \0or Cd #3
3242 \(em shifted variant.
3243 .It Cd khome Ns \0or Cd kh
3245 .It Cd kHOM Ns \0or Cd #2
3246 \(em shifted variant.
3247 .It Cd kend Ns \0or Cd @7
3249 .It Cd knp Ns \0or Cd kN
3251 .It Cd kpp Ns \0or Cd kP
3253 .It Cd kcub1 Ns \0or Cd kl
3254 Left cursor (with more modifiers: see below).
3255 .It Cd kLFT Ns \0or Cd #4
3256 \(em shifted variant.
3257 .It Cd kcuf1 Ns \0or Cd kr
3258 Right cursor (ditto).
3259 .It Cd kRIT Ns \0or Cd %i
3260 \(em shifted variant.
3261 .It Cd kcud1 Ns \0or Cd kd
3262 Down cursor (ditto).
3264 \(em shifted variant (only terminfo).
3265 .It Cd kcuu1 Ns \0or Cd ku
3268 \(em shifted variant (only terminfo).
3269 .It Cd kf0 Ns \0or Cd k0
3271 Add one for each function key up to
3276 .It Cd kf10 Ns \0or Cd k;
3278 .It Cd kf11 Ns \0or Cd F1
3280 Add one for each function key up to
3288 Some terminals support key-modifier combination extensions, e.g.,
3290 For example, the delete key,
3292 in its shifted variant, the name is mutated to
3294 then a number is appended for the states
3306 .Ql Shift+Alt+Control
3308 The same for the left cursor key,
3310 .Cd KLFT , KLFT3 , KLFT4 , KLFT5 , KLFT6 , KLFT7 , KLFT8 .
3313 Key bindings can be removed with the command
3315 It is advisable to use an initial escape or other control character (e.g.,
3317 for bindings which describe user key combinations (as opposed to purely
3318 terminal capability based ones), in order to avoid ambiguities whether
3319 input belongs to key sequences or not; it also reduces search time.
3322 may help shall keys and sequences be falsely recognized.
3327 Calls a macro that has been created via
3332 (ch) Change the working directory to
3334 or the given argument.
3340 \*(OP Only applicable to S/MIME signed messages.
3341 Takes a message list and a file name and saves the certificates
3342 contained within the message signatures to the named file in both
3343 human-readable and PEM format.
3344 The certificates can later be used to send encrypted messages to the
3345 respective message senders by setting
3346 .Va smime-encrypt-USER@HOST
3351 (ch) Change the working directory to
3353 or the given argument.
3359 Only applicable to threaded mode.
3360 Takes a message list and makes all replies to these messages invisible
3361 in header summaries, unless they are in state
3367 \*(OP\*(NQ Manage colour mappings of and for a
3368 .Sx "Coloured display" .
3369 The type of colour is given as the (case-insensitive) first argument,
3370 which must be one of
3372 for 256-colour terminals,
3377 for the standard 8-colour ANSI / ISO 6429 color palette and
3381 for monochrome terminals.
3382 Monochrome terminals cannot deal with colours, but only (some) font
3386 Without further arguments the list of all currently defined mappings
3387 for the given colour type is shown (as a special case giving
3391 will show the mappings of all types).
3392 Otherwise the second argument defines the mappable slot, and the third
3393 argument a (comma-separated list of) colour and font attribute
3394 specification(s), and the optional fourth argument can be used to
3395 specify a precondition: if conditioned mappings exist they are tested in
3396 (creation) order unless a (case-insensitive) match has been found, and
3397 the default mapping (if any has been established) will only be chosen as
3399 The types of precondition available depend on the mappable slot (see
3400 .Sx "Coloured display"
3401 for some examples), the following of which exist:
3404 Mappings prefixed with
3406 are used for the \*(OPal builtin Mailx-Line-Editor (MLE, see
3407 .Sx "On terminal control and line editor" )
3408 and do not support preconditions.
3410 .Bl -tag -compact -width view-partinfo
3412 This mapping is used for the position indicator that is visible when
3413 a line cannot be fully displayed on the screen.
3420 Mappings prefixed with
3422 are used in header summaries, and they all understand the preconditions
3424 (the current message) and
3426 for elder messages (only honoured in conjunction with
3427 .Va datefield-markout-older ) .
3429 .Bl -tag -compact -width view-partinfo
3431 This mapping is used for the
3433 that can be created with the
3437 formats of the variable
3440 For the complete header summary line except the
3442 and the thread structure.
3444 For the thread structure which can be created with the
3446 format of the variable
3451 Mappings prefixed with
3453 are used when displaying messages.
3455 .Bl -tag -compact -width view-partinfo
3457 This mapping is used for so-called
3459 lines, which are MBOX file format specific header lines.
3462 A comma-separated list of headers to which the mapping applies may be
3463 given as a precondition; if the \*(OPal regular expression support is
3464 available then if any of the
3466 (extended) regular expression characters is seen the precondition will
3467 be evaluated as (an extended) one.
3469 For the introductional message info line.
3470 .It Ar view-partinfo
3471 For MIME part info lines.
3475 The following (case-insensitive) colour definitions and font attributes
3476 are understood, multiple of which can be specified in a comma-separated
3486 It is possible (and often applicable) to specify multiple font
3487 attributes for a single mapping.
3490 foreground colour attribute:
3500 To specify a 256-color mode a decimal number colour specification in
3501 the range 0 to 255, inclusive, is supported, and interpreted as follows:
3503 .Bl -tag -compact -width "999 - 999"
3505 the standard ISO 6429 colors, as above.
3507 high intensity variants of the standard colors.
3509 216 colors in tuples of 6.
3511 grayscale from black to white in 24 steps.
3513 .Bd -literal -offset indent
3515 fg() { printf "\e033[38;5;${1}m($1)"; }
3516 bg() { printf "\e033[48;5;${1}m($1)"; }
3518 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
3519 printf "\e033[0m\en"
3521 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
3522 printf "\e033[0m\en"
3526 background colour attribute (see
3528 for possible values).
3532 Mappings may be removed with the command
3534 For a generic overview see the section
3535 .Sx "Coloured display" .
3540 (C) Copy messages to files whose names are derived from the author of
3541 the respective message and do not mark them as being saved;
3542 otherwise identical to
3547 (c) Copy messages to the named file and do not mark them as being saved;
3548 otherwise identical to
3553 Show the name of the current working directory.
3557 \*(OP For unencrypted messages this command is identical to
3559 Encrypted messages are first decrypted, if possible, and then copied.
3563 \*(OP For unencrypted messages this command is identical to
3565 Encrypted messages are first decrypted, if possible, and then copied.
3569 Without arguments the current list of macros, including their content,
3570 is shown, otherwise a macro is defined.
3571 A macro definition is a sequence of commands in the following form:
3572 .Bd -literal -offset indent
3581 A defined macro can be invoked explicitly by using the
3585 commands, or implicitly if a macro hook is triggered, e.g., a
3587 Note that interpretation of
3589 depends on how (i.e.,
3591 normal macro, folder hook, hook, account switch) the macro is invoked.
3592 Macros can be deleted via
3596 Macro behaviour, including option localization, will change in v15.
3597 One should be aware of that and possibly embed version checks in the
3598 used resource file(s).
3602 (d) Marks the given message list as
3604 Deleted messages will neither be saved in
3606 nor will they be available for most other commands.
3612 Superseded by the multiplexer
3618 Deletes the current message and displays the next message.
3619 If there is no next message, \*(UA says
3626 up or down by one message when given
3630 argument, respectively.
3634 Takes a message list and marks each given message as a draft.
3635 This mark has no technical meaning in the mail system;
3636 it just causes messages to be marked in the header summary,
3637 and makes them specially addressable.
3641 \*(NQ (ec) Echoes its arguments to standard output after applying
3643 expansions and filename transformations, as documented for
3650 except that is echoes to standard error.
3654 (e) Point the text editor (as defined in
3656 at each message from the given list in turn.
3657 Modified contents are discarded unless the
3664 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3665 conditional \(em if the condition of a preceding
3667 was false, check the following condition and execute the following block
3668 if it evaluates true.
3673 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3674 conditional \(em if none of the conditions of the preceding
3678 commands was true, the
3684 (en) Marks the end of an
3685 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3686 conditional execution block.
3691 \*(NQ \*(UA has a strict notion about which variables are
3692 .Sx "INTERNAL VARIABLES"
3693 and which are managed in the program
3695 Since some of the latter are a vivid part of \*(UAs functioning,
3696 however, they are transparently integrated into the normal handling of
3697 internal variables via
3701 To integrate other environment variables of choice into this
3702 transparent handling, and also to export internal variables into the
3703 process environment where they normally are not, a
3705 needs to become established with this command, as in, e.g.,
3708 .Dl environ link PERL5LIB from TZ
3711 Afterwards changing such variables with
3713 will cause automatic updates of the program environment, and therefore
3714 be inherited by newly created child processes.
3715 Sufficient system support provided (it was in BSD as early as 1987, and
3716 is standardized since Y2K) removing such variables with
3718 will remove them also from the program environment, but in any way
3719 the knowledge they ever have been
3722 Note this implies that
3724 may cause loss of links.
3729 will remove an existing link, but leaves the variables as such intact.
3730 Additionally the subcommands
3734 are provided, which work exactly the same as the documented commands
3738 but (additionally) link the variable(s) with the program environment and
3739 thus immediately export them to, or remove them from (if possible),
3740 respectively, the program environment.
3745 \*(OP Since \*(UA uses the console as a user interface it can happen
3746 that messages scroll by too fast to become recognized.
3747 Optionally an error message ring queue is available which stores
3748 duplicates of any error message and notifies the user in interactive
3749 sessions whenever a new error has occurred.
3750 The queue is finite: if its maximum size is reached any new message
3751 replaces the eldest.
3754 can be used to manage this message queue: if given
3756 or no argument the queue will be displayed and cleared,
3758 will only clear all messages from the queue.
3762 (ex or x) Exit from \*(UA without changing the active mailbox and skip
3763 any saving of messages in
3765 as well as a possibly tracked line editor history file.
3771 but open the mailbox readonly.
3775 (fi) The file command switches to a new mailbox.
3776 Without arguments it shows status information of the current mailbox.
3777 If an argument is given, it will write out changes (such as deletions)
3778 the user has made and open a new mailbox.
3781 .Sx "filename transformations"
3782 are recognized for the
3784 argument, as documented in the introduction of
3788 If the name ends with
3793 it is treated as being compressed with
3798 respectively, and transparently handled through an intermediate
3799 (un)compression step (using a temporary file) with the according
3800 facility, sufficient support provided.
3801 Likewise, if the named file does not exist, but a file with one of the
3802 mentioned compression extensions does, then the name is automatically
3803 expanded and the compressed file is used.
3805 Otherwise, if the name ends with an extension for which
3806 .Va file-hook-load-EXTENSION
3808 .Va file-hook-save-EXTENSION
3809 variables are set, then the given hooks will be used to load and save
3811 and \*(UA will work with an intermediate temporary file.
3813 MBOX files (flat file-based mailboxes) are generally locked during file
3814 operations in order to avoid inconsistencies due to concurrent
3816 \*(OPal Mailbox files which \*(UA treats as the system
3821 .Sx "primary system mailbox" Ns
3822 es in general will also be protected by so-called dotlock files, the
3823 traditional way of mail spool file locking: for any file
3827 will be created for the duration of the synchronization \(em
3828 as necessary a privilege-separated dotlock child process will be used
3829 to accommodate for necessary privilege adjustments in order to create
3830 the dotlock file in the same directory
3831 and with the same user and group identities as the file of interest.
3835 refers to a directory with the subdirectories
3840 then it is treated as a folder in
3842 format; \*(ID the variable
3844 can be used to control the format of yet non-existent folders.
3847 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3848 .Dl \*(OU protocol://[user@]host[:port][/path]
3850 is taken as an Internet mailbox specification.
3851 The \*(OPally supported protocols are
3855 (POP3 with SSL/TLS encrypted transport).
3858 part is valid only for IMAP; there it defaults to
3860 Also see the section
3861 .Sx "On URL syntax and credential lookup" .
3865 contains special characters, in particular
3869 they must be escaped in URL notation \(en the command
3871 can be used to show the necessary conversion.
3875 Takes a message list and marks the messages as
3877 ged for urgent/special attention.
3878 This mark has no technical meaning in the mail system;
3879 it just causes messages to be highlighted in the header summary,
3880 and makes them specially addressable.
3889 With no arguments, list the names of the folders in the folder directory.
3890 With an existing folder as an argument,
3891 lists the names of folders below the named folder.
3897 but saves the message in a file named after the local part of the first
3898 recipient's address (instead of in
3905 but saves the message in a file named after the local part of the first
3906 recipient's address (instead of in
3913 but responds to all recipients regardless of the
3918 .It Ic followupsender
3921 but responds to the sender only regardless of the
3937 (f) Takes a list of message specifications and displays a summary of
3938 their message headers, exactly as via
3940 An alias of this command is
3943 .Sx "Specifying messages" .
3949 but saves the message in a file named after the local part of the
3950 recipient's address (instead of in
3955 Takes a message and the address of a recipient
3956 and forwards the message to him.
3957 The text of the original message is included in the new one,
3958 with the value of the
3960 variable preceding it.
3961 To filter the included header fields to the desired subset use the
3963 slot of the white- and blacklisting command
3965 Only the first part of a multipart message is included unless
3966 .Va forward-as-attachment ,
3967 and recipient addresses will be stripped from comments, names etc.
3968 unless the internal variable
3974 \*(OB Superseded by the multiplexer
3979 \*(OB Superseded by the multiplexer
3984 Define or list command aliases, so-called ghosts.
3985 Without arguments a list of all currently known aliases is shown.
3986 With one argument the expansion of the given alias is shown.
3987 With two or more arguments a command alias is defined or updated: the
3988 first argument is the name under which the remaining command line should
3989 be accessible, the content of which can be just about anything.
3990 A ghost can be used everywhere a normal command can be used, but always
3991 takes precedence; any arguments that are given to the command alias are
3992 joined onto the alias content, and the resulting string forms the
3993 command line that is, in effect, executed.
3996 .Bd -literal -offset indent
3998 `ghost': no such alias: "xx"
4001 ghost xx "echo hello,"
4011 \*(NQ Multiplexer command to establish white- and blacklisting
4012 selections of header fields for a variety of applications.
4013 Without any arguments the entire set of known contexts and their current
4014 settings is displayed.
4015 When given arguments, the first argument is the context to which the
4016 command applies, one of (case-insensitively)
4018 for display purposes (via, e.g.,
4021 for selecting which headers shall be stored persistently when
4027 ing messages (note that MIME related etc. header fields should not be
4028 ignored in order to not destroy usability of the message in this case),
4030 for stripping down messages when
4032 ing message (has no effect if
4033 .Va forward-as-attachment
4036 for defining user-defined set of fields for the command
4040 The current settings of the given context are displayed if only the
4041 first argument is given.
4042 A second argument denotes the type of restriction that is to be chosen,
4043 it may be (a case-insensitive prefix of)
4047 for white- and blacklisting purposes, respectively.
4048 Establishing a whitelist suppresses inspection of the corresponding
4050 If no further argument is given the current settings of the given type
4054 With four or more arguments the third denotes the action to be applied,
4059 for addition of fields, and
4063 for removal of fields from the given type of the given context.
4064 The fourth, and any following arguments are expected to specify the
4065 fields of desire, or \*(OPally, regular expression matches ought to
4067 The special wildcard field (asterisk,
4069 will establish a (fast) shorthand setting which covers all fields, or
4070 remove all fields in one operation, respectively.
4075 (h) Show the current group of headers, the size of which depends on
4078 and the style of which can be adjusted with the variable
4080 If a message-specification is given the group of headers containing the
4081 first message therein is shown and the message at the top of the screen
4096 the list of history entries;
4099 argument selects and shows the respective history entry \(en
4102 to accept it, and the history entry will become the new history top.
4103 The default mode if no arguments are given is
4110 Takes a message list and marks each message therein to be saved in the
4115 Does not override the
4118 \*(UA deviates from the POSIX standard with this command, because a
4120 command issued after
4122 will display the following message, not the current one.
4127 (i) Part of the nestable
4128 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
4129 conditional execution construct \(em if the given condition is true then
4130 the encapsulated block is executed.
4131 POSIX only supports the (case-insensitive) conditions
4136 end, all remaining conditions are non-portable extensions; note that
4137 falsely specified conditions cause the execution of the entire
4138 conditional construct until the (matching) closing
4140 command to be suppressed.
4141 The syntax of the nestable
4143 conditional execution construct requires that each condition and syntax
4144 element is surrounded by whitespace.
4146 .Bd -literal -offset indent
4155 The (case-insensitive) condition
4157 erminal will evaluate to true if the standard input is a terminal, i.e.,
4158 in interactive sessions.
4159 Another condition can be any boolean value (see the section
4160 .Sx "INTERNAL VARIABLES"
4161 for textual boolean representations) to mark an enwrapped block as
4164 .Dq always execute .
4165 It is possible to check
4166 .Sx "INTERNAL VARIABLES"
4169 variables for existence or compare their expansion against a user given
4170 value or another variable by using the
4172 .Pf ( Dq variable next )
4173 conditional trigger character;
4174 a variable on the right hand side may be signalled using the same
4176 The variable names may be enclosed in a pair of matching braces.
4179 The available comparison operators are
4183 (less than or equal to),
4189 (greater than or equal to),
4193 (is substring of) and
4195 (is not substring of).
4196 The values of the left and right hand side are treated as strings and
4197 are compared 8-bit byte-wise, ignoring case according to the rules of
4198 the US-ASCII encoding (therefore, dependent on the active locale,
4199 possibly producing false results for strings in the locale encoding).
4200 Except for the substring checks the comparison will instead be performed
4201 arithmetically if both, the user given value as well as the variable
4202 content, can be parsed as numbers (integers).
4203 An unset variable is treated as the empty string.
4206 When the \*(OPal regular expression support is available, the additional
4212 They treat the right hand side as an extended regular expression that is
4213 matched case-insensitively and according to the active
4215 locale, meaning that strings in the locale encoding should be matched
4219 Conditions can be joined via AND-OR lists (where the AND operator is
4221 and the OR operator is
4223 which have equal precedence and will be evaluated with left
4224 associativity, thus using the same syntax that is known for the
4226 It is also possible to form groups of conditions and lists by enclosing
4227 them in pairs of brackets
4228 .Ql [\ \&.\&.\&.\ ] ,
4229 which may be interlocked within each other, and also be joined via
4233 The results of individual conditions and entire groups may be modified
4234 via unary operators: the unary operator
4236 will reverse the result.
4238 .Bd -literal -offset indent
4242 if $ttycharset == "UTF-8"
4243 echo *ttycharset* is set to UTF-8, case-insensitively
4247 echo These two variables are equal
4249 if $version-major >= 15
4250 echo Running a new version..
4251 if $features =@ +regex
4252 if $TERM =~ "^xterm\&.*"
4253 echo ..in an X terminal
4256 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
4259 if true && $debug || ${verbose}
4260 echo Left associativity, as is known from the shell
4262 if ! ! true && ! [ ! $debug && ! $verbose ]
4263 echo Unary operator support
4273 Superseded by the multiplexer
4278 Shows the names of all available commands, alphabetically sorted.
4279 If given any non-whitespace argument the list will be shown in the order
4280 in which command prefixes are searched.
4283 output is available.
4287 This command can be used to localize changes to variables, meaning that
4288 their state will be reverted to the former one once the covered scope
4290 It can only be used inside of macro definition blocks introduced by
4294 and is interpreted as a boolean (string, see
4295 .Sx "INTERNAL VARIABLES" ) ;
4298 of an account is left once it is switched off again.
4299 .Bd -literal -offset indent
4300 define temporary_settings {
4315 enables change localization and calls
4317 which explicitly resets localization, then any value changes within
4319 will still be reverted by
4321 \*(ID Once the outermost level, the one which enabled localization
4322 first, is left, but no earlier, all adjustments will be unrolled.
4323 \*(ID Likewise worth knowing, if in this example
4325 changes to a different
4327 which sets some variables that are yet covered by localizations, their
4328 scope will be extended, and in fact leaving the
4330 will (thus) restore settings in (likely) global scope which actually
4331 were defined in a local, private context.
4335 Reply to messages that come in via known
4338 .Pf ( Ic mlsubscribe )
4339 mailing lists, or pretend to do so (see
4340 .Sx "Mailing lists" ) :
4343 functionality this will actively resort and even remove message
4344 recipients in order to generate a message that is supposed to be sent to
4346 For example it will also implicitly generate a
4347 .Ql Mail-Followup-To:
4348 header if that seems useful, regardless of the setting of the variable
4355 but saves the message in a file named after the local part of the first
4356 recipient's address (instead of in
4361 (m) Takes a (list of) recipient address(es) as (an) argument(s),
4362 or asks on standard input if none were given;
4363 then collects the remaining mail content and sends it out.
