1 .\"@ nail.1 - S-nail(1) reference manual.
3 .\" Copyright (c) 1980, 1990, 1993
4 .\" The Regents of the University of California. All rights reserved.
6 .\" Gunnar Ritter. All rights reserved.
7 .\" Copyright (c) 2012 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
12 .\" 1. Redistributions of source code must retain the above copyright
13 .\" notice, this list of conditions and the following disclaimer.
14 .\" 2. Redistributions in binary form must reproduce the above copyright
15 .\" notice, this list of conditions and the following disclaimer in the
16 .\" documentation and/or other materials provided with the distribution.
17 .\" 3. All advertising materials mentioning features or use of this software
18 .\" must display the following acknowledgement:
19 .\" This product includes software developed by the University of
20 .\" California, Berkeley and its contributors.
21 .\" This product includes software developed by Gunnar Ritter
22 .\" and his contributors.
24 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS 'AS IS' AND
25 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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33 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 .\" S-nail(1): v14.8.10 / 2016-08-20
49 .\" If not ~/.mailrc, it breaks POSIX compatibility. And adjust main.c.
54 .ds OU [no v15-compat]
55 .ds ID [v15 behaviour may differ]
66 .Nd send and receive Internet mail
79 .Op Fl a Ar attachment
82 .Op Fl q Ar quote-file
84 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
89 .Op Fl Fl \~ Ns Ar mta-option ...
98 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
101 .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 variable 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 A partial set of compatibility options exist, tagged as \*(IN and \*(OU,
128 yet complete compatibility won't be possible.
129 To choose upward compatible behaviour, please set the internal variable
131 Anything which will vanish in v15.0 is tagged \*(OB, and using
133 will print warnings for many use cases of obsolete features.
137 \*(UA is a mail processing system with a command syntax reminiscent of
139 with lines replaced by messages.
140 It is intended to provide the functionality of the POSIX
142 command, but is MIME capable and optionally offers extensions for
143 line editing, S/MIME, SMTP and POP3 among others.
144 It is usable as a mail batch language.
146 .\" .Ss "Options" {{{
149 .Bl -tag -width ".Fl _ Ar _ccount"
152 Explicitly control which of the
154 shall be loaded: if the letter
156 is (case-insensitively) part of the
160 is loaded, likewise the letter
162 controls loading of the user's personal
164 file, whereas the letters
168 explicitly forbid loading of any resource files.
169 This option should be used by scripts: to avoid environmental noise they
172 from any configuration files and create a script-local environment,
173 explicitly setting any desired variable via
175 This option overrides
182 command (see below) for
184 after the startup files have been read.
188 Attach the given file to the message.
189 The same filename conventions as described in the section
191 apply: shell word expansion is restricted to the tilde
196 not be accessible but contain a
198 character, then anything after the
200 is assumed to specify the input character set and anything before
202 the filename: this is the only option to specify the input character set
203 (and don't perform any character set conversion) for text attachments
204 from the command line, not using the
206 tilde escape command.
210 Make standard input and standard output line-buffered.
214 Send a blind carbon copy to
216 Can be used multiple times, but it is also possible to give
217 a comma-separated list of receivers in a single argument, proper shell
218 quoting provided, e.g.,
219 .Ql -b """qrec1 , rec2,rec3, Ex <am@ple>""" .
221 .Sx "On sending mail, and non-interactive mode" .
225 Send carbon copies to the given receiver(s).
226 Can be used multiple times.
232 variable which enables debug messages and disables message delivery,
233 among others; effectively turns almost any operation into a dry-run.
239 variable and thus discard messages with an empty message part body.
240 This is useful for sending messages from scripts.
244 Just check if mail is present (in the specified or system mailbox).
245 If yes, return an exit status of zero, a non-zero value otherwise.
246 To restrict the set of mails to consider in this evaluation a message
247 specification can be added with the option
252 Save the message to send in a file named after the local part of the
253 first recipient's address (instead of in
258 Read in the contents of the user's
260 (or the specified file) for processing;
261 when \*(UA is quit, it writes undeleted messages back to this file
265 Some special conventions are recognized for the string
267 which are documented for the
272 is not a direct argument to the flag
274 but is instead taken from the command line after option processing has
278 that starts with a hyphen, prefix it with a (relative) path, as in
279 .Ql ./-hyphenbox.mbox .