4367 (mb) The given message list is to be sent to
4369 when \*(UA is quit; this is the default action unless the variable
4372 \*(ID This command can only be used in a
4374 .Sx "primary system mailbox" .
4378 Without any arguments the content of the MIME type cache will displayed.
4379 Otherwise each argument defines a complete MIME type specification of
4380 a type that shall be added (prepended) to the cache.
4381 In any event MIME type sources are loaded first as necessary \(en
4382 .Va mimetypes-load-control
4383 can be used to fine-tune which sources are actually loaded.
4384 Refer to the section on
4385 .Sx "The mime.types files"
4386 for more on MIME type specifications and this topic in general.
4387 MIME type unregistration and cache resets can be triggered with
4392 Without arguments the list of all currently defined mailing lists
4393 (and their attributes, if any) is shown; a more verbose listing will be
4394 produced if either of
4399 Otherwise all given arguments (which need not be quoted except for
4400 whitespace) will be added and henceforth be recognized as mailing lists.
4401 Mailing lists may be removed via the command
4404 If the \*(OPal regular expression support is available then mailing
4405 lists may also be specified as (extended) regular expressions (see
4411 Without arguments the list of all currently defined mailing lists which
4412 have a subscription attribute is shown; a more verbose listing will be
4413 produced if either of
4418 Otherwise this attribute will be set for all given mailing lists,
4419 newly creating them as necessary (as via
4421 Subscription attributes may be removed via the command
4430 but moves the messages to a file named after the local part of the
4431 sender address of the first message (instead of in
4438 but marks the messages for deletion if they were transferred
4445 but also displays header fields which would not pass the
4447 selection, and all MIME parts.
4455 on the given messages, even in non-interactive mode and as long as the
4456 standard output is a terminal.
4462 \*(OP When used without arguments or if
4464 has been given the content of the
4466 cache is shown, loading it first as necessary.
4469 then the cache will only be initialized and
4471 will remove its contents.
4472 Note that \*(UA will try to load the file only once, use
4473 .Ql Ic \&\&netrc Ns \:\0\:clear
4474 to unlock further attempts.
4479 .Sx "On URL syntax and credential lookup" ;
4481 .Sx "The .netrc file"
4482 documents the file format in detail.
4486 Checks for new mail in the current folder without committing any changes
4488 If new mail is present, a message is shown.
4492 the headers of each new message are also shown.
4493 This command is not available for all mailbox types.
4501 Goes to the next message in sequence and types it.
4502 With an argument list, types the next matching message.
4516 If the current folder is accessed via a network connection, a
4518 command is sent, otherwise no operation is performed.
4524 but also displays header fields which would not pass the
4526 selection, and all MIME parts.
4534 on the given messages, even in non-interactive mode and as long as the
4535 standard output is a terminal.
4543 but also pipes header fields which would not pass the
4545 selection, and all parts of MIME
4546 .Ql multipart/alternative
4551 (pi) Takes a message list and a shell command
4552 and pipes the messages through the command.
4553 Without an argument the current message is piped through the command
4560 every message is followed by a formfeed character.
4581 (q) Terminates the session, saving all undeleted, unsaved messages in
4584 preserving all messages marked with
4588 or never referenced in the system
4590 and removing all other messages from the
4592 .Sx "primary system mailbox" .
4593 If new mail has arrived during the session,
4595 .Dq You have new mail
4597 If given while editing a mailbox file with the command line flag
4599 then the edit file is rewritten.
4600 A return to the shell is effected,
4601 unless the rewrite of edit file fails,
4602 in which case the user can escape with the exit command.
4606 \*(NQ Read a line from standard input, and assign the splitted and
4607 trimmed line data to the given variables.
4608 If there are more fields than variables, assign successive fields to the
4609 last given variable.
4610 If there are less fields than variables, assign the empty string to the
4612 \*(ID This command will likely be extended towards more
4614 compatibility: for now splitting always occurs at whitespace, reverse
4615 solidus newline escaping is always supported, and the \*(OPal line
4616 editing features are always available when on an interactive terminal.
4617 .Bd -literal -offset indent
4620 ? echo "<$a> <$b> <$c>"
4636 Removes the named files or directories.
4637 If a name refer to a mailbox, e.g., a Maildir mailbox, then a mailbox
4638 type specific removal will be performed, deleting the complete mailbox.
4639 The user is asked for confirmation in interactive mode.
4643 Takes the name of an existing folder
4644 and the name for the new folder
4645 and renames the first to the second one.
4646 Both folders must be of the same type.
4650 (R) Reply to originator.
4651 Does not reply to other recipients of the original message.
4653 will exchange this command with
4655 Unless the internal variable
4657 is set the recipient address will be stripped from comments, names etc.
4661 (r) Take a message and group-responds to it by addressing the sender
4664 .Va followup-to-honour ,
4667 .Va recipients-in-cc
4668 influence response behaviour.
4671 offers special support for replying to mailing lists.
4672 Unless the internal variable
4674 is set recipient addresses will be stripped from comments, names etc.
4687 but initiates a group-reply regardless of the value of
4694 but responds to the sender only regardless of the value of
4701 but does not add any header lines.
4702 This is not a way to hide the sender's identity,
4703 but useful for sending a message again to the same recipients.
4707 Takes a list of messages and a user name
4708 and sends each message to the named user.
4710 and related header fields are prepended to the new copy of the message.
4728 .It Ic respondsender
4734 (ret) Superseded by the multiplexer
4741 but saves the messages in a file named after the local part of the
4742 sender of the first message instead of (in
4744 and) taking a filename argument.
4748 (s) Takes a message list and a filename and appends each message in turn
4749 to the end of the file.
4750 If no filename is given, the
4753 The filename in quotes, followed by the generated character count
4754 is echoed on the user's terminal.
4757 .Sx "primary system mailbox"
4758 the messages are marked for deletion.
4761 .Sx "filename transformations"
4762 are recognized, as documented in the introduction of
4767 \*(OB Superseded by the multiplexer
4772 \*(OB Superseded by the multiplexer
4777 \*(OB Superseded by the multiplexer
4782 Takes a message specification (list) and displays a header summary of
4783 all matching messages, as via
4785 This command is an alias of
4788 .Sx "Specifying messages" .
4792 Takes a message list and marks all messages as having been read.
4796 (se) Without arguments this command shows all internal variables which
4797 are currently known to \*(UA (they have been set).
4798 A more verbose listing will be produced if either of
4802 are set, in which case variables may be preceded with a comment line
4803 that gives some context of what \*(UA knows about the given variable.
4805 Otherwise the given variables (and arguments) are set or adjusted.
4806 Arguments are of the form
4808 (no space before or after
4812 if there is no value, i.e., a boolean variable.
4813 Quotation marks may be placed around any part of the assignment
4814 statement to quote blanks or tabs, e.g.,
4816 .Dl set indentprefix='->'
4818 If an argument begins with
4822 the effect is the same as invoking the
4824 command with the remaining part of the variable
4825 .Pf ( Ql unset save ) .
4829 that is known to map to an environment variable will automatically cause
4830 updates in the program environment (unsetting a variable in the
4831 environment requires corresponding system support).
4832 Please use the command
4834 for further environmental control.
4839 .Sx "INTERNAL VARIABLES"
4845 (sh) Invokes an interactive version of the shell.
4849 Without arguments the list of all currently defined shortcuts is
4851 Otherwise all given arguments (which need not be quoted except for
4852 whitespace) are treated as pairs of shortcuts and their expansions,
4853 creating new or changing already existing shortcuts, as necessary.
4854 Shortcuts may be removed via the command
4861 but performs neither MIME decoding nor decryption, so that the raw
4862 message text is shown.
4866 (si) Shows the size in characters of each message of the given
4871 Shows the current sorting criterion when used without an argument.
4872 Otherwise creates a sorted representation of the current folder,
4875 command and the addressing modes such that they refer to messages in
4877 Message numbers are the same as in regular mode.
4881 a header summary in the new order is also displayed.
4882 Automatic folder sorting can be enabled by setting the
4884 variable, as in, e.g.,
4885 .Ql set autosort=thread .
4886 Possible sorting criterions are:
4888 .Bl -tag -compact -width "subject"
4890 Sort the messages by their
4892 field, that is by the time they were sent.
4894 Sort messages by the value of their
4896 field, that is by the address of the sender.
4899 variable is set, the sender's real name (if any) is used.
4901 Sort the messages by their size.
4903 \*(OP Sort the message by their spam score, as has been classified by
4906 Sort the messages by their message status.
4908 Sort the messages by their subject.
4910 Create a threaded display.
4912 Sort messages by the value of their
4914 field, that is by the address of the recipient.
4917 variable is set, the recipient's real name (if any) is used.
4922 (so) The source command reads commands from the given file, which is
4923 subject to the usual filename expansions (see introductional words of
4925 If the given argument ends with a vertical bar
4927 then the argument will instead be interpreted as a shell command and
4928 \*(UA will read the output generated by it.
4929 Interpretation of commands read is stopped when an error is encountered.
4932 cannot be used from within macros that execute as
4933 .Va folder-hook Ns s
4936 i.e., it can only be called from macros that were
4943 (beside not supporting pipe syntax aka shell command input) is that
4944 this command will not generate an error if the given file argument
4945 cannot be opened successfully.
4949 \*(OP Takes a list of messages and clears their
4955 \*(OP Takes a list of messages and causes the
4957 to forget it has ever used them to train its Bayesian filter.
4958 Unless otherwise noted the
4960 flag of the message is inspected to chose whether a message shall be
4968 \*(OP Takes a list of messages and informs the Bayesian filter of the
4972 This also clears the
4974 flag of the messages in question.
4978 \*(OP Takes a list of messages and rates them using the configured
4979 .Va spam-interface ,
4980 without modifying the messages, but setting their
4982 flag as appropriate; because the spam rating headers are lost the rate
4983 will be forgotten once the mailbox is left.
4984 Refer to the manual section
4986 for the complete picture of spam handling in \*(UA.
4990 \*(OP Takes a list of messages and sets their
4996 \*(OP Takes a list of messages and informs the Bayesian filter of the
5002 flag of the messages in question.
5011 Create a threaded representation of the current folder,
5012 i.\|e. indent messages that are replies to other messages in the header
5013 display and change the
5015 command and the addressing modes such that they refer to messages in the
5017 Message numbers are the same as in unthreaded mode.
5021 a header summary in threaded order is also displayed.
5030 slot for white- and blacklisting header fields.
5034 (to) Takes a message list and types out the first
5036 lines of each message on the users' terminal.
5037 Unless a special selection has been established for the
5041 command, the only header fields that are displayed are
5052 It is possible to apply compression to what is displayed by setting
5054 Messages are decrypted and converted to the terminal character set
5059 (tou) Takes a message list and marks the messages for saving in
5061 \*(UA deviates from the POSIX standard with this command,
5064 command will display the following message instead of the current one.
5070 but also displays header fields which would not pass the
5072 selection, and all parts of MIME
5073 .Ql multipart/alternative
5078 (t) Takes a message list and types out each message on the users'
5082 For MIME multipart messages, all parts with a content type of
5086 are shown, the other are hidden except for their headers.
5087 Messages are decrypted and converted to the terminal character set
5092 Delete all given accounts.
5093 An error message is shown if a given account is not defined.
5096 will discard all existing accounts.
5100 (una) Takes a list of names defined by alias commands
5101 and discards the remembered groups of users.
5104 will discard all existing aliases.
5108 Takes a message list and marks each message as not having been answered.
5114 ing, specified by its context and input sequence, both of which may be
5115 specified as a wildcard (asterisk,
5119 will remove all bindings of all contexts.
5123 Only applicable to threaded mode.
5124 Takes a message list and makes the message and all replies to it visible
5125 in header summaries again.
5126 When a message becomes the current message,
5127 it is automatically made visible.
5128 Also when a message with collapsed replies is displayed,
5129 all of these are automatically uncollapsed.
5135 mapping for the given colour type (see
5137 for a list of types) and mapping; if the optional precondition argument
5138 is used then only the exact tuple of mapping and precondition is removed.
5141 will remove all mappings (no precondition allowed).
5143 .Sx "Coloured display"
5144 for the general picture.
5148 Undefine all given macros.
5149 An error message is shown if a given macro is not defined.
5152 will discard all existing macros.
5156 (u) Takes a message list and marks each message as not being deleted.
5160 Takes a message list and
5166 Takes a message list and marks each message as not being
5171 \*(OB Superseded by the multiplexer
5176 \*(OB Superseded by the multiplexer
5181 Remove all the given command
5185 will remove all ghosts.
5189 Superseded by the multiplexer
5194 Delete all given MIME types, e.g.,
5195 .Ql unmimetype text/plain
5196 will remove all registered specifications for the MIME type
5200 will discard all existing MIME types, just as will
5202 but which also reenables cache initialization via
5203 .Va mimetypes-load-control .
5207 Forget about all the given mailing lists.
5210 will remove all lists.
5215 .It Ic unmlsubscribe
5216 Remove the subscription attribute from all given mailing lists.
5219 will clear the attribute from all lists which have it set.
5230 Takes a message list and marks each message as not having been read.
5234 Superseded by the multiplexer
5239 \*(OB Superseded by the multiplexer
5244 \*(OB Superseded by the multiplexer
5249 (uns) Takes a list of internal variable names and discards their
5250 remembered values; the reverse of
5257 Deletes the shortcut names given as arguments.
5260 will remove all shortcuts.
5264 Disable sorted or threaded mode
5270 return to normal message order and,
5274 displays a header summary.
5284 Perform URL percent codec operations, rather according to RFC 3986,
5285 on all given strings.
5286 This is character set agnostic and thus locale dependent, and it may
5287 decode bytes which are invalid in the current locale, unless the input
5288 solely consists of characters in the portable character set, see
5289 .Sx "Character sets" .
5290 The first argument specifies the operation:
5294 perform plain URL percent en- and decoding, respectively.
5298 perform a slightly modified operation which should be better for
5299 pathnames: it does not allow a tilde
5301 and will neither accept hyphen
5305 as an initial character.
5309 Edit the values of or create the given variable(s) in the
5311 Boolean variables cannot be edited.
5315 This command produces the same output as the listing mode of
5319 ity adjustments, but only for the given variables.
5323 \*(OP Takes a message list and verifies each message.
5324 If a message is not a S/MIME signed message,
5325 verification will fail for it.
5326 The verification process checks if the message was signed using a valid
5328 if the message sender's email address matches one of those contained
5329 within the certificate,
5330 and if the message content has been altered.
5342 (v) Takes a message list and invokes the display editor on each message.
5343 Modified contents are discarded unless the
5349 (w) For conventional messages the body without all headers is written.
5350 The original message is never marked for deletion in the originating
5352 The output is decrypted and converted to its native format as necessary.
5353 If the output file exists, the text is appended.
5354 If a message is in MIME multipart format its first part is written to
5355 the specified file as for conventional messages, handling of the remains
5356 depends on the execution mode.
5357 No special handling of compressed files is performed.
5359 In interactive mode the user is consecutively asked for the filenames of
5360 the processed parts.
5361 For convience saving of each part may be skipped by giving an empty
5362 value, the same result as writing it to
5364 Shell piping the part content by specifying a leading vertical bar
5366 character for the filename is supported.
5367 Other user input is expanded as usually for folders, e.g., tilde
5368 expansion is performed, and contents of the destination file are
5369 overwritten if the file previously existed.
5371 \*(ID In non-interactive mode any part which does not specify a filename
5372 is ignored, and suspicious parts of filenames of the remaining parts are
5373 URL percent encoded (as via
5375 to prevent injection of malicious character sequences, resulting in
5376 a filename that will be written into the current directory.
5377 Existing files will not be overwritten, instead the part number or
5378 a dot are appended after a number sign
5380 to the name until file creation succeeds (or fails due to other
5390 \*(UA presents message headers in
5392 fuls as described under the
5395 Without arguments this command scrolls to the next window of messages,
5396 likewise if the argument is
5400 scrolls to the last,
5402 scrolls to the first, and
5407 A number argument prefixed by
5411 indicates that the window is calculated in relation to the current
5412 position, and a number without a prefix specifies an absolute position.
5418 but scrolls to the next or previous window that contains at least one
5427 .\" .Sh COMMAND ESCAPES {{{
5428 .Sh "COMMAND ESCAPES"
5430 Here is a summary of the command escapes available in compose mode,
5431 which are used to perform special functions when composing messages.
5432 Command escapes are only recognized at the beginning of lines.
5433 The actual escape character can be set via the internal variable
5435 it defaults to the tilde
5439 .Bl -tag -width ".It Ic BaNg"
5442 Insert the string of text in the message prefaced by a single
5444 (If the escape character has been changed,
5445 that character must be doubled
5446 in order to send it at the beginning of a line.)
5449 .It Ic ~! Ar command
5450 Execute the indicated shell
5452 which follows, replacing unescaped exclamation marks with the previously
5453 executed command if the internal variable
5455 is set, then return to the message.
5459 Same effect as typing the end-of-file character.
5462 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
5463 Execute the given \*(UA command.
5464 Not all commands, however, are allowed.
5468 Write a summary of command escapes.
5471 .It Ic ~< Ar filename
5476 .It Ic ~<! Ar command
5478 is executed using the shell.
5479 Its standard output is inserted into the message.
5482 .It Ic ~@ Op Ar filename...
5483 Append or edit the list of attachments.
5486 arguments are specified they are treated as a
5490 token-separating commas are ignored) list of filenames, to be
5491 interpreted as documented for the command line option
5493 with the message number exception as below.
5496 arguments the attachment list is edited, entry by entry;
5497 if a filename is left empty, that attachment is deleted from the list;
5498 once the end of the list is reached either new attachments may be
5499 entered or the session can be quit by committing an empty
5502 For each mode, if a given file name solely consists of the number sign
5504 followed by a valid message number of the currently active mailbox, then
5505 the given message is attached as a MIME
5507 part (note the number sign is the comment character and must be quoted).
5511 Inserts the string contained in the
5514 .Ql Ic ~i Ns \0Sign ) .
5519 ting the variable(s) instead!) The escape sequences tabulator
5527 Inserts the string contained in the
5530 .Ql Ic ~i Ns \0sign ) .
5535 ting the variable(s) instead!) The escape sequences tabulator
5542 .It Ic ~b Ar name ...
5543 Add the given names to the list of blind carbon copy recipients.
5546 .It Ic ~c Ar name ...
5547 Add the given names to the list of carbon copy recipients.
5551 Read the file specified by the
5553 variable into the message.
5557 Invoke the text editor on the message collected so far.
5558 After the editing session is finished,
5559 the user may continue appending text to the message.
5562 .It Ic ~F Ar messages
5563 Read the named messages into the message being sent, including all
5564 message headers and MIME parts.
5565 If no messages are specified, read in the current message.
5568 .It Ic ~f Ar messages
5569 Read the named messages into the message being sent.
5570 If no messages are specified, read in the current message.
5571 Strips down the list of header fields according to the
5573 white- and blacklist selection of
5575 For MIME multipart messages,
5576 only the first displayable part is included.
5580 Edit the message header fields
5585 by typing each one in turn and allowing the user to edit the field.
5586 The default values for these fields originate from the
5594 Edit the message header fields
5600 by typing each one in turn and allowing the user to edit the field.
5603 .It Ic ~i Ar variable
5604 Insert the value of the specified variable into the message,
5605 adding a newline character at the end.
5606 The message remains unaltered if the variable is unset or empty.
5611 ting the variable(s) instead!) The escape sequences tabulator
5618 .It Ic ~M Ar messages
5619 Read the named messages into the message being sent,
5622 If no messages are specified, read the current message.
5625 .It Ic ~m Ar messages
5626 Read the named messages into the message being sent,
5629 If no messages are specified, read the current message.
5630 Strips down the list of header fields according to the
5632 white- and blacklist selection of
5634 For MIME multipart messages,
5635 only the first displayable part is included.
5639 Display the message collected so far,
5640 prefaced by the message header fields
5641 and followed by the attachment list, if any.
5645 Abort the message being sent,
5646 copying it to the file specified by the
5653 .It Ic ~R Ar filename
5654 Read the named file into the message, indented by
5658 .It Ic ~r Ar filename
5659 Read the named file into the message.
5663 Cause the named string to become the current subject field.
5664 Newline (NL) and carriage-return (CR) bytes are invalid and will be
5665 normalized to space (SP) characters.