283 Display a summary of the
285 of all messages in the specified or system mailbox and exit.
286 A configurable summary view is available via the
292 Show a short usage summary.
293 Because of widespread use a
295 argument will have the same effect.
301 variable to ignore tty interrupt signals.
304 .It Fl L Ar spec-list
305 Display a summary of all
307 of only those messages in the specified or system mailbox that match the
312 .Sx "Specifying messages"
319 option has been given in addition no header summary is produced,
320 but \*(UA will instead indicate via its exit status wether
326 note that any verbose output is suppressed in this mode and must instead
327 be enabled explicitly (e.g., by using the option
334 variable and thus inhibit initial display of message headers when
335 reading mail or editing a mail folder.
339 Standard flag that inhibits reading the system wide
344 allows more control over the startup sequence; also see
345 .Sx "Resource files" .
349 Initialize the message body with the contents of the specified file,
350 which may be standard input
352 only in non-interactive context.
353 May be given in send mode only.
357 Any folder opened will be in read-only mode.
363 is a valid address then it specifies the envelope sender address to be
366 when a message is send.
369 include a user name, comments etc., then the components will be
370 separated and the name part will be passed to the MTA individually via
374 will also be assigned to the
376 variable, just as if additionally
378 had been specified (therefore affecting SMTP data transfer, too).
380 If instead an empty string is passed as
382 then the content of the variable
384 will be evaluated and used for this purpose whenever the MTA is
386 Note that \*(UA by default, without
388 that is, neither passes
392 flags to the MTA by itself.
395 .It Fl S Ar variable Ns Op = Ns value
396 Sets the internal option
398 and, in case of a value option, assigns
401 Even though variables set via
403 may be overwritten from within resource files,
404 the command line setting will be reestablished after all resource files
409 Specify the subject of the to-be-sent message.
413 The message given (on standard input) is expected to contain, separated
414 from the message body with an empty line, a message header with
419 fields giving its recipients, which will be added to those given on the
421 If a message subject is specified via
423 then it'll be used in favour of one given on the command line.
432 Note you can also specify
436 and the envelope address possibly specified with the option
439 The following, which are normally created automatically based
440 upon the message context, can also be specified:
445 .Ql Mail-Followup-To:
446 (special address massage will however still occur for the latter).
447 In fact custom header fields may also be used, the content of which
448 is passed through unchanged.
452 can be embedded, too.
456 Read the system mailbox of
458 (appropriate privileges presumed), and
461 in some aspects, e.g. in respect to
470 Show \*(UA's version and exit.
476 option enables display of some informational context messages.
477 Using it twice increases the level of verbosity.
483 to the list of commands to be executed before normal operation starts.
487 .Va batch-exit-on-error ;
488 the only possibility to execute commands in non-interactive mode when
489 reading startup files is actively prohibited.
495 even if not in interactive mode.
500 In batch mode the full set of commands is available, just like in
501 interactive mode, and diverse variable settings and internal states are
502 adjusted for batch necessities, e.g., it sets
513 It also enables processing of
514 .Sx "TILDE ESCAPES" .
515 E.g., the following should send an email message to
517 .Bd -literal -offset indent
518 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en~.\enx\en' | \e
519 LC_ALL=C \*(ua -:/ -d#
524 This flag forces termination of option processing in order to prevent
527 It also forcefully puts \*(UA into send mode, see
528 .Sx "On sending mail, and non-interactive mode" .
532 In the above list of supported command line options,
536 are implemented by means of setting the respective option, as via
539 .Op Ar mta-option ...
541 arguments that are given at the end of the command line after a
543 separator will be passed through to the mail-transfer-agent (MTA) and
544 persist for an entire (interactive) session \(en if the setting of
546 allows their recognition;
547 MTA arguments can also be specified in the variable
548 .Va sendmail-arguments ;
549 find MTA interaction described in more detail in the documentation of
551 MTA arguments are ignored when mail is send via SMTP data transfer.
554 .\" .Ss "A starter" {{{
557 \*(UA is a direct descendant of
559 Mail, a successor of the Research
562 .Dq was there from the start
567 Mail reference manual begins with the following words:
569 .Bd -ragged -offset indent
570 Mail provides a simple and friendly environment for sending and
572 It divides incoming mail into its constituent messages and allows the
573 user to deal with them in any order.
574 In addition, it provides a set of
576 -like commands for manipulating messages and sending mail.
577 Mail offers the user simple editing capabilities to ease the composition
578 of outgoing messages, as well as providing the ability to define and
579 send to names which address groups of users.
583 \*(UA is thus the user side of the
585 mail system, whereas the system side (mail-transfer-agent, MTA) was
586 traditionally taken by
592 are often used for this purpose instead.
593 If the \*(OPal SMTP is included in the
595 of \*(UA then the system side is not a mandatory precondition for mail
599 Because \*(UA strives for compliance with POSIX
601 it is likely that some configuration settings have to be adjusted before
602 using it is a smooth experience.
605 file already bends those standard settings a bit towards more user
606 friendliness and safety, e.g., it sets the
610 variables in order to suppress the automatic moving of messages to
612 that would otherwise occur (see
613 .Sx "Message states" )
616 to not remove empty files in order not to mangle file permissions when
617 files eventually get recreated.
620 option so that by default file grouping (via the
622 prefix as documented also for
627 contains some further suggestions.
630 .\" .Ss "On sending mail, and non-interactive mode" {{{
631 .Ss "On sending mail, and non-interactive mode"
633 To send a message to one or more people, using a local
634 mail-transfer-agent (MTA; the executable path can be set via
636 or the \*(OPal builtin SMTP (set and see the variable
638 transport to actually deliver the generated mail message, \*(UA can be
639 invoked with arguments which are the names of people to whom the mail
642 .Bd -literal -offset indent
643 $ \*(ua -s Subject -a attachm.ent bill@host1 'Bob <bob@host2>'
644 # But... try it in an isolated dry-run mode first
645 $ LC_ALL=C \*(ua -:/ -d -vv -Sfrom="me <he@exam.ple>" \e
646 -b bcc@exam.ple -c cc@exam.ple \e
647 -s Subject -. "(Lovely) Bob <bob@host2>"
651 The command line options
655 can be used to add (blind) carbon copy receivers.
656 Almost always lists of addresses can be given where an address is
658 whereas comma-separated lists should be given, e.g.,
659 .Ql -c """r1@exam.ple , r2@exam.ple,r3@exam.ple""" ,
660 that very example could also be given as the whitespace-separated list
661 .Ql -c """r1@exam.ple r2@exam.ple r3@exam.ple""" ,
662 but which for obvious reasons would not work for
663 .Ql -c """R1 <r1@exam.ple>, R2 (heh!) <r2@exam.ple>""" .
666 The user is then expected to type in the message contents.
667 In this compose mode \*(UA treats lines beginning with the character
669 special \(en these are so-called
671 which can be used to read in files, process shell commands, add and edit
672 attachments and more; e.g., the tilde escape
674 will start the text editor to revise the message in it's current state,
676 allows editing of the message recipients and
678 gives an overview of available tilde escapes.
682 at the beginning of an empty line leaves compose mode and causes the
683 message to be sent, whereas typing
686 twice will abort the current letter (saving its contents in the file
694 A number of variables can be used to alter default behavior; e.g.,
699 will automatically startup a text editor when compose mode is entered,
701 will cause the user to be prompted actively for carbon-copy recipients
704 option will allow leaving compose mode by writing a line consisting
709 Very important, though, is to define which
711 may be used when sending messages, usually by setting the option
714 having read the section
715 .Sx "The mime.types files"
716 to understand how the MIME-type of outgoing attachments is classified
717 and the knowledge that messages are sent asynchronously unless
719 is set: only with it MTA delivery errors will be recognizable.