5668 .It Ic ~t Ar name ...
5669 Add the given name(s) to the direct recipient list.
5672 .It Ic ~U Ar messages
5673 Read in the given / current message(s) excluding all headers, indented by
5677 .It Ic ~u Ar messages
5678 Read in the given / current message(s), excluding all headers.
5682 Invoke an alternate editor (defined by the
5684 environment variable) on the message collected so far.
5685 Usually, the alternate editor will be a screen editor.
5686 After the editor is quit,
5687 the user may resume appending text to the end of the message.
5690 .It Ic ~w Ar filename
5691 Write the message onto the named file.
5693 the message is appended to it.
5699 except that the message is not saved at all.
5702 .It Ic ~| Ar command
5703 Pipe the message through the specified filter command.
5704 If the command gives no output or terminates abnormally,
5705 retain the original text of the message.
5708 is often used as a rejustifying filter.
5712 .It Ic ~^ Ar cmd Op Ar subcmd Op Ar arg3 Op Ar arg4
5713 Low-level command ment for scripted message access, i.e., for
5714 .Va on-compose-done-shell
5716 .Va on-compose-done .
5717 The used protocol is likely subject to changes, and therefore the
5718 mentioned hooks receive the used protocol version as an initial line.
5719 In general the first field of a response line represents a status code
5720 which specifies whether a command was successful or not, whether result
5721 data is to be expected, and if, the format of the result data.
5722 The status codes are:
5725 .Bl -tag -compact -width _210_
5727 Status ok; the remains of the line are the result.
5729 Status ok; the rest of the line is optionally used for more status.
5730 What follows are lines of result addresses, terminated by an empty line.
5731 The address lines consist of two fields, the first of which is the
5732 plain address, e.g.,
5734 separated by a single ASCII SP space from the second which contains the
5735 unstripped address, even if that is identical to the first field, e.g.,
5736 .Ql (Lovely) Bob <bob@exam.ple> .
5738 Status ok; the rest of the line is optionally used for more status.
5739 What follows are lines of furtherly unspecified string content,
5740 terminated by an empty line.
5742 Syntax error; invalid command.
5744 Syntax error in parameters or arguments.
5746 Error: an argument fails verification.
5747 For example an invalid address has been specified.
5749 Error: an otherwise valid argument is rendered invalid due to context.
5750 For example, a second address is added to a header which may consist of
5751 a single address only.
5755 If a command indicates failure then the message will have remained
5757 Most commands can fail with
5759 if required arguments are missing (false command usage).
5760 The following commands are supported, and, as usual, case-insensitive:
5763 .Bl -hang -width header
5765 This command allows listing, inspection, and editing of message headers.
5766 The second argument specifies the subcommand to apply, one of:
5769 .Bl -hang -compact -width remove
5771 Without a third argument a list of all yet existing headers is given via
5773 this command is the default command of
5775 if no second argument has been given.
5776 A third argument restricts output to the given header only, which may
5779 if no such field is defined.
5782 Shows the content of the header given as the third argument.
5783 Dependent on the header type this may respond with
5787 any failure results in
5791 This will remove all instances of the header given as the third
5796 if no such header can be found.
5799 Create a new or an additional instance of the header given in the third
5800 argument, with the header body content as given in the fourth argument
5801 (the remains of the line).
5804 if the third argument specifies a free-form header field name that is
5805 invalid, or if body content extraction fails to succeed,
5807 if any extracted address does not pass syntax and/or security checks, and
5809 to indicate prevention of excessing a single-instance header \(em note that
5811 can be appended to (a space separator will be added automatically first).
5813 is returned upon success.
5818 This command allows listing, removal and addition of message attachments.
5819 The second argument specifies the subcommand to apply, one of:
5822 .Bl -hang -compact -width remove
5824 List all attachments via
5828 if no attachments exist.
5829 This command is the default command of
5831 if no second argument has been given.
5834 This will remove the attachment given as the third argument, and report
5838 if no such attachment can be found.
5839 If there exists any path component in the given argument, then an exact
5840 match of the path which has been used to create the attachment is used
5841 directly, but if only the basename of that path matches then all
5842 attachments are traversed to find an exact match first, and the removal
5843 occurs afterwards; if multiple basenames match, a
5846 Message attachments are treated as absolute pathnames.
5848 If no path component exists in the given argument, then all attachments
5849 will be searched for
5851 parameter matches as well as for matches of the basename of the path
5852 which has been used when the attachment has been created; multiple
5857 This will interpret the third argument as a number and remove the
5858 attachment at that list position (counting from one!), reporting
5862 if the argument is not a number or
5864 if no such attachment exists.
5867 Adds the attachment given as the third argument, specified exactly as
5868 documented for the command line flag
5870 and supporting the message number extension as documented for
5874 upon success, with the index of the new attachment following,
5876 if the given file cannot be opened,
5878 if an on-the-fly performed character set conversion fails, otherwise
5880 is reported; this is also reported if character-set conversion is
5881 requested but not available.
5884 This uses the same search mechanism as described for
5886 and prints any known attributes of the first found attachment via
5890 if no such attachment can be found.
5891 The attributes are written as lines of keyword and value tuples, the
5892 keyword being separated from the rest of the line with an ASCII SP space
5896 This uses the same search mechanism as described for
5898 and is otherwise identical to
5901 .It Ar attribute-set
5902 This uses the same search mechanism as described for
5904 and will assign the attribute given as the fourth argument, which is
5905 expected to be a value tuple of keyword and other data, separated by
5906 a ASCII SP space or TAB tabulator character.
5907 If the value part is empty, then the given attribute is removed, or
5908 reset to a default value if existence of the attribute is crucial.
5911 upon success, with the index of the found attachment following,
5913 for message attachments or if the given keyword is invalid, and
5915 if no such attachment can be found.
5916 The following keywords may be used (case-insensitively):
5918 .Bl -hang -compact -width ".Ql filename"
5920 Sets the filename of the MIME part, i.e., the name that is used for
5921 display and when (suggesting a name for) saving (purposes).
5922 .It Ql content-description
5923 Associate some descriptive information to the attachment's content, used
5924 in favour of the plain filename by some MUAs.
5926 May be used for uniquely identifying MIME entities in several contexts;
5927 this expects a special reference address format as defined in RFC 2045
5930 upon address content verification failure.
5932 Specifies the media type and subtype of the part; managed automatically.
5933 .It Ql content-disposition
5934 Automatically set to the string
5938 .It Ar attribute-set-at
5939 This uses the same search mechanism as described for
5941 and is otherwise identical to
5951 .\" .Sh INTERNAL VARIABLES {{{
5952 .Sh "INTERNAL VARIABLES"
5954 Internal \*(UA variables are controlled via the
5958 commands; prefixing a variable name with the string
5962 has the same effect as using
5968 Creation or editing of variables can be performed in the
5973 will give more insight on the given variable(s), and
5975 when called without arguments, will show a listing of all variables.
5976 Both commands support a more
5979 Some well-known variables will also become inherited from the
5982 implicitly, others can be explicitly imported with the command
5984 and henceforth share the said properties.
5987 Two different kind of internal variables exist.
5988 There are boolean variables, which can only be in one of the two states
5992 and value variables with a(n optional) string value.
5993 For the latter proper quoting is necessary upon assignment time, the
5994 introduction of the section
5996 documents the supported quoting rules.
5998 .Bd -literal -offset indent
5999 wysh set one=val\e 1 two="val 2" \e
6000 three='val "3"' four=$'val \e'4\e''
6001 varshow one two three four
6002 unset one two three four
6006 Dependent upon the actual option the string values will be interpreted
6007 as numbers, colour names, normal text etc., but there also exists
6008 a special kind of string value, the
6009 .Dq boolean string ,
6010 which must either be a decimal integer (in which case
6014 and any other value is true) or any of the (case-insensitive) strings
6020 for a false boolean and
6026 for a true boolean; a special kind of boolean string is the
6028 which is a boolean string that can optionally be prefixed with the
6029 (case-insensitive) term
6033 which causes prompting of the user in interactive mode, with the given
6034 boolean as the default value.
6036 .\" .Ss "Initial settings" {{{
6037 .\" (Keep in SYNC: ./nail.h:okeys, ./nail.rc, ./nail.1:"Initial settings")
6038 .Ss "Initial Settings"
6040 The standard POSIX 2008/Cor 2-2016 mandates the following initial
6046 .Pf no Va autoprint ,
6060 .Pf no Va ignoreeof ,
6062 .Pf no Va keepsave ,
6064 .Pf no Va outfolder ,
6072 .Pf no Va sendwait ,
6081 Notes: \*(UA does not support the
6083 variable \(en use command line options or
6085 to pass options through to a
6087 And the default global
6089 file (which is loaded unless the
6091 command line flag has been used or the
6092 .Ev NAIL_NO_SYSTEM_RC
6093 environment variable is set) bends those initial settings a bit, e.g.,
6094 it sets the variables
6099 to name a few, establishes a default
6101 selection etc., and should thus be taken into account.
6104 .\" .Ss "Variables" {{{
6107 .Bl -tag -width ".It Va BaNg"
6109 .It Va -account-name
6110 \*(RO Is set to the active
6115 \*(RO The status of the last command.
6118 .It Va -folder-resolved
6119 \*(RO Set to the fully resolved path of
6121 once that evaluation has occurred; rather internal.
6124 .It Va -mailbox-display
6125 \*(RO The name of the current mailbox
6127 possibly abbreviated for display purposes.
6130 .It Va -mailbox-resolved
6131 \*(RO The fully resolved path of the current mailbox.
6134 .It Va add-file-recipients
6135 \*(BO When file or pipe recipients have been specified,
6136 mention them in the corresponding address fields of the message instead
6137 of silently stripping them from their recipient list.
6138 By default such addressees are not mentioned.
6142 \*(BO Causes only the local part to be evaluated
6143 when comparing addresses.
6147 \*(BO Causes messages saved in
6149 to be appended to the end rather than prepended.
6150 This should always be set.
6154 \*(BO Causes \*(UA to prompt for the subject of each message sent.
6155 If the user responds with simply a newline,
6156 no subject field will be sent.
6160 \*(BO Causes the prompts for
6164 lists to appear after the message has been edited.
6168 \*(BO If set, \*(UA asks for files to attach at the end of each message,
6169 shall the list be found empty at that time.
6170 An empty line finalizes the list.
6174 \*(BO Causes the user to be prompted for carbon copy recipients
6175 (at the end of each message if
6179 are set) shall the list be found empty (at that time).
6180 An empty line finalizes the list.
6184 \*(BO Causes the user to be prompted for blind carbon copy
6185 recipients (at the end of each message if
6189 are set) shall the list be found empty (at that time).
6190 An empty line finalizes the list.
6194 \*(BO\*(OP Causes the user to be prompted if the message is to be
6195 signed at the end of each message.
6198 variable is ignored when this variable is set.
6202 \*(BO Alternative name for
6207 A sequence of characters to display in the
6211 as shown in the display of
6213 each for one type of messages (see
6214 .Sx "Message states" ) ,
6215 with the default being
6218 .Ql NU\ \ *HMFAT+\-$~
6221 variable is set, in the following order:
6223 .Bl -tag -compact -width ".It Ql _"
6245 start of a collapsed thread.
6247 an uncollapsed thread (TODO ignored for now).
6251 classified as possible spam.
6257 Specifies a list of recipients to which a blind carbon copy of each
6258 outgoing message will be sent automatically.
6262 Specifies a list of recipients to which a carbon copy of each outgoing
6263 message will be sent automatically.
6267 \*(BO Causes threads to be collapsed automatically when threaded mode
6274 \*(BO Causes the delete command to behave like
6276 thus, after deleting a message the next one will be typed automatically.
6280 \*(BO\*(OB Causes threaded mode (see the
6282 command) to be entered automatically when a folder is opened.
6284 .Ql autosort=thread .
6288 Causes sorted mode (see the
6290 command) to be entered automatically with the value of this variable as
6291 sorting method when a folder is opened, e.g.,
6292 .Ql set autosort=thread .
6296 \*(BO Enables the substitution of all not (reverse-solidus) escaped
6299 characters by the contents of the last executed command for the
6301 shell escape command and
6303 one of the compose mode
6304 .Sx "COMMAND ESCAPES" .
6305 If this variable is not set no reverse solidus stripping is performed.
6308 .It Va batch-exit-on-error
6309 \*(BO If the batch mode has been enabled via the
6311 command line option, then this variable will be consulted whenever \*(UA
6312 completes one operation (returns to the command prompt); if it is set
6313 then \*(UA will terminate if the last operation generated an error.
6317 \*(OP Terminals generate multi-byte sequences for certain forms of
6318 input, for example for function and other special keys.
6319 Some terminals however do not write these multi-byte sequences as
6320 a whole, but byte-by-byte, and the latter is what \*(UA actually reads.
6321 This variable specifies the timeout in milliseconds that the MLE (see
6322 .Sx "On terminal control and line editor" )
6323 waits for more bytes to arrive unless it considers a sequence
6329 \*(BO Causes automatic display of a header summary after executing a
6331 command, and thus complements the standard variable
6333 which controls header summary display on program startup.
6334 It is only meaningful if
6340 \*(BO Sets some cosmetical features to traditional BSD style;
6341 has the same affect as setting
6343 and all other variables prefixed with
6345 it also changes the behaviour of
6347 (which does not exist in BSD).
6351 \*(BO Changes the letters shown in the first column of a header
6352 summary to traditional BSD style.
6356 \*(BO Changes the display of columns in a header summary to traditional
6361 \*(BO Changes some informational messages to traditional BSD style.
6367 field to appear immediately after the
6369 field in message headers and with the
6371 .Sx "COMMAND ESCAPES" .
6375 The value that should appear in the
6379 MIME header fields when no character set conversion of the message data
6381 This defaults to US-ASCII, and the chosen character set should be
6382 US-ASCII compatible.
6386 \*(OP The default 8-bit character set that is used as an implicit last
6387 member of the variable
6389 This defaults to UTF-8 if character-set conversion capabilities are
6390 available, and to ISO-8859-1 otherwise, in which case the only supported
6393 and this variable is effectively ignored.
6394 Refer to the section
6395 .Sx "Character sets"
6396 for the complete picture of character set conversion in \*(UA.
6399 .It Va charset-unknown-8bit
6400 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
6402 the content of a mail message by using a character set with the name
6404 Because of the unclassified nature of this character set \*(UA will not
6405 be capable to convert this character set to any other character set.
6406 If this variable is set any message part which uses the character set
6408 is assumed to really be in the character set given in the value,
6409 otherwise the (final) value of
6411 is used for this purpose.
6413 This variable will also be taken into account if a MIME type (see
6414 .Sx "The mime.types files" )
6415 of a MIME message part that uses the
6417 character set is forcefully treated as text.
6421 The default value for the
6426 .It Va colour-disable
6427 \*(BO\*(OP Forcefully disable usage of colours.
6428 Also see the section
6429 .Sx "Coloured display" .
6433 \*(BO\*(OP Whether colour shall be used for output that is paged through
6435 Note that pagers may need special flags, e.g.,
6443 in order to support colours.
6444 Often doing manual adjustments is unnecessary since \*(UA may perform
6445 adjustments dependent on the value of the environment variable
6447 (see there for more).
6451 In a(n interactive) terminal session, then if this valued variable is
6452 set it will be used as a threshold to determine how many lines the given
6453 output has to span before it will be displayed via the configured
6457 can be forced by setting this to the value
6459 setting it without a value will deduce the current height of the
6460 terminal screen to compute the treshold (see
6468 Define a set of custom headers to be injected into newly composed or
6469 forwarded messages; it is also possible to create custom headers in
6472 which can be automated by setting one of the hooks
6473 .Va on-compose-done-shell
6475 .Va on-compose-done .
6476 The value is interpreted as a comma-separated list of custom headers to
6477 be injected, to include commas in the header bodies escape them with
6479 \*(ID Overwriting of automatically managed headers is neither supported
6482 .Dl set customhdr='Hdr1: Body1-1\e, Body1-2, Hdr2: Body2'
6488 the message date, if any is to be displayed according to the format of
6490 is by default taken from the
6492 line of the message.
6493 If this variable is set the date as given in the
6495 header field is used instead, converted to local time.
6496 To control the display format of the date assign a valid
6501 format should not be used, because \*(UA does not take embedded newlines
6502 into account when calculating how many lines fit onto the screen.)
6504 .Va datefield-markout-older .
6507 .It Va datefield-markout-older
6508 This variable, when set in addition to
6512 messages (concept is rather comparable to the
6514 option of the POSIX utility
6516 The content interpretation is identical to
6521 \*(BO Enables debug messages and obsoletion warnings, disables the
6522 actual delivery of messages and also implies
6528 .It Va disposition-notification-send
6530 .Ql Disposition-Notification-To:
6531 header (RFC 3798) with the message.
6535 .\" TODO .It Va disposition-notification-send-HOST
6537 .\".Va disposition-notification-send
6538 .\" for SMTP accounts on a specific host.
6539 .\" TODO .It Va disposition-notification-send-USER@HOST
6541 .\".Va disposition-notification-send
6542 .\"for a specific account.
6546 \*(BO When dot is set, a period
6548 on a line by itself during message input in (interactive) compose mode
6549 will be treated as end-of-message (in addition to the normal end-of-file
6558 .It Va dotlock-ignore-error
6559 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as
6561 .Sx "primary system mailbox" Ns
6562 es (see, e.g., the notes on
6564 .Sx "filename transformations"
6567 sections as well as the documentation of
6569 will be protected with so-called dotlock files\(emthe traditional mail
6570 spool file locking method\(emin addition to system file locking.
6571 Because \*(UA ships with a privilege-separated dotlock creation program
6572 that should always be able to create such a dotlock file there is no
6573 good reason to ignore dotlock file creation errors, and thus these are
6574 fatal unless this variable is set.
6578 \*(BO If this variable is set then the editor is started automatically
6579 when a message is composed in interactive mode, as if the
6581 .Sx "COMMAND ESCAPES"
6585 variable is implied for this automatically spawned editor session.
6589 \*(BO When a message is edited while being composed,
6590 its header is included in the editable text.
6600 fields are accepted within the header, other fields are ignored.
6604 \*(BO When entering interactive mode \*(UA normally writes
6605 .Dq \&No mail for user
6606 and exits immediately if a mailbox is empty or does not exist.
6607 If this variable is set \*(UA starts even with an empty or nonexistent
6608 mailbox (the latter behaviour furtherly depends upon
6615 .Ql Content-Transfer-Encoding
6616 to use in outgoing text messages and message parts, where applicable.
6617 (7-bit clean text messages are sent as-is, without a transfer encoding.)
6620 .Bl -tag -compact -width "_%%_"
6623 8-bit transport effectively causes the raw data be passed through
6624 unchanged, but may cause problems when transferring mail messages over
6625 channels that are not ESMTP (RFC 1869) compliant.
6626 Also, several input data constructs are not allowed by the
6627 specifications and may cause a different transfer-encoding to be used.
6628 .It Ql quoted-printable
6630 Quoted-printable encoding is 7-bit clean and has the property that ASCII
6631 characters are passed through unchanged, so that an english message can
6632 be read as-is; it is also acceptible for other single-byte locales that
6633 share many characters with ASCII, like, e.g., ISO-8859-1.
6634 The encoding will cause a large overhead for messages in other character
6635 sets: e.g., it will require up to twelve (12) bytes to encode a single
6636 UTF-8 character of four (4) bytes.
6638 .Pf (Or\0 Ql b64 . )
6639 The default encoding, it is 7-bit clean and will always be used for
6641 This encoding has a constant input:output ratio of 3:4, regardless of
6642 the character set of the input data it will encode three bytes of input
6643 to four bytes of output.
6644 This transfer-encoding is not human readable without performing
6650 If defined, the first character of the value of this variable
6651 gives the character to use in place of tilde
6654 .Sx "COMMAND ESCAPES" .
6655 If set to the empty string, command escapes are disabled.
6659 If not set then file and command pipeline targets are not allowed,
6660 and any such address will be filtered out, giving a warning message.
6661 If set without a value then all possible recipient address
6662 specifications will be accepted \(en see the section
6663 .Sx "On sending mail, and non-interactive mode"
6665 To accept them, but only in interactive mode, or when tilde commands
6666 were enabled explicitly by using one of the command line options
6670 set this to the (case-insensitive) value
6672 (it actually acts like
6673 .Ql restrict,-all,+name,+addr ,
6674 so that care for ordering issues must be taken) .
6676 In fact the value is interpreted as a comma-separated list of values.
6679 then the existence of disallowed specifications is treated as a hard
6680 send error instead of only filtering them out.