724 is often necessary (e.g., in conjunction with
726 or desirable, you may want to do some dry-run tests before you go.
727 Saving a copy of the sent messages in a
729 may also be desirable \(en as for most mailbox file targets some
730 special conventions are recognized, see the
732 command for more on that.
734 .Sx "On URL syntax and credential lookup"
735 will spread some light on the
737 variable chains as well as on using URLs for accessing protocol-specific
742 contains an example configuration for sending messages via some of the
743 well-known public mail providers;
744 note it also gives a compact overview on how to setup a secure SSL/TLS
748 Message recipients (as specified on the command line or defined in
753 may not only be email addressees but can also be names of mailboxes and
754 even complete shell command pipe specifications.
755 Proper (shell) quoting is necessary, e.g., to embed whitespace characters.
756 (Recall that \*(UA deals with mail standards, therefore those define the
757 rules with which content is interpreted.)
760 is not set then only network addresses (see
762 for a description of mail addresses) and plain user names (including MTA
763 aliases) may be used, other types will be filtered out, giving a warning
766 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
767 .\" grep the latter for the complete picture
771 is set then extended recipient addresses will optionally be accepted:
772 Any name which starts with a vertical bar
774 character specifies a command pipe \(en the command string following the
776 is executed and the message is sent to its standard input;
777 Likewise, any name that starts with the character slash
779 or the character sequence dot slash
781 is treated as a file, regardless of the remaining content.
782 Any other name which contains an at sign
784 character is treated as a network address;
785 Any other name which starts with a plus sign
787 character specifies a mailbox name;
788 Any other name which contains a slash
790 character but no exclamation mark
794 character before also specifies a mailbox name;
795 What remains is treated as a network address.
797 .Bd -literal -offset indent
798 $ echo bla | \*(ua -Sexpandaddr -s test ./mbox.mbox
799 $ echo bla | \*(ua -Sexpandaddr -s test '|cat >> ./mbox.mbox'
800 $ echo safe | LC_ALL=C \e
801 \*(ua -:/ -Sv15-compat -Ssendwait -Snosave \e
802 -Sexpandaddr=fail,-all,+addr -s test \e
807 It is possible to create personal distribution lists via the
809 command, so that, for instance, the user can send mail to
811 and have it go to a group of people:
814 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
817 Please note that this mechanism has nothing in common with the system
818 wide aliases that may be used by the local MTA (mail-transfer-agent),
819 which are subject to the
823 and are often tracked in a file
829 Personal aliases will be expanded by \*(UA before the message is sent,
830 and are thus a convenient alternative to specifying each addressee by
834 To avoid environmental noise scripts should
836 \*(UA from any configuration files and create a script-local
837 environment, ideally with the command line options
839 to disable any configuration file in conjunction with repititions of
841 to specify variables:
843 .Bd -literal -offset indent
844 $ env LC_ALL=C password=NOTSECRET \e
845 \*(ua -:/ -Sv15-compat -Ssendwait -Snosave \e
846 -Sexpandaddr=fail,-all,+addr \e
847 -S 'smtp=smtps://mylogin@some.host:465' -Ssmtp-auth=login \e
848 -S 'from=scriptreply@domain' \e
849 -s 'subject' -a attachment_file \e
850 -. "Recipient 1 <recipient1@domain>" recipient2@domain \e
855 In interactive mode, which is introduced in the next section, messages
856 can be sent by calling the
858 command with a list of recipient addresses \(em the semantics are
859 completely identical to non-interactive message sending, except that
860 it is likely necessary to separate recipient lists with commas:
862 .Bd -literal -offset indent
863 $ \*(ua -d -Squiet -Semptystart
864 "/var/spool/mail/user": 0 messages
865 ? mail "Recipient 1 <recipient1@domain>", recipient2@domain
866 ? # Will do the right thing (tm)
867 ? m recipient1@domain recipient2@domain
871 .\" .Ss "On reading mail, and interactive mode" {{{
872 .Ss "On reading mail, and interactive mode"
874 When invoked without addressees \*(UA enters interactive mode in which
876 When used like that the user's system mailbox (see the command
878 for an in-depth description of the different mailbox types that exist)
879 is read in and a one line header of each message therein is displayed.