6681 The remaining values specify whether a specific type of recipient
6682 address specification is allowed (optionally indicated by a plus sign
6684 prefix) or disallowed (prefixed with a hyphen
6688 addresses all possible address specifications,
6692 command pipeline targets,
6694 plain user names and (MTA) aliases (\*(OB
6696 may be used as an alternative syntax to
6701 These kind of values are interpreted in the given order, so that
6702 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
6703 will cause hard errors for any non-network address recipient address
6704 unless \*(UA is in interactive mode or has been started with the
6708 command line option; in the latter case(s) any address may be used, then.
6710 Historically invalid network addressees are silently stripped off.
6711 To change this and ensure that any encountered invalid email address
6712 instead causes a hard error, ensure the string
6714 is an entry in the above list.
6715 Setting this automatically enables network addressees
6716 (it actually acts like
6717 .Ql failinvaddr,+addr ,
6718 so that care for ordering issues must be taken) .
6722 Unless this variable is set additional
6724 (Mail-Transfer-Agent)
6725 arguments from the command line, as can be given after a
6727 separator, are ignored due to safety reasons.
6728 However, if set to the special (case-insensitive) value
6730 then the presence of additional MTA arguments is treated as a hard
6731 error that causes \*(UA to exit with failure status.
6732 A lesser strict variant is the otherwise identical
6734 which does accept such arguments in interactive mode, or if tilde
6735 commands were enabled explicitly by using one of the command line options
6742 \*(RO String giving a list of features \*(UA, preceded with a plus-sign
6744 if the feature is available, and a minus-sign
6747 The output of the command
6749 will include this information.
6753 \*(BO This setting reverses the meanings of a set of reply commands,
6754 turning the lowercase variants, which by default address all recipients
6755 included in the header of a message
6756 .Pf ( Ic reply , respond , followup )
6757 into the uppercase variants, which by default address the sender only
6758 .Pf ( Ic Reply , Respond , Followup )
6761 .Ic replysender , respondsender , followupsender
6763 .Ic replyall , respondall , followupall
6764 are not affected by the current setting of
6769 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
6770 It is possible to install file hooks which will be used by the
6772 command in order to be able to transparently handle (through an
6773 intermediate temporary file) files with specific
6775 s: the variable values can include shell snippets and are expected to
6776 write data to standard output / read data from standard input,
6778 \*(ID The variables may not be changed while there is a mailbox
6780 .Bd -literal -offset indent
6781 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
6782 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
6783 record=+null-sent.xy
6788 The default path under which mailboxes are to be saved:
6789 file names that begin with the plus-sign
6791 will have the plus-sign replaced with the value of this variable if set,
6792 otherwise the plus-sign will remain unchanged when doing
6794 .Sx "filename transformations" ;
6795 see the introduction of
6797 as well as the documentation of
6799 for more on this topic.
6800 The value supports a subset of transformations itself, and if the
6801 non-empty value does not start with a solidus
6805 will be prefixed automatically.
6809 This variable can be set to the name of a
6811 macro which will be called whenever a
6814 The macro will also be invoked when new mail arrives,
6815 but message lists for commands executed from the macro
6816 only include newly arrived messages then.
6818 are activated by default in a folder hook, causing the covered settings
6819 to be reverted once the folder is left again.
6822 Macro behaviour, including option localization, will change in v15.
6823 One should be aware of that and possibly embed version checks in the
6824 used resource file(s).
6827 .It Va folder-hook-FOLDER
6832 Unlike other folder specifications, the fully expanded name of a folder,
6833 without metacharacters, is used to avoid ambiguities.
6834 However, if the mailbox resides under
6838 specification is tried in addition, e.g., if
6842 (and thus relative to the user's home directory) then
6843 .Pa /home/usr1/mail/sent
6845 .Ql folder-hook-/home/usr1/mail/sent
6846 first, but then followed by
6847 .Ql folder-hook-+sent .
6851 \*(BO Controls whether a
6852 .Ql Mail-Followup-To:
6853 header is generated when sending messages to known mailing lists.
6855 .Va followup-to-honour
6857 .Ic mlist , mlsubscribe , reply
6862 .It Va followup-to-honour
6864 .Ql Mail-Followup-To:
6865 header is honoured when group-replying to a message via
6869 This is a quadoption; if set without a value it defaults to
6879 .It Va forward-as-attachment
6880 \*(BO Original messages are normally sent as inline text with the
6883 and only the first part of a multipart message is included.
6884 With this setting enabled messages are sent as unmodified MIME
6886 attachments with all of their parts included.
6890 The address (or a list of addresses) to put into the
6892 field of the message header, quoting RFC 5322:
6893 the author(s) of the message, that is, the mailbox(es) of the person(s)
6894 or system(s) responsible for the writing of the message.
6897 ing to messages these addresses are handled as if they were in the
6901 If the machine's hostname is not valid at the Internet (for example at
6902 a dialup machine) then either this variable or
6904 (\*(IN and with a defined SMTP protocol in
6907 adds even more fine-tuning capabilities),
6911 contains more than one address,
6914 variable is required (according to the standard RFC 5322).
6916 If a file-based MTA is used, then
6918 (or, if that contains multiple addresses,
6920 can nonetheless be enforced to appear as the envelope sender address at
6921 the MTA protocol level (the RFC 5321 reverse-path), either by using the
6923 command line option (with an empty argument; see there for the complete
6924 picture on this topic), or by setting the internal variable
6925 .Va r-option-implicit .
6929 \*(BO When replying to or forwarding a message \*(UA normally removes
6930 the comment and name parts of email addresses.
6931 If this variable is set such stripping is not performed,
6932 and comments, names etc. are retained.
6936 The string to put before the text of a message with the
6940 .Va forward-as-attachment
6943 .Dq -------- Original Message --------
6944 if unset; No heading is put if it is set to the empty string.
6948 \*(BO Causes the header summary to be written at startup and after
6949 commands that affect the number of messages or the order of messages in
6950 the current folder; enabled by default.
6951 The command line option
6957 complements this and controls header summary display on folder changes.
6962 A format string to use for the summary of
6964 similar to the ones used for
6967 Format specifiers in the given string start with a percent character
6969 and may be followed by an optional decimal number indicating the field
6970 width \(em if that is negative, the field is to be left-aligned.
6971 Valid format specifiers are:
6974 .Bl -tag -compact -width "_%%_"
6976 A plain percent character.
6979 a space character but for the current message
6981 for which it expands to
6985 a space character but for the current message
6987 for which it expands to
6990 \*(OP The spam score of the message, as has been classified via the
6993 Shows only a replacement character if there is no spam support.
6995 Message attribute character (status flag); the actual content can be
6999 The date when the message was received, or the date found in the
7003 variable is set (optionally to a date display format string).
7005 The indenting level in threaded mode.
7007 The address of the message sender.
7009 The message thread tree structure.
7010 (Note that this format does not support a field width.)
7012 The number of lines of the message, if available.
7016 The number of octets (bytes) in the message, if available.
7018 Message subject (if any).
7020 Message subject (if any) in double quotes.
7022 Message recipient flags: is the addressee of the message a known or
7023 subscribed mailing list \(en see
7028 The position in threaded/sorted order.
7032 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
7034 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
7045 .It Va headline-bidi
7046 Bidirectional text requires special treatment when displaying headers,
7047 because numbers (in dates or for file sizes etc.) will not affect the
7048 current text direction, in effect resulting in ugly line layouts when
7049 arabic or other right-to-left text is to be displayed.
7050 On the other hand only a minority of terminals is capable to correctly
7051 handle direction changes, so that user interaction is necessary for
7053 Note that extended host system support is required nonetheless, e.g.,
7054 detection of the terminal character set is one precondition;
7055 and this feature only works in an Unicode (i.e., UTF-8) locale.
7057 In general setting this variable will cause \*(UA to encapsulate text
7058 fields that may occur when displaying
7060 (and some other fields, like dynamic expansions in
7062 with special Unicode control sequences;
7063 it is possible to fine-tune the terminal support level by assigning
7065 no value (or any value other than
7070 will make \*(UA assume that the terminal is capable to properly deal
7071 with Unicode version 6.3, in which case text is embedded in a pair of
7072 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
7074 In addition no space on the line is reserved for these characters.
7076 Weaker support is chosen by using the value
7078 (Unicode 6.3, but reserve the room of two spaces for writing the control
7079 sequences onto the line).
7084 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
7085 again reserves room for two spaces in addition.
7089 \*(OP If a line editor is available then this can be set to
7090 name the (expandable) path of the location of a permanent history file.
7093 .It Va history-gabby
7094 \*(BO\*(OP Add more entries to the history as is normally done.
7097 .It Va history-gabby-persist
7098 \*(BO\*(OP \*(UA's own MLE will not save the additional
7100 entries in persistent storage unless this variable is set.
7101 On the other hand it will not loose the knowledge of whether
7102 a persistent entry was gabby or not.
7108 \*(OP If a line editor is available this value restricts the
7109 amount of history entries that are saved into a set and valid
7111 A value of less than 0 disables this feature;
7112 note that loading and incorporation of
7114 upon program startup can also be suppressed by doing this.
7115 If unset or 0, a default value will be used.
7116 Dependent on the available line editor this will also define the
7117 number of history entries in memory;
7118 it is also editor-specific whether runtime updates of this value will
7123 \*(BO This setting controls whether messages are held in the system
7125 and it is set by default.
7129 Use this string as hostname when expanding local addresses instead of
7130 the value obtained from
7139 Note that when SMTP transport is not used (via
7141 then it is normally the responsibility of the MTA to create these
7142 fields, \*(IN in conjunction with SMTP however
7144 also influences the results:
7145 one should produce some test messages with the desired combination of
7154 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
7155 names according to the rules of IDNA (internationalized domain names
7157 Since the IDNA code assumes that domain names are specified with the
7159 character set, an UTF-8 locale charset is required to represent all
7160 possible international domain names (before conversion, that is).
7164 \*(BO Ignore interrupt signals from the terminal while entering
7165 messages; instead echo them as
7167 characters and discard the current line.
7171 \*(BO Ignore end-of-file conditions
7172 .Pf ( Ql control-D )
7173 in compose mode on message input and in interactive command input.
7174 If set an interactive command input session can only be left by
7175 explicitly using one of the commands
7179 and message input in compose mode can only be terminated by entering
7182 on a line by itself or by using the
7184 .Sx "COMMAND ESCAPES" ;
7186 overrides a setting of
7191 If this is set to a non-empty string it will specify the users
7193 .Sx "primary system mailbox" ,
7196 and the system-dependent default, and (thus) be used to replace
7200 .Sx "filename transformations" ;
7201 see the introduction of
7203 as well as the command
7205 for more on this topic.
7206 The value supports a subset of transformations itself.
7214 .Sx "COMMAND ESCAPES"
7217 option for indenting messages,
7218 in place of the normal tabulator character
7220 which is the default.
7221 Be sure to quote the value if it contains spaces or tabs.
7225 \*(BO If set, an empty system (MBOX) mailbox file is not removed.
7226 Note that, in conjunction with
7229 .Ev POSIXLY_CORRECT )
7230 any empty file will be removed unless this variable is set.
7231 This may improve the interoperability with other mail user agents
7232 when using a common folder directory, and prevents malicious users
7233 from creating fake mailboxes in a world-writable spool directory.
7234 \*(ID Only local regular (MBOX) files are covered, Maildir or other
7235 mailbox types will never be removed, even if empty.
7238 .It Va keep-content-length
7239 \*(BO When (editing messages and) writing
7241 mailbox files \*(UA can be told to keep the
7245 header fields that some MUAs generate by setting this variable.
7246 Since \*(UA does neither use nor update these non-standardized header
7247 fields (which in itself shows one of their conceptual problems),
7248 stripping them should increase interoperability in between MUAs that
7249 work with with same mailbox files.
7250 Note that, if this is not set but
7251 .Va writebackedited ,
7252 as below, is, a possibly performed automatic stripping of these header
7253 fields already marks the message as being modified.
7257 \*(BO When a message is saved it is usually discarded from the
7258 originating folder when \*(UA is quit.
7259 This setting causes all saved message to be retained.
7262 .It Va line-editor-disable
7263 \*(BO Turn off any enhanced line editing capabilities (see
7264 .Sx "On terminal control and line editor"
7268 .It Va line-editor-no-defaults
7269 \*(BO\*(OP Do not establish any default key binding.
7273 \*(BO When a message is replied to and this variable is set,
7274 it is marked as having been answered.
7275 This mark has no technical meaning in the mail system;
7276 it just causes messages to be marked in the header summary,
7277 and makes them specially addressable.
7281 \*(BO Internal development variable.
7284 .It Va message-id-disable
7285 \*(BO By setting this variable the generation of
7287 can be completely suppressed, effectively leaving this task up to the
7289 (Mail-Transfer-Agent) or the SMTP server.
7290 (According to RFC 5321 a SMTP server is not required to add this
7291 field by itself, so it should be ensured that it accepts messages without
7295 .It Va message-inject-head
7296 A string to put at the beginning of each new message.
7297 The escape sequences tabulator
7304 .It Va message-inject-tail
7305 A string to put at the end of each new message.
7306 The escape sequences tabulator
7314 \*(BO Usually, when an
7316 expansion contains the sender, the sender is removed from the expansion.
7317 Setting this option suppresses these removals.
7322 option to be passed through to the
7324 (Mail-Transfer-Agent); though most of the modern MTAs no longer document
7325 this flag, no MTA is known which does not support it (for historical
7329 .It Va mime-allow-text-controls
7330 \*(BO When sending messages, each part of the message is MIME-inspected
7331 in order to classify the
7334 .Ql Content-Transfer-Encoding:
7337 that is required to send this part over mail transport, i.e.,
7338 a computation rather similar to what the
7340 command produces when used with the
7344 This classification however treats text files which are encoded in
7345 UTF-16 (seen for HTML files) and similar character sets as binary
7346 octet-streams, forcefully changing any
7351 .Ql application/octet-stream :
7352 If that actually happens a yet unset charset MIME parameter is set to
7354 effectively making it impossible for the receiving MUA to automatically
7355 interpret the contents of the part.
7357 If this variable is set, and the data was unambiguously identified as
7358 text data at first glance (by a
7362 file extension), then the original
7364 will not be overwritten.
7367 .It Va mime-alternative-favour-rich
7368 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
7369 HTML) will be preferred in favour of included plain text versions when
7370 displaying messages, provided that a handler exists which produces
7371 output that can be (re)integrated into \*(UA's normal visual display.
7372 (E.g., at the time of this writing some newsletters ship their full
7373 content only in the rich HTML part, whereas the plain text part only
7374 contains topic subjects.)
7377 .It Va mime-counter-evidence
7380 field is used to decide how to handle MIME parts.
7381 Some MUAs however do not use
7383 or a similar mechanism to correctly classify content, but simply specify
7384 .Ql application/octet-stream ,
7385 even for plain text attachments like
7387 If this variable is set then \*(UA will try to classify such MIME
7388 message parts on its own, if possible, for example via a possibly
7389 existing attachment filename.
7390 A non-empty value may also be given, in which case a number is expected,
7391 actually a carrier of bits.
7392 Creating the bit-carrying number is a simple addition:
7393 .Bd -literal -offset indent
7394 ? !echo Value should be set to $((2 + 4 + 8))
7395 Value should be set to 14
7398 .Bl -bullet -compact
7400 If bit two is set (2) then the detected
7402 content-type will be carried along with the message and be used for
7404 .Va pipe-TYPE/SUBTYPE
7405 is responsible for the MIME part, shall that question arise;
7406 when displaying such a MIME part the part-info will indicate the
7407 overridden content-type by showing a plus-sign
7410 If bit three is set (4) then the counter-evidence is always produced
7411 and a positive result will be used as the MIME type, even forcefully
7412 overriding the parts given MIME type.
7414 If bit four is set (8) then as a last resort the actual content of
7415 .Ql application/octet-stream
7416 parts will be inspected, so that data which looks like plain text can be
7421 .It Va mimetypes-load-control
7422 Can be used to control which of the
7424 databases are loaded by \*(UA, as furtherly described in the section
7425 .Sx "The mime.types files" .
7428 is part of the option value, then the user's personal
7430 file will be loaded (if it exists); likewise the letter
7432 controls loading of the system wide
7433 .Pa /etc/mime.types ;
7434 directives found in the user file take precedence, letter matching is
7436 If this variable is not set \*(UA will try to load both files.
7437 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
7438 but they will be matched last (the order can be listed via
7441 More sources can be specified by using a different syntax: if the
7442 value string contains an equals sign
7444 then it is instead parsed as a comma-separated list of the described
7447 pairs; the given filenames will be expanded and loaded, and their
7448 content may use the extended syntax that is described in the section
7449 .Sx "The mime.types files" .
7450 Directives found in such files always take precedence (are prepended to
7451 the MIME type cache).
7456 To choose an alternate Mail-Transfer-Agent, set this option to either
7457 the full pathname of an executable (optionally prefixed with a
7459 protocol indicator), or \*(OPally a SMTP protocol URL, e.g., \*(IN
7461 .Dl smtps?://[user[:password]@]server[:port]
7464 .Ql [smtp://]server[:port] . )
7465 The default has been chosen at compie time.
7466 All supported data transfers are executed in child processes, which
7467 run asynchronously, and without supervision, unless either the
7472 If such a child receives a TERM signal, it will abort and
7479 For a file-based MTA it may be necessary to set
7481 in in order to choose the right target of a modern
7484 It will be passed command line arguments from several possible sources:
7487 if set, from the command line if given and the variable
7490 Argument processing of the MTA will be terminated with a
7495 The otherwise occurring implicit usage of the following MTA command
7496 line arguments can be disabled by setting the boolean variable
7497 .Va mta-no-default-arguments
7498 (which will also disable passing
7502 (for not treating a line with only a dot
7504 character as the end of input),
7512 variable is set); in conjunction with the
7514 command line option \*(UA will also (not) pass
7520 \*(OP \*(UA can send mail over SMTP network connections to a single
7521 defined SMTP smarthost, the access URL of which has to be assigned to
7523 To use this mode it is helpful to read
7524 .Sx "On URL syntax and credential lookup" .
7525 It may be necessary to set the
7527 variable in order to use a specific combination of
7532 with some mail providers.
7535 .Bl -bullet -compact
7537 The plain SMTP protocol (RFC 5321) that normally lives on the
7538 server port 25 and requires setting the
7539 .Va smtp-use-starttls
7540 variable to enter a SSL/TLS encrypted session state.
7541 Assign a value like \*(IN
7542 .Ql smtp://[user[:password]@]server[:port]
7544 .Ql smtp://server[:port] )
7545 to choose this protocol.
7547 The so-called SMTPS which is supposed to live on server port 465
7548 and is automatically SSL/TLS secured.
7549 Unfortunately it never became a standardized protocol and may thus not
7550 be supported by your hosts network service database
7551 \(en in fact the port number has already been reassigned to other
7554 SMTPS is nonetheless a commonly offered protocol and thus can be
7555 chosen by assigning a value like \*(IN
7556 .Ql smtps://[user[:password]@]server[:port]
7558 .Ql smtps://server[:port] ) ;
7559 due to the mentioned problems it is usually necessary to explicitly
7564 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7565 lives on server port 587 and is practically identically to the SMTP
7566 protocol from \*(UA's point of view beside that; it requires setting the
7567 .Va smtp-use-starttls
7568 variable to enter a SSL/TLS secured session state.
7569 Assign a value like \*(IN
7570 .Ql submission://[user[:password]@]server[:port]
7572 .Ql submission://server[:port] ) .
7577 .It Va mta-arguments
7578 Arguments to pass through to a file-based
7580 can be given via this variable, the content of which will be split up in
7581 a vector of arguments, to be joined onto other possible MTA options:
7583 .Dl set mta-arguments='-t -X \&"/tmp/my log\&"'
7586 .It Va mta-no-default-arguments
7587 \*(BO Unless this variable is set \*(UA will pass some well known
7588 standard command line options to a file-based
7590 (Mail-Transfer-Agent), see there for more.
7594 Many systems use a so-called
7596 environment to ensure compatibility with
7598 This works by inspecting the name that was used to invoke the mail
7600 If this variable is set then the mailwrapper (the program that is
7601 actually executed when calling the file-based
7603 will treat its contents as that name.
7608 .It Va NAIL_EXTRA_RC
7609 The name of an optional startup file to be read last.
7610 This variable has an effect only if it is set in any of the
7611 .Sx "Resource files" ,
7612 it is not imported from the environment.
7613 Use this file for commands that are not understood by other POSIX
7618 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
7619 \*(BO\*(IN\*(OP Used to control usage of the users
7621 file for lookup of account credentials, as documented in the section
7622 .Sx "On URL syntax and credential lookup"
7626 .Sx "The .netrc file"
7627 documents the file format.
7639 then \*(UA will read the output of a shell pipe instead of the users
7641 file if this variable is set (to the desired shell command).
7642 This can be used to, e.g., store
7646 .Dl set netrc-pipe='gpg -qd ~/.netrc.pgp'
7650 If this variable has the value
7652 newly created local folders will be in Maildir format.
7656 Checks for new mail in the current folder each time the prompt is shown.
7657 A Maildir folder must be re-scanned to determine if new mail has arrived.
7658 If this variable is set to the special value
7660 then a Maildir folder will not be rescanned completely, but only
7661 timestamp changes are detected.
7665 .It Va on-compose-done-shell , on-compose-done
7666 These hooks run once the normal compose mode is finished, but before the
7667 .Va on-compose-leave
7668 macro hook is called, the
7671 Both hooks will be executed in a subprocess, with their input and output
7672 connected to \*(UA such that they can act as if they would be an
7674 The difference in between them is that the former is a
7676 command, whereas the latter is a normal \*(UA macro, but which is
7677 restricted to a small set of commands (the
7681 will indicate the said capability), just enough for the purpose of
7682 controlling the real \*(UA instance sufficiently.
7684 are by default enabled (in the parent) for (the lifetime of) these
7685 hooks, causing covered setting to be forgotten after the message has
7688 During execution of these hook \*(UA will temporarily forget whether it
7689 has been started in interactive mode, (a restricted set of)
7690 .Sx "COMMAND ESCAPES"
7691 will always be available, and for guaranteed reproduceabilities sake
7693 will be set to its default.
7694 The compose mode command
7696 has been especially designed for scriptability (via these hooks).
7697 The first line the hook will read on its standard input is the protocol
7698 version of said command escape, currently
7700 backward incompatible protocol changes are to be expected in the
7701 future, and it is advisable to make use of the protocol version.
7702 \*(ID because most \*(UA commands do not take this new functionality
7703 into account but are ment for human interaction special care must be
7704 taken to avoid deadlocks because of unexpected control flow; i.e., that
7705 both involved processes wait for more input to happen at the same time,
7706 or one doesn't expect more input but the other is stuck waiting for
7707 consumation of its output.
7708 .Bd -literal -offset indent
7709 wysh set on-compose-done-shell=$'\e
7711 printf "hello $version! Headers: ";\e
7712 echo \e'~^header list\e';\e
7713 read status result;\e
7714 echo "status=$status result=$result";\e
7717 set on-compose-done=ocdm
7720 echo version is $ver, escape=$escape
7721 if $features !@ +regex
7722 echoerr 'Need regular-expression support, aborting send'
7725 echo '~^header list'
7728 echoerr 'Failed to read header list, bailing out'
7732 echo '~^header insert cc Diet is your <mirr.or>'
7735 echoerr 'Failed to insert Cc: header, bailing out'
7744 .It Va on-compose-enter , on-compose-leave
7745 Macro hooks which will be executed before compose mode is entered, and
7746 after composing has been finished (but before the
7748 is injected, etc.), respectively.
7750 are by default enabled for these hooks, causing any setting to be
7751 forgotten after the message has been sent.
7752 The following variables will be set temporarily during execution of the
7755 .Bl -tag -compact -width ".It Va compose_subject"
7758 .It Va compose-sender
7760 .It Va compose-to , compose-cc , compose-bcc
7761 The list of receiver addresses as a space-separated list.
7762 .It Va compose-subject
7768 \*(BO Causes the filename given in the
7771 and the sender-based filenames for the
7775 commands to be interpreted relative to the directory given in the
7777 variable rather than to the current directory,
7778 unless it is set to an absolute pathname.
7782 \*(BO If set, each message feed through the command given for
7784 is followed by a formfeed character
7788 .It Va password-USER@HOST , password-HOST , password
7789 \*(IN Variable chain that sets a password, which is used in case none has
7790 been given in the protocol and account-specific URL;
7791 as a last resort \*(UA will ask for a password on the user's terminal if
7792 the authentication method requires a password.
7793 Specifying passwords in a startup file is generally a security risk;
7794 the file should be readable by the invoking user only.
7796 .It Va password-USER@HOST
7797 \*(OU (see the chain above for \*(IN)
7798 Set the password for
7802 If no such variable is defined for a host,
7803 the user will be asked for a password on standard input.
7804 Specifying passwords in a startup file is generally a security risk;
7805 the file should be readable by the invoking user only.
7809 \*(BO Send messages to the
7811 command without performing MIME and character set conversions.
7815 .It Va pipe-TYPE/SUBTYPE
7816 When a MIME message part of type
7818 (case-insensitive) is displayed or quoted,
7819 its text is filtered through the value of this variable interpreted as
7823 forces interpretation of the message part as plain text, e.g.,
7824 .Ql set pipe-application/xml=@
7825 will henceforth display XML
7827 (The same could also be achieved by adding a MIME type marker with the
7830 And \*(OPally MIME type handlers may be defined via
7831 .Sx "The Mailcap files"
7832 \(em corresponding flag strings are shown in parenthesis below.)
7837 can in fact be used to adjust usage and behaviour of a following shell
7838 command specification by appending trigger characters to it, e.g., the
7839 following hypothetical command specification could be used:
7840 .Bd -literal -offset indent
7841 set pipe-X/Y='@*!++=@vim ${NAIL_FILENAME_TEMPORARY}'
7845 .Bl -tag -compact -width ".It Ql __"
7847 Simply by using the special
7849 prefix the MIME type (shell command) handler will only be invoked to
7850 display or convert the MIME part if the message is addressed directly
7851 and alone by itself.
7852 Use this trigger to disable this and always invoke the handler
7853 .Pf ( Cd x-mailx-always ) .
7856 If set the handler will not be invoked when a message is to be quoted,
7857 but only when it will be displayed
7858 .Pf ( Cd x-mailx-noquote ) .
7861 The command will be run asynchronously, i.e., without blocking \*(UA,
7862 which may be a handy way to display a, e.g., PDF file while also
7863 continuing to read the mail message
7864 .Pf ( Cd x-mailx-async ) .
7865 Asynchronous execution implies
7869 The command must be run on an interactive terminal, \*(UA will
7870 temporarily release the terminal to it
7871 .Pf ( Cd needsterminal ) .
7872 This flag is mutual exclusive with
7874 will only be used in interactive mode and implies
7878 Request creation of a zero-sized temporary file, the absolute pathname
7879 of which will be made accessible via the environment variable
7880 .Ev NAIL_FILENAME_TEMPORARY
7881 .Pf ( Cd x-mailx-tmpfile ) .
7882 If this trigger is given twice then the file will be unlinked
7883 automatically by \*(UA when the command loop is entered again at latest
7884 .Pf ( Cd x-mailx-tmpfile-unlink ) .
7885 (Do not use this for asynchronous handlers.)
7888 Normally the MIME part content is passed to the handler via standard
7889 input; if this flag is set then the data will instead be written into
7890 .Ev NAIL_FILENAME_TEMPORARY
7891 .Pf ( Cd x-mailx-tmpfile-fill ) ,
7892 the creation of which is implied; note however that in order to cause
7893 deletion of the temporary file you still have to use two plus signs
7898 To avoid ambiguities with normal shell command content you can use
7899 another at-sign to forcefully terminate interpretation of remaining
7901 (Any character not in this list will have the same effect.)
7905 Some information about the MIME part to be displayed is embedded into
7906 the environment of the shell command:
7909 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
7912 The MIME content-type of the part, if known, the empty string otherwise.
7915 .It Ev NAIL_CONTENT_EVIDENCE
7917 .Va mime-counter-evidence
7918 includes the carry-around-bit (2), then this will be set to the detected
7919 MIME content-type; not only then identical to
7920 .Ev \&\&NAIL_CONTENT
7924 .It Ev NAIL_FILENAME
7925 The filename, if any is set, the empty string otherwise.
7928 .It Ev NAIL_FILENAME_GENERATED
7932 .It Ev NAIL_FILENAME_TEMPORARY
7933 If temporary file creation has been requested through the command prefix
7934 this variable will be set and contain the absolute pathname of the
7939 The temporary directory that \*(UA uses.
7940 Usually identical to
7942 but guaranteed to be set and usable by child processes;
7943 to ensure the latter condition for
7945 also, it will be set.
7950 .It Va pipe-EXTENSION
7951 This is identical to
7952 .Va pipe-TYPE/SUBTYPE
7955 (normalized to lowercase using character mappings of the ASCII charset)
7956 names a file extension, e.g.,
7958 Handlers registered using this method take precedence.
7961 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
7962 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
7963 The only possible value as of now is
7965 which is thus the default.
7968 .Mx Va pop3-bulk-load
7969 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
7970 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
7971 the messages, and only requests the message bodies on user request.
7972 For the POP3 protocol this means that the message headers will be
7974 If this variable is set then \*(UA will download only complete messages
7975 from the given POP3 server(s) instead.
7977 .Mx Va pop3-keepalive
7978 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
7979 \*(OP POP3 servers close the connection after a period of inactivity;
7980 the standard requires this to be at least 10 minutes,
7981 but practical experience may vary.
7982 Setting this variable to a numeric value greater than
7986 command to be sent each value seconds if no other operation is performed.
7989 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
7990 \*(BO\*(OP Unless this variable is set the
7992 authentication method will be used when connecting to a POP3 server that
7996 is that the password is not sent in clear text over the wire and that
7997 only a single packet is sent for the user/password tuple.
7999 .Va pop3-no-apop-HOST
8002 .Mx Va pop3-use-starttls
8003 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
8004 \*(BO\*(OP Causes \*(UA to issue a
8006 command to make an unencrypted POP3 session SSL/TLS encrypted.
8007 This functionality is not supported by all servers,
8008 and is not used if the session is already encrypted by the POP3S method.
8010 .Va pop3-use-starttls-HOST
8015 \*(BO This flag enables POSIX mode, which changes behaviour of \*(UA
8016 where that deviates from standardized behaviour.
8017 It will be set implicitly before the
8018 .Sx "Resource files"
8019 are loaded if the environment variable
8021 is set, and adjusting any of those two will be reflected by the other
8025 .It Va print-alternatives
8026 \*(BO When a MIME message part of type
8027 .Ql multipart/alternative
8028 is displayed and it contains a subpart of type
8030 other parts are normally discarded.
8031 Setting this variable causes all subparts to be displayed,
8032 just as if the surrounding part was of type
8033 .Ql multipart/mixed .
8037 The string used as a prompt in interactive mode.
8038 Whenever the variable is evaluated the value is shell-expanded using
8039 dollar-single-quote expansion mode (see
8041 and it is an error if the prompt expands to more than a single token.
8042 This (post-assignment, i.e., second) expansion can be used to embed
8043 status information, for example
8047 .Va -mailbox-display .
8048 In order to embed characters which should not be counted when
8049 calculating the visual width of the resulting string, enclose the
8050 characters of interest in a pair of reverse solidus escaped brackets:
8052 Prompting may be prevented by setting this to the null string
8054 .Ql set noprompt ) .
8058 This string is used for secondary prompts, but is otherwise identical to
8065 \*(BO Suppresses the printing of the version when first invoked.
8069 If set, \*(UA starts a replying message with the original message
8070 prefixed by the value of the variable
8072 Normally, a heading consisting of
8073 .Dq Fromheaderfield wrote:
8074 is put before the quotation.
8079 variable, this heading is omitted.
8082 is assigned, only the headers selected by the
8085 selection are put above the message body,
8088 acts like an automatic
8090 .Sx "COMMAND ESCAPES"
8094 is assigned, all headers are put above the message body and all MIME
8095 parts are included, making
8097 act like an automatic
8100 .Va quote-as-attachment .
8103 .It Va quote-as-attachment
8104 \*(BO Add the original message in its entirety as a
8106 MIME attachment when replying to a message.
8107 Note this works regardless of the setting of
8112 \*(OP Can be set in addition to
8114 Setting this turns on a more fancy quotation algorithm in that leading
8115 quotation characters are compressed and overlong lines are folded.
8117 can be set to either one or two (space separated) numeric values,
8118 which are interpreted as the maximum (goal) and the minimum line length,
8119 respectively, in a spirit rather equal to the
8121 program, but line-, not paragraph-based.
8122 If not set explicitly the minimum will reflect the goal algorithmically.
8123 The goal cannot be smaller than the length of
8125 plus some additional pad.
8126 Necessary adjustments take place silently.
8129 .It Va r-option-implicit
8130 \*(BO Setting this option evaluates the contents of
8132 (or, if that contains multiple addresses,
8134 and passes the results onto the used (file-based) MTA as described for the
8136 option (empty argument case).
8139 .It Va recipients-in-cc
8140 \*(BO On group replies, specify only the sender of the original mail in
8142 and mention the other recipients in the secondary
8144 By default all recipients of the original mail will be addressed via
8149 If defined, gives the pathname of the folder used to record all outgoing
8151 If not defined, then outgoing mail is not saved.
8152 When saving to this folder fails the message is not sent,
8153 but instead saved to
8157 .It Va record-resent
8158 \*(BO If both this variable and the
8165 commands save messages to the
8167 folder as it is normally only done for newly composed messages.
8170 .It Va reply-in-same-charset
8171 \*(BO If this variable is set \*(UA first tries to use the same
8172 character set of the original message for replies.
8173 If this fails, the mechanism described in
8174 .Sx "Character sets"
8175 is evaluated as usual.
8178 .It Va reply_strings
8179 Can be set to a comma-separated list of (case-insensitive according to
8180 ASCII rules) strings which shall be recognized in addition to the
8183 reply message indicators \(en builtin are
8185 which is mandated by RFC 5322, as well as the german
8190 A list of addresses to put into the
8192 field of the message header.
8193 Members of this list are handled as if they were in the
8198 .It Va reply-to-honour
8201 header is honoured when replying to a message via
8205 This is a quadoption; if set without a value it defaults to
8209 .It Va rfc822-body-from_
8210 \*(BO This variable can be used to force displaying a so-called
8212 line for messages that are embedded into an envelope mail via the
8214 MIME mechanism, for more visual convenience.
8218 \*(BO Enable saving of (partial) messages in
8220 upon interrupt or delivery error.
8224 The number of lines that represents a
8233 line display and scrolling via
8235 If this variable is not set \*(UA falls back to a calculation based upon
8236 the detected terminal window size and the baud rate: the faster the
8237 terminal, the more will be shown.
8238 Overall screen dimensions and pager usage is influenced by the
8239 environment variables
8247 .It Va searchheaders
8248 \*(BO Expand message-list specifiers in the form
8250 to all messages containing the substring
8254 The string search is case insensitive.
8258 \*(OP A comma-separated list of character set names that can be used in
8259 outgoing internet mail.
8260 The value of the variable
8262 is automatically appended to this list of character-sets.
8263 If no character set conversion capabilities are compiled into \*(UA then
8264 the only supported charset is
8267 .Va sendcharsets-else-ttycharset
8268 and refer to the section
8269 .Sx "Character sets"
8270 for the complete picture of character set conversion in \*(UA.
8273 .It Va sendcharsets-else-ttycharset
8274 \*(BO\*(OP If this variable is set, but
8276 is not, then \*(UA acts as if
8278 had been set to the value of the variable
8280 In effect this combination passes through the message data in the
8281 character set of the current locale (given that
8283 has not been set manually), i.e., without converting it to the
8285 fallback character set.
8286 Thus, mail message text will be in ISO-8859-1 encoding when send from
8287 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
8289 If no character set conversion capabilities are available in \*(UA then
8290 the only supported character set is
8295 An address that is put into the
8297 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
8298 responsible for the actual transmission of the message.
8299 This field should normally not be used unless the
8301 field contains more than one address, on which case it is required.
8304 address is handled as if it were in the
8308 .Va r-option-implicit .
8312 \*(OB Predecessor of
8316 .It Va sendmail-arguments
8317 \*(OB Predecessor of
8321 .It Va sendmail-no-default-arguments
8322 \*(OB\*(BO Predecessor of
8323 .Va mta-no-default-arguments .
8326 .It Va sendmail-progname
8327 \*(OB Predecessor of
8332 \*(BO When sending a message wait until the
8334 (including the builtin SMTP one) exits before accepting further commands.
8336 with this variable set errors reported by the MTA will be recognizable!
8337 If the MTA returns a non-zero exit status,
8338 the exit status of \*(UA will also be non-zero.
8342 \*(BO This setting causes \*(UA to start at the last message
8343 instead of the first one when opening a mail folder.
8347 \*(BO Causes \*(UA to use the sender's real name instead of the plain
8348 address in the header field summary and in message specifications.
8352 \*(BO Causes the recipient of the message to be shown in the header
8353 summary if the message was sent by the user.
8357 The string to expand
8360 .Sx "COMMAND ESCAPES" ) .
8364 The string to expand
8367 .Sx "COMMAND ESCAPES" ) .
8371 Must correspond to the name of a readable file if set.
8372 The file's content is then appended to each singlepart message
8373 and to the first part of each multipart message.
8374 Be warned that there is no possibility to edit the signature for an
8378 .It Va skipemptybody
8379 \*(BO If an outgoing message does not contain any text in its first or
8380 only message part, do not send it but discard it silently (see also the
8386 \*(OP Specifies a directory with CA certificates in PEM (Privacy
8387 Enhanced Mail) format for verification of S/MIME signed messages.
8390 .It Va smime-ca-file
8391 \*(OP Specifies a file with CA certificates in PEM format for
8392 verification of S/MIME signed messages.
8395 .It Va smime-cipher-USER@HOST , smime-cipher
8396 \*(OP Specifies the cipher to use when generating S/MIME encrypted
8397 messages (for the specified account).
8398 RFC 5751 mandates a default of
8401 Possible values are (case-insensitive and) in decreasing cipher strength:
8409 (DES EDE3 CBC, 168 bits; default if
8411 is not available) and
8415 The actually available cipher algorithms depend on the cryptographic
8416 library that \*(UA uses.
8417 \*(OP Support for more cipher algorithms may be available through
8418 dynamic loading via, e.g.,
8419 .Xr EVP_get_cipherbyname 3
8420 (OpenSSL) if \*(UA has been compiled to support this.
8423 .It Va smime-crl-dir
8424 \*(OP Specifies a directory that contains files with CRLs in PEM format
8425 to use when verifying S/MIME messages.
8428 .It Va smime-crl-file
8429 \*(OP Specifies a file that contains a CRL in PEM format to use when
8430 verifying S/MIME messages.
8433 .It Va smime-encrypt-USER@HOST
8434 \*(OP If this variable is set, messages send to the given receiver are
8435 encrypted before sending.
8436 The value of the variable must be set to the name of a file that
8437 contains a certificate in PEM format.
8439 If a message is sent to multiple recipients,
8440 each of them for whom a corresponding variable is set will receive an
8441 individually encrypted message;
8442 other recipients will continue to receive the message in plain text
8444 .Va smime-force-encryption
8446 It is recommended to sign encrypted messages, i.e., to also set the
8451 .It Va smime-force-encryption
8452 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
8455 .It Va smime-no-default-ca
8456 \*(BO\*(OP Do not load default CA locations when verifying S/MIME
8461 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
8462 and include the user's certificate as a MIME attachment.
8463 Signing a message enables a recipient to verify that the sender used
8464 a valid certificate,
8465 that the email addresses in the certificate match those in the message
8466 header and that the message content has not been altered.
8467 It does not change the message text,
8468 and people will be able to read the message as usual.
8470 .Va smime-sign-cert , smime-sign-include-certs
8472 .Va smime-sign-message-digest .
8474 .Mx Va smime-sign-cert
8475 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
8476 \*(OP Points to a file in PEM format.
8477 For the purpose of signing and decryption this file needs to contain the
8478 user's private key as well as his certificate.
8482 is always derived from the value of
8484 (or, if that contains multiple addresses,
8486 For the purpose of encryption the recipient's public encryption key
8487 (certificate) is expected; the command
8489 can be used to save certificates of signed messages (the section
8490 .Sx "Signed and encrypted messages with S/MIME"
8491 gives some details).
8492 This mode of operation is usually driven by the specialized form.
8494 When decrypting messages the account is derived from the recipient
8499 of the message, which are searched for addresses for which such
8501 \*(UA always uses the first address that matches,
8502 so if the same message is sent to more than one of the user's addresses
8503 using different encryption keys, decryption might fail.
8505 For signing and decryption purposes it is possible to use encrypted
8506 keys, and the pseudo-host(s)
8507 .Ql USER@HOST.smime-cert-key
8510 .Ql USER@HOST.smime-cert-cert
8511 for the certificate stored in the same file)
8512 will be used for performing any necessary password lookup,
8513 therefore the lookup can be automatized via the mechanisms described in
8514 .Sx "On URL syntax and credential lookup" .
8515 For example, the hypothetical address
8517 could be driven with a private key / certificate pair path defined in
8518 .Va \&\&smime-sign-cert-bob@exam.ple ,
8519 and needed passwords would then be looked up via the pseudo hosts
8520 .Ql bob@exam.ple.smime-cert-key
8522 .Ql bob@exam.ple.smime-cert-cert ) .
8523 To include intermediate certificates, use
8524 .Va smime-sign-include-certs .
8526 .Mx Va smime-sign-include-certs
8527 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
8528 \*(OP If used, this is supposed to a consist of a comma-separated list
8529 of files, each of which containing a single certificate in PEM format to
8530 be included in the S/MIME message in addition to the
8533 This can be used to include intermediate certificates of the certificate
8534 authority, in order to allow the receiver's S/MIME implementation to
8535 perform a verification of the entire certificate chain, starting from
8536 a local root certificate, over the intermediate certificates, down to the
8537 .Va smime-sign-cert .
8538 Even though top level certificates may also be included in the chain,
8539 they won't be used for the verification on the receiver's side.
8541 For the purpose of the mechanisms involved here,
8543 refers to the content of the internal variable
8545 (or, if that contains multiple addresses,
8548 .Ql USER@HOST.smime-include-certs
8549 will be used for performing password lookups for these certificates,
8550 shall they have been given one, therefore the lookup can be automatized
8551 via the mechanisms described in
8552 .Sx "On URL syntax and credential lookup" .
8554 .Mx Va smime-sign-message-digest
8555 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
8556 \*(OP Specifies the message digest to use when signing S/MIME messages.
8557 RFC 5751 mandates a default of
8559 Possible values are (case-insensitive and) in decreasing cipher strength:
8567 The actually available message digest algorithms depend on the
8568 cryptographic library that \*(UA uses.
8569 \*(OP Support for more message digest algorithms may be available
8570 through dynamic loading via, e.g.,
8571 .Xr EVP_get_digestbyname 3
8572 (OpenSSL) if \*(UA has been compiled to support this.
8573 Remember that for this
8575 refers to the variable
8577 (or, if that contains multiple addresses,
8582 \*(OB\*(OP To use the builtin SMTP transport, specify a SMTP URL in
8584 \*(ID For compatibility reasons a set
8586 is used in preference of
8590 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
8591 \*(OP Variable chain that controls the SMTP
8593 authentication method, possible values are
8599 as well as the \*(OPal methods
8605 method does not need any user credentials,
8607 requires a user name and all other methods require a user name and
8615 .Va smtp-auth-password
8617 .Va smtp-auth-user ) .
8622 .Va smtp-auth-USER@HOST :
8623 may override dependent on sender address in the variable
8626 .It Va smtp-auth-password
8627 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
8628 If the authentication method requires a password, but neither
8629 .Va smtp-auth-password
8631 .Va smtp-auth-password-USER@HOST
8633 \*(UA will ask for a password on the user's terminal.
8635 .It Va smtp-auth-password-USER@HOST
8637 .Va smtp-auth-password
8638 for specific values of sender addresses, dependent upon the variable
8641 .It Va smtp-auth-user
8642 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
8643 If the authentication method requires a user name, but neither
8646 .Va smtp-auth-user-USER@HOST
8648 \*(UA will ask for a user name on the user's terminal.
8650 .It Va smtp-auth-user-USER@HOST
8653 for specific values of sender addresses, dependent upon the variable
8657 .It Va smtp-hostname
8658 \*(OP\*(IN Normally \*(UA uses the variable
8660 to derive the necessary
8662 information in order to issue a
8669 can be used to use the
8671 from the SMTP account
8678 from the content of this variable (or, if that is the empty string,
8680 or the local hostname as a last resort).
8681 This often allows using an address that is itself valid but hosted by
8682 a provider other than which (in
8684 is about to send the message.
8685 Setting this variable also influences the generated
8688 .Mx Va smtp-use-starttls
8689 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
8690 \*(BO\*(OP Causes \*(UA to issue a
8692 command to make an SMTP
8694 session SSL/TLS encrypted, i.e., to enable transport layer security.
8698 .It Va spam-interface
8699 \*(OP In order to use any of the spam-related commands (like, e.g.,
8701 the desired spam interface must be defined by setting this variable.
8702 Please refer to the manual section
8704 for the complete picture of spam handling in \*(UA.
8705 All or none of the following interfaces may be available:
8707 .Bl -tag -width ".It Ql _ilte_"
8713 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
8715 Different to the generic filter interface \*(UA will automatically add
8716 the correct arguments for a given command and has the necessary
8717 knowledge to parse the program's output.
8720 will have been compiled into the \*(UA binary if
8725 Shall it be necessary to define a specific connection type (rather than
8726 using a configuration file for that), the variable
8728 can be used as in, e.g.,
8729 .Ql -d server.example.com -p 783 .
8730 It is also possible to specify a per-user configuration via
8732 Note that this interface does not inspect the
8734 flag of a message for the command
8738 generic spam filter support via freely configurable hooks.
8739 This interface is meant for programs like
8741 and requires according behaviour in respect to the hooks' exit
8742 status for at least the command
8745 meaning a message is spam,
8749 for unsure and any other return value indicating a hard error);
8750 since the hooks can include shell code snippets diverting behaviour
8751 can be intercepted as necessary.
8753 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
8756 .Va spamfilter-spam ;
8759 contains examples for some programs.
8760 The process environment of the hooks will have the variables
8761 .Ev NAIL_TMPDIR , TMPDIR
8763 .Ev NAIL_FILENAME_GENERATED
8765 Note that spam score support for
8767 is not supported unless the \*(OPtional regular expression support is
8769 .Va spamfilter-rate-scanscore
8776 \*(OP Messages that exceed this size will not be passed through to the
8778 .Va spam-interface .
8779 If unset or 0, the default of 420000 bytes is used.
8782 .It Va spamc-command
8783 \*(OP The path to the
8787 .Va spam-interface .
8788 Note that the path is not expanded, but used
8790 A fallback path will have been compiled into the \*(UA binary if the
8791 executable had been found during compilation.
8794 .It Va spamc-arguments
8795 \*(OP Even though \*(UA deals with most arguments for the
8798 automatically, it may at least sometimes be desirable to specify
8799 connection-related ones via this variable, e.g.,
8800 .Ql -d server.example.com -p 783 .
8804 \*(OP Specify a username for per-user configuration files for the
8806 .Va spam-interface .
8807 If this is set to the empty string then \*(UA will use the name of the
8816 .It Va spamfilter-ham , spamfilter-noham , \
8817 spamfilter-nospam , spamfilter-rate , spamfilter-spam
8818 \*(OP Command and argument hooks for the
8820 .Va spam-interface .
8823 contains examples for some programs.
8826 .It Va spamfilter-rate-scanscore
8827 \*(OP Because of the generic nature of the
8830 spam scores are not supported for it by default, but if the \*(OPtional
8831 regular expression support is available then setting this variable can
8832 be used to overcome this restriction.
8833 It is interpreted as follows: first a number (digits) is parsed that
8834 must be followed by a semicolon
8836 and an extended regular expression.
8837 Then the latter is used to parse the first output line of the
8839 hook, and, in case the evaluation is successful, the group that has been
8840 specified via the number is interpreted as a floating point scan score.
8844 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
8845 Enhanced Mail) for verification of of SSL/TLS server certificates.
8847 .Xr SSL_CTX_load_verify_locations 3
8848 for more information.
8852 \*(OP Specifies a file with CA certificates in PEM format for
8853 verification of SSL/TLS server certificates.
8855 .Xr SSL_CTX_load_verify_locations 3
8856 for more information.
8859 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
8860 \*(OP Variable chain that sets the file name for a SSL/TLS client
8861 certificate required by some servers.
8862 This is a direct interface to the
8866 function of the OpenSSL library, if available.
8868 .Mx Va ssl-cipher-list
8869 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
8870 \*(OP Specifies a list of ciphers for SSL/TLS connections.
8871 This is a direct interface to the
8875 function of the OpenSSL library, if available; see
8877 for more information.
8878 By default \*(UA does not set a list of ciphers, in effect using a
8880 specific cipher (protocol standards ship with a list of acceptable
8881 ciphers), possibly cramped to what the actually used SSL/TLS library
8882 supports \(en the manual section
8883 .Sx "An example configuration"
8884 also contains a SSL/TLS use case.
8887 .It Va ssl-config-file
8888 \*(OP If this variable is set \*(UA will call
8889 .Xr CONF_modules_load_file 3
8890 to allow OpenSSL to be configured according to the host system wide
8892 If a non-empty value is given then this will be used to specify the
8893 configuration file to be used instead of the global OpenSSL default;
8894 note that in this case it is an error if the file cannot be loaded.
8895 The application name will always be passed as
8900 \*(OP Specifies a file that contains a CRL in PEM format to use when
8901 verifying SSL/TLS server certificates.
8905 \*(OP Specifies a directory that contains files with CRLs in PEM format
8906 to use when verifying SSL/TLS server certificates.
8909 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
8910 \*(OP Variable chain that sets the file name for the private key of
8911 a SSL/TLS client certificate.
8912 If unset, the name of the certificate file is used.
8913 The file is expected to be in PEM format.
8914 This is a direct interface to the
8918 function of the OpenSSL library, if available.
8921 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
8922 \*(OB\*(OP Please use the newer and more flexible
8924 instead: if both values are set,
8926 will take precedence!
8927 Can be set to the following values, the actually used
8929 specification to which it is mapped is shown in parenthesis:
8931 .Pf ( Ql -ALL, TLSv1.2 ) ,
8933 .Pf ( Ql -ALL, TLSv1.1 ) ,
8935 .Pf ( Ql -ALL, TLSv1 )
8938 .Pf ( Ql -ALL, SSLv3 ) ;
8943 and thus includes the SSLv3 protocol.
8944 Note that SSLv2 is no longer supported at all.
8947 .It Va ssl-no-default-ca
8948 \*(BO\*(OP Do not load default CA locations to verify SSL/TLS server
8952 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
8953 \*(OP Specify the used SSL/TLS protocol.
8954 This is a direct interface to the
8958 function of the OpenSSL library, if available;
8959 otherwise an \*(UA internal parser is used which understands the
8960 following subset of (case-insensitive) command strings:
8966 as well as the special value
8968 Multiple specifications may be given via a comma-separated list which
8969 ignores any whitespace.
8972 plus prefix will enable a protocol, a
8974 minus prefix will disable it, so that
8976 will enable only the TLSv1.2 protocol.
8978 It depends upon the used TLS/SSL library which protocols are actually
8979 supported and which protocols are used if
8981 is not set, but note that SSLv2 is no longer supported at all and
8983 Especially for older protocols explicitly securing
8985 may be worthwile, see
8986 .Sx "An example configuration" .
8990 \*(OP Gives the pathname to an entropy daemon socket, see
8992 Not all SSL/TLS libraries support this.
8995 .It Va ssl-rand-file
8996 \*(OP Gives the filename to a file with random entropy data, see
8997 .Xr RAND_load_file 3 .
8998 If this variable is not set, or set to the empty string, or if the
8999 filename expansion failed, then
9000 .Xr RAND_file_name 3
9001 will be used to create the filename if, and only if,
9003 documents that the SSL PRNG is not yet sufficiently seeded.
9004 If \*(UA successfully seeded the SSL PRNG then it will update the file
9005 .Pf ( Xr RAND_write_file 3 ) .
9006 This variable is only used if
9008 is not set (or not supported by the SSL/TLS library).
9011 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
9012 \*(OP Variable chain that sets the action to be performed if an error
9013 occurs during SSL/TLS server certificate validation.
9014 Valid (case-insensitive) values are
9016 (fail and close connection immediately),
9018 (ask whether to continue on standard input),
9020 (show a warning and continue),
9022 (do not perform validation).
9028 If only set without an assigned value, then this setting inhibits the
9033 header fields that include obvious references to \*(UA.
9034 There are two pitfalls associated with this:
9035 First, the message id of outgoing messages is not known anymore.
9036 Second, an expert may still use the remaining information in the header
9037 to track down the originating mail user agent.
9042 suppression does not occur.
9047 (\*(OP) This specifies a comma-separated list of
9052 .Sx "On terminal control and line editor" ,
9053 escape commas with reverse solidus) to be used to overwrite or define
9055 Note that this variable will only be queried once at program startup and
9056 can thus only be specified in resource files or on the command line.
9059 String capabilities form
9061 pairs and are expected unless noted otherwise.
9062 Numerics have to be notated as
9064 where the number is expected in normal decimal notation.
9065 Finally, booleans do not have any value but indicate a true or false
9066 state simply by being defined or not; this indeed means that \*(UA
9067 does not support undefining an existing boolean.
9068 String capability values will undergo some expansions before use:
9069 for one notations like
9072 .Ql control-LETTER ,
9073 and for clarification purposes
9075 can be used to specify
9077 (the control notation
9079 could lead to misreadings when a left bracket follows, which it does for
9080 the standard CSI sequence);
9081 finally three letter octal sequences, as in
9084 To specify that a terminal supports 256-colours, and to define sequences
9085 that home the cursor and produce an audible bell, one might write:
9087 .Bd -literal -offset indent
9088 set termcap='Co#256,home=\eE[H,bel=^G'
9092 The following terminal capabilities are or may be meaningful for the
9093 operation of the builtin line editor or \*(UA in general:
9096 .Bl -tag -compact -width yay
9098 .It Cd colors Ns \0or Cd Co
9100 numeric capability specifying the maximum number of colours.
9101 Note that \*(UA does not actually care about the terminal beside that,
9102 but always emits ANSI / ISO 6429 escape sequences.
9105 .It Cd rmcup Ns \0or Cd te Ns \0/ Cd smcup Ns \0or Cd ti
9109 respectively: exit and enter the alternative screen
9111 effectively turning \*(UA into a fullscreen application.
9112 To disable that, set (at least) one to the empty string.
9114 .It Cd smkx Ns \0or Cd ks Ns \0/ Cd rmkx Ns \0or Cd ke
9118 respectively: enable and disable the keypad.
9119 This is always enabled if available, because it seems even keyboards
9120 without keypads generate other key codes for, e.g., cursor keys in that
9121 case, and only if enabled we see the codes that we are interested in.
9123 .It Cd ed Ns \0or Cd cd
9127 .It Cd clear Ns \0or Cd cl
9129 clear the screen and home cursor.
9130 (Will be simulated via
9135 .It Cd home Ns \0or Cd ho
9140 .It Cd el Ns \0or Cd ce
9142 clear to the end of line.
9143 (Will be simulated via
9145 plus repetitions of space characters.)
9147 .It Cd hpa Ns \0or Cd ch
9148 .Cd column_address :
9149 move the cursor (to the given column parameter) in the current row.
9150 (Will be simulated via
9156 .Cd carriage_return :
9157 move to the first column in the current row.
9158 The default builtin fallback is
9161 .It Cd cub1 Ns \0or Cd le
9163 move the cursor left one space (non-destructively).
9164 The default builtin fallback is
9167 .It Cd cuf1 Ns \0or Cd nd
9169 move the cursor right one space (non-destructively).
9170 The default builtin fallback is
9172 which is used by most terminals.
9180 Many more capabilities which describe key-sequences are documented for
9184 .It Va termcap-disable
9185 \*(OP Disable any interaction with a terminal control library.
9186 If set only some generic fallback builtins and possibly the content of
9188 describe the terminal to \*(UA.
9190 that this variable will only be queried once at program startup and can
9191 thus only be specified in resource files or on the command line.
9195 If defined, gives the number of lines of a message to be displayed
9198 if unset, the first five lines are printed, if set to 0 the variable
9201 If the value is negative then its absolute value will be used for right
9204 height; (shifting bitwise is like dividing algorithmically, but since
9205 it takes away bits the value decreases pretty fast).
9209 \*(BO If set then the
9211 command series will strip adjacent empty lines and quotations.
9215 The character set of the terminal \*(UA operates on,
9216 and the one and only supported character set that \*(UA can use if no
9217 character set conversion capabilities have been compiled into it,
9218 in which case it defaults to ISO-8859-1 unless it can deduce a value
9222 It defaults to UTF-8 if conversion is available.
9223 Refer to the section
9224 .Sx "Character sets"
9225 for the complete picture about character sets.
9228 .It Va typescript-mode
9229 \*(BO A special multiplex variable that disables all variables and
9230 settings which result in behaviour that interferes with running \*(UA in
9233 .Va colour-disable ,
9234 .Va line-editor-disable
9235 and (before startup completed only)
9236 .Va termcap-disable .
9237 Unsetting it does not restore the former state of the covered settings.
9241 For a safety-by-default policy \*(UA sets its process
9245 but this variable can be used to override that:
9246 set it to an empty value to do not change the (current) setting,
9247 otherwise the process file mode creation mask is updated to the new value.
9248 Child processes inherit the process file mode creation mask.
9251 .It Va user-HOST , user
9252 \*(IN Variable chain that sets a global fallback user name, which is
9253 used in case none has been given in the protocol and account-specific
9255 This variable defaults to the name of the user who runs \*(UA.
9259 \*(BO Setting this enables upward compatibility with \*(UA
9260 version 15.0 in respect to which configuration options are available and
9261 how they are handled.
9262 This manual uses \*(IN and \*(OU to refer to the new and the old way of
9263 doing things, respectively.
9267 \*(BO This setting, also controllable via the command line option
9269 causes \*(UA to be more verbose, e.g., it will display obsoletion
9270 warnings and SSL/TLS certificate chains.
9271 Even though marked \*(BO this option may be set twice in order to
9272 increase the level of verbosity even more, in which case even details of
9273 the actual message delivery and protocol conversations are shown.
9276 is sufficient to disable verbosity as such.
9282 .It Va version , version-major , version-minor , version-update
9283 \*(RO \*(UA version information: the first variable contains a string
9284 containing the complete version identification, the latter three contain
9285 only digits: the major, minor and update version numbers.
9286 The output of the command
9288 will include this information.
9291 .It Va writebackedited
9292 If this variable is set messages modified using the
9296 commands are written back to the current folder when it is quit;
9297 it is only honoured for writable folders in MBOX format, though.
9298 Note that the editor will be pointed to the raw message content in that
9299 case, i.e., neither MIME decoding nor decryption will have been
9300 performed, and proper RFC 4155
9302 quoting of newly added or edited content is also left as an excercise to
9306 .\" }}} (INTERNAL VARIABLES)
9309 .\" .Sh ENVIRONMENT {{{
9313 .Dq environment variable
9314 should be considered an indication that these variables are either
9315 standardized as vivid parts of process environments, or that they are
9316 commonly found in there.
9317 The process environment is inherited from the
9319 once \*(UA is started, and unless otherwise explicitly noted handling of
9320 the following variables transparently integrates into that of the
9321 .Sx "INTERNAL VARIABLES"
9322 from \*(UA's point of view.
9323 This means that, e.g., they can be managed via
9327 causing automatic program environment updates (to be inherited by
9328 newly created child processes).
9331 In order to transparently integrate other environment variables equally
9332 they need to be imported (linked) with the command
9334 This command can also be used to set and unset non-integrated
9335 environment variables from scratch, sufficient system support provided.
9336 The following example, applicable to a POSIX shell, sets the
9338 environment variable for \*(UA only, and beforehand exports the
9340 in order to affect any further processing in the running shell:
9342 .Bd -literal -offset indent
9343 $ EDITOR="vim -u ${HOME}/.vimrc"
9345 $ COLUMNS=80 \*(uA -R
9348 .Bl -tag -width ".It Ev BaNg"
9351 The user's preferred width in column positions for the terminal screen
9353 Queried and used once on program startup, actively managed for child
9354 processes and the MLE (see
9355 .Sx "On terminal control and line editor" )
9356 in interactive mode thereafter.
9360 The name of the (mailbox)
9362 to use for saving aborted messages if
9364 is set; this defaults to
9371 is set no output will be generated, otherwise the contents of the file
9376 Pathname of the text editor to use in the
9380 .Sx "COMMAND ESCAPES" .
9381 A default editor is used if this value is not defined.
9385 The user's home directory.
9386 This variable is only used when it resides in the process environment.
9393 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
9397 .Sx "Character sets" .
9401 The user's preferred number of lines on a page or the vertical screen
9402 or window size in lines.
9403 Queried and used once on program startup, actively managed for child
9404 processes in interactive mode thereafter.
9408 Pathname of the directory lister to use in the
9410 command when operating on local mailboxes.
9413 (path search through
9418 Upon startup \*(UA will actively ensure that this variable refers to the
9419 name of the user who runs \*(UA, in order to be able to pass a verified
9420 name to any newly created child process.
9424 Is used as the users
9426 .Sx "primary system mailbox"
9430 This is assumed to be an absolute pathname.
9434 \*(OP Overrides the default path search for
9435 .Sx "The Mailcap files" ,
9436 which is defined in the standard RFC 1524 as
9437 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
9438 .\" TODO we should have a mailcaps-default virtual RDONLY option!
9439 (\*(UA makes it a configuration option, however.)
9440 Note this is not a search path, but a path search.
9444 Is used as a startup file instead of
9447 When \*(UA scripts are invoked on behalf of other users,
9448 either this variable should be set to
9452 command line option should be used in order to avoid side-effects from
9453 reading their configuration files.
9454 This variable is only used when it resides in the process environment.
9458 The name of the users mbox file.
9459 A logical subset of the special
9461 .Sx "filename transformations"
9462 that are documented for
9467 The fallback default is
9474 .Sx "secondary mailbox"
9475 is used as the file to save messages from the
9477 .Sx "primary system mailbox"
9478 that have been read.
9480 .Sx "Message states" .
9483 .It Ev NAIL_NO_SYSTEM_RC
9484 If this variable is set then reading of
9486 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
9487 had been started up with the option
9489 This variable is only used when it resides in the process environment.
9493 \*(IN\*(OP This variable overrides the default location of the user's
9499 Pathname of the program to use for backing the command
9503 variable enforces usage of a pager for output.
9504 The default paginator is
9506 (path search through
9509 \*(UA inspects the contents of this variable: if its contains the string
9511 then a non-existing environment variable
9518 dependent on whether terminal control support is available and whether
9519 that supports full (alternative) screen mode or not (also see
9520 .Sx "On terminal control and line editor" ) .
9524 will optionally be set to
9531 A colon-separated list of directories that is searched by the shell when
9532 looking for commands, e.g.,
9533 .Ql /bin:/usr/bin:/usr/local/bin .
9536 .It Ev POSIXLY_CORRECT
9537 This variable is automatically looked for upon startup, see
9543 The shell to use for the commands
9548 .Sx "COMMAND ESCAPES"
9549 and when starting subprocesses.
9550 A default shell is used if this environment variable is not defined.
9553 .It Ev SOURCE_DATE_EPOCH
9554 If set, this specifies a time in seconds since the Unix epoch
9555 (1970-01-01) to be used in place of the current time.
9556 This is for the sake of reproduceability of tests, to be used during
9557 development or by software packagers.
9561 \*(OP The terminal type for which output is to be prepared.
9562 For extended colour and font control please refer to
9563 .Sx "Coloured display" ,
9564 and for terminal management in general to
9565 .Sx "On terminal control and line editor" .
9569 Used as directory for temporary files instead of
9572 This variable is only used when it resides in the process environment.
9578 (see there), but this variable is not standardized, should therefore not
9579 be used, and is only corrected if already set.
9583 Pathname of the text editor to use in the
9587 .Sx "COMMAND ESCAPES" .
9595 .Bl -tag -width ".It Pa BaNg"
9597 File giving initial commands.
9600 System wide initialization file.
9604 \*(OP Personal MIME type handler definition file, see
9605 .Sx "The Mailcap files" .
9606 (RFC 1524 location, the actual path is a configuration option.)
9610 \*(OP System wide MIME type handler definition file, see
9611 .Sx "The Mailcap files" .
9612 (RFC 1524 location, the actual path is a configuration option.)
9615 .It Pa ~/.mime.types
9616 Personal MIME types, see
9617 .Sx "The mime.types files" .
9620 .It Pa /etc/mime.types
9621 System wide MIME types, see
9622 .Sx "The mime.types files" .
9626 \*(IN\*(OP The default location of the users
9628 file \(en the section
9629 .Sx "The .netrc file"
9630 documents the file format.
9633 .\" .Ss "The mime.types files" {{{
9634 .Ss "The mime.types files"
9636 When sending messages \*(UA tries to determine the content type of all
9638 When displaying message content or attachments \*(UA uses the content
9639 type to decide whether it can directly display data or whether it needs
9640 to deal with content handlers.
9641 It learns about M(ultipurpose) I(nternet) M(ail) E(xtensions) types and
9642 how to treat them by reading
9644 files, the loading of which can be controlled by setting the variable
9645 .Va mimetypes-load-control .
9648 can also be used to deal with MIME types.)
9650 files have the following syntax:
9653 .Dl type/subtype extension [extension ...]
9658 are strings describing the file contents, and one or multiple
9660 s, separated by whitespace, name the part of a filename starting after
9661 the last dot (of interest).
9662 Comments may be introduced anywhere on a line with a number sign
9664 causing the remaining line to be discarded.
9666 \*(UA also supports an extended, non-portable syntax in specially
9667 crafted files, which can be loaded via the alternative value syntax of
9668 .Va mimetypes-load-control
9669 and prepends an optional
9673 .Dl [type-marker ]type/subtype extension [extension ...]
9676 The following type markers are supported:
9679 .Bl -tag -compact -width ".It Ar _n_u"
9681 Treat message parts with this content as plain text.
9686 Treat message parts with this content as HTML tagsoup.
9687 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
9688 the content as plain text instead.
9692 but instead of falling back to plain text require an explicit content
9693 handler to be defined.
9698 for sending messages:
9700 .Va mime-allow-text-controls ,
9701 .Va mimetypes-load-control .
9702 For reading etc. messages:
9703 .Sx "HTML mail and MIME attachments" ,
9704 .Sx "The Mailcap files" ,
9706 .Va mime-counter-evidence ,
9707 .Va mimetypes-load-control ,
9708 .Va pipe-TYPE/SUBTYPE ,
9709 .Va pipe-EXTENSION .
9712 .\" .Ss "The Mailcap files" {{{
9713 .Ss "The Mailcap files"
9715 .\" TODO MAILCAP DISABLED
9716 .Sy This feature is not available in v14.9.0, sorry!
9718 .Dq User Agent Configuration Mechanism
9719 which \*(UA \*(OPally supports.
9720 It defines a file format to be used to inform mail user agent programs
9721 about the locally-installed facilities for handling various data
9722 formats, i.e., about commands and how they can be used to display, edit
9723 etc. MIME part contents, as well as a default path search that includes
9724 multiple possible locations of
9728 environment variable that can be used to overwrite that (repeating here
9729 that it is not a search path, but instead a path search specification).
9730 Any existing files will be loaded in sequence, appending any content to
9731 the list of MIME type handler directives.
9735 files consist of a set of newline separated entries.
9736 Comment lines start with a number sign
9738 (in the first column!) and are ignored.
9739 Empty lines are also ignored.
9740 All other lines form individual entries that must adhere to the syntax
9742 To extend a single entry (not comment) its line can be continued on
9743 follow lines if newline characters are
9745 by preceding them with the reverse solidus character
9747 The standard does not specify how leading whitespace of follow lines
9748 is to be treated, therefore \*(UA retains it.
9752 entries consist of a number of semicolon
9754 separated fields, and the reverse solidus
9756 character can be used to escape any following character including
9757 semicolon and itself.
9758 The first two fields are mandatory and must occur in the specified
9759 order, the remaining fields are optional and may appear in any order.
9760 Leading and trailing whitespace of content is ignored (removed).
9763 The first field defines the MIME
9765 the entry is about to handle (case-insensitively, and no reverse solidus
9766 escaping is possible in this field).
9767 If the subtype is specified as an asterisk
9769 the entry is meant to match all subtypes of the named type, e.g.,
9771 would match any audio type.
9772 The second field defines the shell command which shall be used to
9774 MIME parts of the given type; it is implicitly called the
9781 shell commands message (MIME part) data is passed via standard input
9782 unless the given shell command includes one or more instances of the
9785 in which case these instances will be replaced with a temporary filename
9786 and the data will have been stored in the file that is being pointed to.
9789 shell commands data is assumed to be generated on standard output unless
9790 the given command includes (one ore multiple)
9792 In any case any given
9794 format is replaced with a(n already) properly quoted filename.
9795 Note that when a command makes use of a temporary file via
9797 then \*(UA will remove it again, as if the
9798 .Cd x-mailx-tmpfile ,
9799 .Cd x-mailx-tmpfile-fill
9801 .Cd x-mailx-tmpfile-unlink
9802 flags had been set; see below for more.
9805 The optional fields either define a shell command or an attribute (flag)
9806 value, the latter being a single word and the former being a keyword
9807 naming the field followed by an equals sign
9809 succeeded by a shell command, and as usual for any
9811 content any whitespace surrounding the equals sign will be removed, too.
9812 Optional fields include the following:
9815 .Bl -tag -width ".It Cd BaNg"
9817 A program that can be used to compose a new body or body part in the
9824 field, but is to be used when the composing program needs to specify the
9826 header field to be applied to the composed data.
9830 A program that can be used to edit a body or body part in the given
9835 A program that can be used to print a message or body part in the given
9840 Specifies a program to be run to test some condition, e.g., the machine
9841 architecture, or the window system in use, to determine whether or not
9842 this mailcap entry applies.
9843 If the test fails, a subsequent mailcap entry should be sought; also see
9844 .Cd x-mailx-test-once .
9846 .It Cd needsterminal
9847 This flag field indicates that the given shell command must be run on
9848 an interactive terminal.
9849 \*(UA will temporarily release the terminal to the given command in
9850 interactive mode, in non-interactive mode this entry will be entirely
9851 ignored; this flag implies
9852 .Cd x-mailx-noquote .
9854 .It Cd copiousoutput
9855 A flag field which indicates that the output of the
9857 command will be an extended stream of textual output that can be
9858 (re)integrated into \*(UA's normal visual display.
9859 It is mutually exclusive with
9862 .Cd x-mailx-always .
9864 .It Cd textualnewlines
9865 A flag field which indicates that this type of data is line-oriented and
9868 all newlines should be converted to canonical form (CRLF) before
9869 encoding, and will be in that form after decoding.
9873 This field gives a file name format, in which
9875 will be replaced by a random string, the joined combination of which
9876 will be used as the filename denoted by
9877 .Ev NAIL_FILENAME_TEMPORARY .
9878 One could specify that a GIF file being passed to an image viewer should
9879 have a name ending in
9882 .Ql nametemplate=%s.gif .
9883 Note that \*(UA ignores the name template unless that solely specifies
9884 a filename suffix that consists of (ASCII) alphabetic and numeric
9885 characters, the underscore and dot only.
9888 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
9889 icon to be used to visually denote the presence of this kind of data.
9890 This field is not used by \*(UA.
9893 A textual description that describes this type of data.
9895 .It Cd x-mailx-always
9896 Extension flag field that denotes that the given
9898 command shall be executed even if multiple messages will be displayed
9900 Normally messages which require external viewers that produce output
9901 which does not integrate into \*(UA's visual display (i.e., do not have
9903 set) have to be addressed directly and individually.
9904 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
9907 .It Cd x-mailx-even-if-not-interactive
9908 An extension flag test field \(em by default handlers without
9910 are entirely ignored in non-interactive mode, but if this flag is set
9911 then their use will be considered.
9912 It is an error if this flag is set for commands that use the flag
9915 .It Cd x-mailx-noquote
9916 An extension flag field that indicates that even a
9919 command shall not be used to generate message quotes
9920 (as it would be by default).
9922 .It Cd x-mailx-async
9923 Extension flag field that denotes that the given
9925 command shall be executed asynchronously, without blocking \*(UA.
9926 Cannot be used in conjunction with
9929 .It Cd x-mailx-test-once
9930 Extension flag which denotes whether the given
9932 command shall be evaluated once only and the (boolean) result be cached.
9933 This is handy if some global unchanging condition is to be queried, like
9934 .Dq running under the X Window System .
9936 .It Cd x-mailx-tmpfile
9937 Extension flag field that requests creation of a zero-sized temporary
9938 file, the name of which is to be placed in the environment variable
9939 .Ev NAIL_FILENAME_TEMPORARY .
9940 It is an error to use this flag with commands that include a
9944 .It Cd x-mailx-tmpfile-fill
9945 Normally the MIME part content is passed to the handler via standard
9946 input; if this flag is set then the data will instead be written into
9948 .Cd x-mailx-tmpfile .
9949 In order to cause deletion of the temporary file you will have to set
9950 .Cd x-mailx-tmpfile-unlink
9952 It is an error to use this flag with commands that include a
9956 .It Cd x-mailx-tmpfile-unlink
9957 Extension flag field that requests that the temporary file shall be
9958 deleted automatically when the command loop is entered again at latest.
9959 (Do not use this for asynchronous handlers.)
9960 It is an error to use this flag with commands that include a
9962 format, or without also setting
9965 .Cd x-mailx-tmpfile-fill .
9967 .It Cd x-mailx-tmpfile-keep
9970 implies the three tmpfile related flags above, but if you want, e.g.,
9972 and deal with the temporary file yourself, you can add in this flag to
9974 .Cd x-mailx-tmpfile-unlink .
9979 The standard includes the possibility to define any number of additional
9980 entry fields, prefixed by
9982 Flag fields apply to the entire
9984 entry \(em in some unusual cases, this may not be desirable, but
9985 differentiation can be accomplished via separate entries, taking
9986 advantage of the fact that subsequent entries are searched if an earlier
9987 one does not provide enough information.
9990 command needs to specify the
9994 command shall not, the following will help out the latter (with enabled
9998 level \*(UA will show information about handler evaluation):
10000 .Bd -literal -offset indent
10001 application/postscript; ps-to-terminal %s; needsterminal
10002 application/postscript; ps-to-terminal %s; compose=idraw %s
10006 In fields any occurrence of the format string
10008 will be replaced by the
10011 Named parameters from the
10013 field may be placed in the command execution line using
10015 followed by the parameter name and a closing
10018 The entire parameter should appear as a single command line argument,
10019 regardless of embedded spaces; thus:
10021 .Bd -literal -offset indent
10023 Content-type: multipart/mixed; boundary=42
10026 multipart/*; /usr/local/bin/showmulti \e
10027 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
10029 # Executed shell command
10030 /usr/local/bin/showmulti multipart/mixed 42
10034 .\" TODO v15: Mailcap: %n,%F
10035 Note that \*(UA does not support handlers for multipart MIME parts as
10036 shown in this example (as of today).
10037 \*(UA does not support the additional formats
10041 An example file, also showing how to properly deal with the expansion of
10043 which includes any quotes that are necessary to make it a valid shell
10044 argument by itself and thus will cause undesired behaviour when placed
10045 in additional user-provided quotes:
10047 .Bd -literal -offset indent
10049 text/richtext; richtext %s; copiousoutput
10051 text/x-perl; perl -cWT %s
10053 application/pdf; \e
10055 trap "rm -f ${infile}" EXIT\e; \e
10056 trap "exit 75" INT QUIT TERM\e; \e
10058 x-mailx-async; x-mailx-tmpfile-keep
10060 application/*; echo "This is \e"%t\e" but \e
10061 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
10062 copiousoutput; x-mailx-noquote
10067 .Sx "HTML mail and MIME attachments" ,
10068 .Sx "The mime.types files" ,
10071 .Va mime-counter-evidence ,
10072 .Va pipe-TYPE/SUBTYPE ,
10073 .Va pipe-EXTENSION .
10076 .\" .Ss "The .netrc file" {{{
10077 .Ss "The .netrc file"
10081 file contains user credentials for machine accounts.
10082 The default location in the user's
10084 directory may be overridden by the
10086 environment variable.
10087 The file consists of space, tabulator or newline separated tokens.
10088 \*(UA implements a parser that supports a superset of the original BSD
10089 syntax, but users should nonetheless be aware of portability glitches
10090 of that file format, shall their
10092 be usable across multiple programs and platforms:
10095 .Bl -bullet -compact
10097 BSD does not support single, but only double quotation marks, e.g.,
10098 .Ql password="pass with spaces" .
10100 BSD (only?) supports escaping of single characters via a reverse solidus
10101 (e.g., a space can be escaped via
10103 in- as well as outside of a quoted string.
10105 BSD does not require a final quotation mark of the last user input token.
10107 The original BSD (Berknet) parser also supported a format which allowed
10108 tokens to be separated with commas \(en whereas at least Hewlett-Packard
10109 still seems to support this syntax, \*(UA does not!
10111 As a non-portable extension some widely-used programs support
10112 shell-style comments: if an input line starts, after any amount of
10113 whitespace, with a number sign
10115 then the rest of the line is ignored.
10117 Whereas other programs may require that the
10119 file is accessible by only the user if it contains a
10121 token for any other
10125 \*(UA will always require these strict permissions.
10129 Of the following list of supported tokens \*(UA only uses (and caches)
10134 At runtime the command
10136 can be used to control \*(UA's
10140 .Bl -tag -width ".It Cd BaNg"
10141 .It Cd machine Ar name
10142 The hostname of the entries' machine, lowercase-normalized by \*(UA
10144 Any further file content, until either end-of-file or the occurrence
10149 first-class token is bound (only related) to the machine
10152 As an extension that should not be the cause of any worries
10153 \*(UA supports a single wildcard prefix for
10155 .Bd -literal -offset indent
10156 machine *.example.com login USER password PASS
10157 machine pop3.example.com login USER password PASS
10158 machine smtp.example.com login USER password PASS
10164 .Ql pop3.example.com ,
10168 .Ql local.smtp.example.com .
10169 Note that in the example neither
10170 .Ql pop3.example.com
10172 .Ql smtp.example.com
10173 will be matched by the wildcard, since the exact matches take
10174 precedence (it is however faster to specify it the other way around).
10177 This is the same as
10179 except that it is a fallback entry that is used shall none of the
10180 specified machines match; only one default token may be specified,
10181 and it must be the last first-class token.
10183 .It Cd login Ar name
10184 The user name on the remote machine.
10186 .It Cd password Ar string
10187 The user's password on the remote machine.
10189 .It Cd account Ar string
10190 Supply an additional account password.
10191 This is merely for FTP purposes.
10193 .It Cd macdef Ar name
10195 A macro is defined with the specified
10197 it is formed from all lines beginning with the next line and continuing
10198 until a blank line is (consecutive newline characters are) encountered.
10201 entries cannot be utilized by multiple machines, too, but must be
10202 defined following the
10204 they are intended to be used with.)
10207 exists, it is automatically run as the last step of the login process.
10208 This is merely for FTP purposes.
10215 .\" .Sh EXAMPLES {{{
10218 .\" .Ss "An example configuration" {{{
10219 .Ss "An example configuration"
10221 .Bd -literal -offset indent
10222 # This example assumes v15.0 compatibility mode
10225 # Where are the up-to-date SSL certificates?
10226 #set ssl-ca-dir=/etc/ssl/certs
10227 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
10229 # (Since we manage up-to-date ones explicitly, do not use any,
10230 # possibly outdated, default certificates shipped with OpenSSL)
10231 set ssl-no-default-ca
10233 # Do not use protocols older than TLS v1.2.
10234 # Change this only when the remote server does not support it:
10235 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
10236 # such explicit exceptions, then
10237 set ssl-protocol='-ALL,+TLSv1.2'
10239 # Explicitly define the list of ciphers, which may improve security,
10240 # especially with protocols older than TLS v1.2. See ciphers(1).
10241 # Including "@STRENGTH" will sort the final list by algorithm strength.
10242 # In reality it is possibly best to only use ssl-cipher-list-HOST
10243 # (or -USER@HOST), as necessary, again..
10244 set ssl-cipher-list=TLSv1.2:!aNULL:!eNULL:!MEDIUM:!LOW:!EXPORT:@STRENGTH
10245 # ALL:!aNULL:!MEDIUM:!LOW:!MD5:!RC4:!EXPORT:@STRENGTH
10247 # Request strict transport security checks!
10248 set ssl-verify=strict
10250 # Essential setting: select allowed character sets
10251 set sendcharsets=utf-8,iso-8859-1
10253 # A very kind option: when replying to a message, first try to
10254 # use the same encoding that the original poster used herself!
10255 set reply-in-same-charset
10257 # When replying to or forwarding a message the comment and name
10258 # parts of email addresses are removed unless this variable is set
10261 # When sending messages, wait until the Mail-Transfer-Agent finishs.
10262 # Only like this you will be able to see errors reported through the
10263 # exit status of the MTA (including the builtin SMTP one)!
10266 # Only use builtin MIME types, no mime.types(5) files
10267 set mimetypes-load-control
10269 # Default directory where we act in (relative to $HOME)
10271 # A leading "+" (often) means: under *folder*
10272 # *record* is used to save copies of sent messages
10273 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.txt
10275 # Make "file mymbox" and "file myrec" go to..
10276 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
10278 # Not really optional, e.g., for S/MIME
10279 set from='Your Name <address@exam.ple>'
10281 # It may be necessary to set hostname and/or smtp-hostname
10282 # if the "SERVER" of mta and "domain" of from do not match.
10283 # The `urlencode' command can be used to encode USER and PASS
10284 set mta=(smtps?|submission)://[USER[:PASS]@]SERVER[:PORT] \e
10285 smtp-auth=login/plain... \e
10288 # Never refuse to start into interactive mode, and more
10290 colour-pager crt= \e
10291 followup-to followup-to-honour=ask-yes \e
10292 history-file=+.\*(uAhist history-size=-1 history-gabby \e
10293 mime-counter-evidence=0xE \e
10294 prompt='[\e${-account-name} \e${-mailbox-display}]? ' \e
10295 reply-to-honour=ask-yes \e
10298 # Only include the selected header fields when typing messages
10299 headerpick type retain add from_ date from to cc subject \e
10300 message-id mail-followup-to reply-to
10301 # ...when forwarding messages
10302 headerpick forward retain add subject date from to cc
10303 # ...when saving message, etc.
10304 #headerpick save ignore add ^Original-.*$ ^X-.*$
10306 # Some mailing lists
10307 mlist '@xyz-editor\e.xyz$' '@xyzf\e.xyz$'
10308 mlsubscribe '^xfans@xfans\e.xyz$'
10310 # A real life example of a very huge free mail provider
10312 set folder=~/spool/XooglX inbox=+syste.mbox sent=+sent
10313 set from='Your Name <address@examp.ple>'
10314 set mta=smtp://USER:PASS@smtp.gmXil.com smtp-use-starttls
10317 # Here is a pretty large one which does not allow sending mails
10318 # if there is a domain name mismatch on the SMTP protocol level,
10319 # which would bite us if the value of from does not match, e.g.,
10320 # for people who have a sXXXXeforge project and want to speak
10321 # with the mailing list under their project account (in from),
10322 # still sending the message through their normal mail provider
10324 set folder=~/spool/XandeX inbox=+syste.mbox sent=+sent
10325 set from='Your Name <address@exam.ple>'
10326 set mta=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
10327 hostname=yaXXex.com smtp-hostname=
10330 # Create some new commands so that, e.g., `ls /tmp' will..
10331 wysh ghost lls '!ls ${LS_COLOR_FLAG} -aFlrS'
10332 wysh ghost llS '!ls ${LS_COLOR_FLAG} -aFlS'
10333 wysh ghost ls '!ls ${LS_COLOR_FLAG} -aFrS'
10334 wysh ghost lS '!ls ${LS_COLOR_FLAG} -aFS'
10335 wysh ghost lla '!ls ${LS_COLOR_FLAG} -aFlr'
10336 wysh ghost llA '!ls ${LS_COLOR_FLAG} -aFl'
10337 wysh ghost la '!ls ${LS_COLOR_FLAG} -aFr'
10338 wysh ghost lA '!ls ${LS_COLOR_FLAG} -aF'
10339 wysh ghost ll '!ls ${LS_COLOR_FLAG} -aFltr'
10340 wysh ghost lL '!ls ${LS_COLOR_FLAG} -aFlt'
10341 wysh ghost l '!ls ${LS_COLOR_FLAG} -aFtr'
10342 wysh ghost L '!ls ${LS_COLOR_FLAG} -aFt'
10344 # We do not support gpg(1) directly yet. But simple --clearsign'd
10345 # message parts can be dealt with as follows:
10347 wysh set pipe-text/plain=$'@*#++=@\e
10348 < "${NAIL_FILENAME_TEMPORARY}" awk \e
10349 -v TMPFILE="${NAIL_FILENAME_TEMPORARY}" \e'\e
10351 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/{\e
10354 print "--- GPG --verify ---";\e
10355 system("gpg --verify " TMPFILE " 2>&1");\e
10356 print "--- GPG --verify ---";\e
10360 /^-----BEGIN PGP SIGNATURE-----/,\e
10361 /^-----END PGP SIGNATURE-----/{\e
10371 !printf 'Key IDs to gpg --recv-keys: ';\e
10373 gpg --recv-keys ${keyids};
10379 When storing passwords in
10381 appropriate permissions should be set on this file with
10382 .Ql $ chmod 0600 \*(ur .
10385 is available user credentials can be stored in the central
10387 file instead; e.g., here is a different version of the example account
10388 that sets up SMTP and POP3:
10390 .Bd -literal -offset indent
10392 set folder=~/spool/XandeX inbox=+syste.mbox sent=+sent
10393 set from='Your Name <address@exam.ple>'
10395 # Load an encrypted ~/.netrc by uncommenting the next line
10396 #set netrc-pipe='gpg -qd ~/.netrc.pgp'
10398 set mta=smtps://smtp.yXXXXx.ru:465 \e
10399 smtp-hostname= hostname=yXXXXx.com
10400 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
10401 ghost xp fi pop3s://pop.yXXXXx.ru
10410 .Bd -literal -offset indent
10411 machine *.yXXXXx.ru login USER password PASS
10415 This configuration should now work just fine:
10418 .Dl $ echo text | \*(uA -vv -AXandeX -s Subject user@exam.ple
10421 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
10422 .Ss "Signed and encrypted messages with S/MIME"
10424 \*(OP S/MIME provides two central mechanisms:
10425 message signing and message encryption.
10426 A signed message contains some data in addition to the regular text.
10427 The data can be used to verify that the message was sent using a valid
10428 certificate, that the sender's address in the message header matches
10429 that in the certificate, and that the message text has not been altered.
10430 Signing a message does not change its regular text;
10431 it can be read regardless of whether the recipient's software is able to
10435 It is thus usually possible to sign all outgoing messages if so desired.
10436 Encryption, in contrast, makes the message text invisible for all people
10437 except those who have access to the secret decryption key.
10438 To encrypt a message, the specific recipient's public encryption key
10440 It is therefore not possible to send encrypted mail to people unless their
10441 key has been retrieved from either previous communication or public key
10443 A message should always be signed before it is encrypted.
10444 Otherwise, it is still possible that the encrypted message text is
10448 A central concept to S/MIME is that of the certification authority (CA).
10449 A CA is a trusted institution that issues certificates.
10450 For each of these certificates it can be verified that it really
10451 originates from the CA, provided that the CA's own certificate is
10453 A set of CA certificates is usually delivered with OpenSSL and installed
10455 If you trust the source of your OpenSSL software installation,
10456 this offers reasonable security for S/MIME on the Internet.
10458 .Va smime-no-default-ca
10459 to avoid using the default certificate and point
10463 to a trusted pool of certificates.
10464 In general, a certificate cannot be more secure than the method its CA
10465 certificate has been retrieved with.
10468 The first thing you need for participating in S/MIME message exchange is
10469 your personal certificate, including a private key.
10470 The certificate contains public information, in particular your name and
10471 your email address(es), and the public key that is used by others to
10472 encrypt messages for you,
10473 and to verify signed messages they supposedly received from you.
10474 The certificate is included in each signed message you send.
10475 The private key must be kept secret.
10476 It is used to decrypt messages that were previously encrypted with your
10477 public key, and to sign messages.
10480 For personal use it is recommended that you get a S/MIME certificate
10481 from one of the major CAs on the Internet using your WWW browser.
10482 Many CAs offer such certificates for free.
10484 .Lk https://www.CAcert.org
10485 which issues client and server certificates to members of their
10486 community for free; their root certificate
10487 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
10488 is often not in the default set of trusted CA root certificates, though,
10489 which means you will have to download their root certificate separately
10490 and ensure it is part of our S/MIME certificate validation chain by
10493 or as a vivid member of the
10494 .Va smime-ca-file .
10495 But let us take a step-by-step tour on how to setup S/MIME with
10496 a certificate from CAcert.org despite this situation!
10499 First of all you will have to become a member of the CAcert.org
10500 community, simply by registrating yourself via the web interface.
10501 Once you are, create and verify all email addresses you want to be able
10502 to create signed and encrypted messages for/with using the corresponding
10503 entries of the web interface.
10504 Now ready to create S/MIME certificates, so let us create a new
10505 .Dq client certificate ,
10506 ensure to include all email addresses that should be covered by the
10507 certificate in the following web form, and also to use your name as the
10511 Create a private key and a certificate request on your local computer
10512 (please see the manual pages of the used commands for more in-depth
10513 knowledge on what the used arguments etc. do):
10516 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
10519 Afterwards copy-and-paste the content of
10521 into the certificate-request (CSR) field of the web form on the
10522 CAcert.org website (you may need to unfold some
10523 .Dq advanced options
10524 to see the corresponding text field).
10525 This last step will ensure that your private key (which never left your
10526 box) and the certificate belong together (through the public key that
10527 will find its way into the certificate via the certificate-request).
10528 You are now ready and can create your CAcert certified certificate.
10529 Download and store or copy-and-paste it as
10534 In order to use your new S/MIME setup a combined private key/public key
10535 (certificate) file has to be created:
10538 .Dl cat key.pem pub.crt > ME@HERE.com.paired
10541 This is the file \*(UA will work with.
10542 If you have created your private key with a passphrase then \*(UA will
10543 ask you for it whenever a message is signed or decrypted.
10544 Set the following variables to henceforth use S/MIME (setting
10546 is of interest for verification only):
10548 .Bd -literal -offset indent
10549 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
10550 smime-sign-cert=ME@HERE.com.paired \e
10551 smime-sign-message-digest=SHA256 \e
10556 From each signed message you send, the recipient can fetch your
10557 certificate and use it to send encrypted mail back to you.
10558 Accordingly if somebody sends you a signed message, you can do the same,
10561 command to check the validity of the certificate.
10564 Variables of interest for S/MIME signing:
10566 .Va smime-ca-file ,
10567 .Va smime-crl-dir ,
10568 .Va smime-crl-file ,
10569 .Va smime-no-default-ca ,
10571 .Va smime-sign-cert ,
10572 .Va smime-sign-include-certs
10574 .Va smime-sign-message-digest .
10577 After it has been verified save the certificate via
10579 and tell \*(UA that it should use it for encryption for further
10580 communication with that somebody:
10582 .Bd -literal -offset indent
10584 set smime-encrypt-USER@HOST=FILENAME \e
10585 smime-cipher-USER@HOST=AES256
10589 Additional variables of interest for S/MIME en- and decryption:
10592 .Va smime-encrypt-USER@HOST .
10595 You should carefully consider if you prefer to store encrypted messages
10597 If you do, anybody who has access to your mail folders can read them,
10598 but if you do not, you might be unable to read them yourself later if
10599 you happen to lose your private key.
10602 command saves messages in decrypted form, while the
10606 commands leave them encrypted.
10609 Note that neither S/MIME signing nor encryption applies to message
10610 subjects or other header fields yet.
10611 Thus they may not contain sensitive information for encrypted messages,
10612 and cannot be trusted even if the message content has been verified.
10613 When sending signed messages,
10614 it is recommended to repeat any important header information in the
10618 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
10619 .Ss "Using CRLs with S/MIME or SSL/TLS"
10621 \*(OP Certification authorities (CAs) issue certificate revocation
10622 lists (CRLs) on a regular basis.
10623 These lists contain the serial numbers of certificates that have been
10624 declared invalid after they have been issued.
10625 Such usually happens because the private key for the certificate has
10627 because the owner of the certificate has left the organization that is
10628 mentioned in the certificate, etc.
10629 To seriously use S/MIME or SSL/TLS verification,
10630 an up-to-date CRL is required for each trusted CA.
10631 There is otherwise no method to distinguish between valid and
10632 invalidated certificates.
10633 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
10634 the Internet, so they have to be retrieved by some external mechanism.
10637 \*(UA accepts CRLs in PEM format only;
10638 CRLs in DER format must be converted, like, e.\|g.:
10641 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
10644 To tell \*(UA about the CRLs, a directory that contains all CRL files
10645 (and no other files) must be created.
10650 variables, respectively, must then be set to point to that directory.
10651 After that, \*(UA requires a CRL to be present for each CA that is used
10652 to verify a certificate.
10655 .\" .Ss "Handling spam" {{{
10656 .Ss "Handling spam"
10658 \*(OP \*(UA can make use of several spam interfaces for the purpose of
10659 identification of, and, in general, dealing with spam messages.
10660 A precondition of most commands in order to function is that the
10662 variable is set to one of the supported interfaces.
10663 Once messages have been identified as spam their (volatile)
10665 state can be prompted: the
10669 message specifications will address respective messages and their
10671 entries will be used when displaying the
10673 in the header display.
10678 rates the given messages and sets their
10681 If the spam interface offers spam scores those can also be displayed in
10682 the header display by including the
10692 will interact with the Bayesian filter of the chosen interface and learn
10693 the given messages as
10697 respectively; the last command can be used to cause
10699 of messages; it adheres to their current
10701 state and thus reverts previous teachings.
10706 will simply set and clear, respectively, the mentioned volatile
10708 message flag, without any interface interaction.
10717 requires a running instance of the
10719 server in order to function, started with the option
10721 shall Bayesian filter learning be possible.
10723 .Bd -literal -offset indent
10724 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
10725 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
10726 --daemonize [--local] [--allow-tell]
10730 Thereafter \*(UA can make use of these interfaces:
10732 .Bd -literal -offset indent
10733 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
10734 -Sspamc-command=/usr/local/bin/spamc \e
10735 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
10737 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
10738 -Sspamc-command=/usr/local/bin/spamc \e
10739 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
10743 Using the generic filter approach allows usage of programs like
10745 Here is an example, requiring it to be accessible via
10748 .Bd -literal -offset indent
10749 $ \*(uA -Sspam-interface=filter -Sspam-maxsize=500000 \e
10750 -Sspamfilter-ham="bogofilter -n" \e
10751 -Sspamfilter-noham="bogofilter -N" \e
10752 -Sspamfilter-nospam="bogofilter -S" \e
10753 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
10754 -Sspamfilter-spam="bogofilter -s" \e
10755 -Sspamfilter-rate-scanscore="1;^(.+)$"
10759 Because messages must exist on local storage in order to be scored (or
10760 used for Bayesian filter training), it is possibly a good idea to
10761 perform the local spam check last:
10763 .Bd -literal -offset indent
10764 define spamdelhook {
10766 spamset (header x-dcc-brand-metrics "bulk")
10767 # Server-side spamassassin(1)
10768 spamset (header x-spam-flag "YES")
10769 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
10770 move :S +maybe-spam
10773 move :S +maybe-spam
10775 set folder-hook-FOLDER=spamdelhook
10779 See also the documentation for the variables
10780 .Va spam-interface , spam-maxsize ,
10781 .Va spamc-command , spamc-arguments , spamc-user ,
10782 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
10785 .Va spamfilter-rate-scanscore .
10793 In general it is a good idea to turn on
10799 twice) if something does not work well.
10800 Very often a diagnostic message can be produced that leads to the
10801 problems' solution.
10803 .\" .Ss "\*(UA shortly hangs on startup" {{{
10804 .Ss "\*(UA shortly hangs on startup"
10806 This can have two reasons, one is the necessity to wait for a file lock
10807 and cannot be helped, the other being that \*(UA calls the function
10809 in order to query the nodename of the box (sometimes the real one is
10810 needed instead of the one represented by the internal variable
10812 One may have varying success by ensuring that the real hostname and
10816 or, more generally, that the name service is properly setup \(en
10819 return the expected value?
10820 Does this local hostname has a domain suffix?
10821 RFC 6762 standardized the link-local top-level domain
10823 try again after adding an (additional) entry with this extension.
10826 .\" .Ss "\*(UA exits quick, and output is cleared away" {{{
10827 .Ss "\*(UA exits quick, and output is cleared away"
10829 When this happens even with
10831 set, then this most likely indicates a problem with the creation of
10832 so-called dotlock files: setting
10833 .Va dotlock-ignore-error
10834 should overcome this situation.
10835 This only avoids symptoms, it does not address the problem, though.
10836 Since the output is cleared away \*(UA has support for
10837 .Sx "On terminal control and line editor" ,
10838 and switches to the
10840 which causes the output clearance: by doing
10841 .Ql set termcap='smcup='
10842 this mode can be suppressed, and by setting
10844 (twice) the actual problem should be reported.
10847 .\" .Ss "I cannot login to Google mail aka GMail" {{{
10848 .Ss "I cannot login to Google mail aka GMail"
10850 Since 2014 some free service providers classify programs as
10852 unless they use a special authentification method (OAuth 2.0) which
10853 was not standardized for non-HTTP protocol authentication token query
10854 until August 2015 (RFC 7628).
10857 Different to Kerberos / GSSAPI, which is developed since the mid of the
10858 1980s, where a user can easily create a local authentication ticket for
10859 her- and himself with the locally installed
10861 program, that protocol has no such local part but instead requires
10862 a world-wide-web query to create or fetch a token; since there is no
10863 local cache this query would have to be performed whenever \*(UA is
10864 invoked (in interactive sessions situation may differ).
10867 \*(UA does not support OAuth.
10868 Because of this it is necessary to declare \*(UA a
10869 .Dq less secure app
10870 (on the providers account web page) in order to read and send mail.
10871 However, it also seems possible to take the following steps instead:
10876 give the provider the number of a mobile phone,
10879 .Dq 2-Step Verification ,
10881 create an application specific password (16 characters), and
10883 use that special password instead of the real Google account password in
10884 \*(UA (for more on that see the section
10885 .Sx "On URL syntax and credential lookup" ) .
10889 .\" .Ss "Not \(dqdefunctional\(dq, but the editor key does not work" {{{
10890 .Ss "Not \(dqdefunctional\(dq, but the editor key does not work"
10892 It can happen that the terminal library (see
10893 .Sx "On terminal control and line editor",
10896 reports different codes than the terminal really sends, in which case
10897 \*(UA will tell that a key binding is functional, but will not be able to
10898 recognize it because the received data does not match anything expected.
10903 ings will show the byte sequences that are expected.
10906 To overcome the situation, use, e.g., the program
10908 in conjunction with the
10910 flag if available, to see the byte sequences which are actually produced
10911 by keypresses, and use the variable
10913 to make \*(UA aware of them.
10914 E.g., the terminal this is typed on produces some false sequences, here
10915 an example showing the shifted home key:
10917 .Bd -literal -offset indent
10920 # 1B 5B=[ 31=1 3B=; 32=2 48=H
10925 ? \*(uA -v -Stermcap='kHOM=\eE[H'
10934 .\" .Sh "SEE ALSO" {{{
10944 .Xr spamassassin 1 ,
10953 .Xr mailwrapper 8 ,
10958 .\" .Sh HISTORY {{{
10961 M. Douglas McIlroy writes in his article
10962 .Dq A Research UNIX Reader: Annotated Excerpts \
10963 from the Programmer's Manual, 1971-1986
10966 command already appeared in First Edition
10970 .Bd -ragged -offset indent
10971 Electronic mail was there from the start.
10972 Never satisfied with its exact behavior, everybody touched it at one
10973 time or another: to assure the safety of simultaneous access, to improve
10974 privacy, to survive crashes, to exploit uucp, to screen out foreign
10975 freeloaders, or whatever.
10976 Not until v7 did the interface change (Thompson).
10977 Later, as mail became global in its reach, Dave Presotto took charge and
10978 brought order to communications with a grab-bag of external networks
10984 Mail was written in 1978 by Kurt Shoens and developed as part of the
10987 distribution until 1995.
10988 Mail has then seen further development in open source
10990 variants, noticeably by Christos Zoulas in
10992 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
10993 Ritter in the years 2000 until 2008.
10994 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
10995 This man page is derived from
10996 .Dq The Mail Reference Manual
10997 that was originally written by Kurt Shoens.
11003 .An "Kurt Shoens" ,
11004 .An "Edward Wang" ,
11005 .An "Keith Bostic" ,
11006 .An "Christos Zoulas" ,
11007 .An "Gunnar Ritter" ,
11008 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
11010 .Mt s-mailx@sdaoden.eu ) .
11013 .\" .Sh CAVEATS {{{
11016 \*(ID Interrupting an operation via
11020 is often problematic: many library functions cannot deal with the
11022 that this software (still) performs.
11025 The SMTP and POP3 protocol support of \*(UA is very basic.
11026 Also, if it fails to contact its upstream SMTP server, it will not make
11027 further attempts to transfer the message at a later time (setting
11032 If this is a concern, it might be better to set up a local SMTP server
11033 that is capable of message queuing.
11039 After deleting some message of a POP3 mailbox the header summary falsely
11040 claims that there are no messages to display, one needs to perform
11041 a scroll or dot movement to restore proper state.
11043 In threaded display a power user may encounter crashes very
11044 occasionally (this is may and very).
11048 in the source repository lists future directions.