880 The visual style of this summary of
882 can be adjusted through the variable
884 and the possible sorting criterion via
886 If the initially opened mailbox is empty \*(UA will instead exit
887 immediately (after displaying a message) unless the variable
896 will give a listing of all available commands and
898 will give a summary of some common ones.
899 If the \*(OPal documentation strings are available one can type
901 and see the actual expansion of
903 and what it's purpose is, i.e., commands can be abbreviated
904 (note that POSIX defines some abbreviations, so that the alphabetical
905 order of commands doesn't necessarily relate to the abbreviations; it is
906 possible to define overwrites with the
911 Messages are given numbers (starting at 1) which uniquely identify
912 messages; the current message \(en the
914 \(en will either be the first new message, or the first unread message,
915 or the first message of the mailbox; the option
917 will instead cause usage of the last message for this purpose.
922 ful of header summaries containing the
926 will display only the summaries of the given messages, defaulting to the
930 Messages can be displayed on the user's terminal with the
934 By default the current message
936 is displayed, but like with many other commands it is possible to give
937 a fancy message specification (see
938 .Sx "Specifying messages" ) ,
941 will display all unread messages,
946 will type the messages 1 and 5,
948 will type the messages 1 through 5, and
952 will display the last and the next message, respectively.
955 (a more substantial alias of the standard command
957 will display a header summary of the given message specification list
958 instead of their content, e.g., the following will search for subjects:
961 .Dl ? from """@Some subject to search for"""
964 In the default setup all header fields of a message will be displayed,
965 but this can be changed: either by blacklisting a list of fields via
967 or by whitelisting only a given list with the
970 .Ql Ic \:retain Ns \0date from to cc subject .
971 In order to display all header fields of a message regardless of
972 currently active ignore or retain lists, use the command
976 controls wether and when \*(UA will use the configured
978 for display instead of directly writing to the user terminal
979 (generally speaking).
980 Note that historically the global
982 not only adjusts the list of displayed headers, but also sets
986 Dependent upon the configuration a line editor (see the section
987 .Sx "On terminal control and line editor" )
988 aims at making user experience with the many
991 When reading the system mailbox or when
995 specified a mailbox explicitly prefixed with the special
997 modifier (propagating the mailbox to a primary one) then messages which
998 have been read will be moved to a secondary mailbox, the user's
1000 file, automatically when the mailbox is left, either by changing the
1001 active mailbox or by quitting \*(UA (also see
1002 .Sx "Message states" )
1003 \(en this automatic moving from a system or primary to the secondary
1004 mailbox is not performed when the variable
1009 After examining a message the user can also
1013 to the sender and all recipients or
1015 exclusively to the sender(s).
1016 Messages can also be
1018 ed (shorter alias is
1020 Note that when replying to or forwarding a message recipient addresses
1021 will be stripped from comments and names unless the option
1024 Deletion causes \*(UA to forget about the message;
1025 This is not irreversible, though, one can
1027 the message by giving its number,
1028 or the \*(UA session can be ended by giving the
1033 To end a mail processing session one may either issue
1035 to cause a full program exit, which possibly includes
1036 automatic moving of read messages to
1038 as well as updating the \*(OPal line editor
1042 instead in order to prevent any of these actions.
1045 .\" .Ss "HTML mail and MIME attachments" {{{
1046 .Ss "HTML mail and MIME attachments"
1048 Messages which are HTML-only get more and more common and of course many
1049 messages come bundled with a bouquet of MIME attachments.
1050 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1051 with HTML messages (see
1052 .Sx "The mime.types files" ) ,
1053 it normally can't deal with any of these itself, but instead programs
1054 need to become registered to deal with specific MIME types or file
1056 These programs may either prepare plain text versions of their input
1057 in order to enable \*(UA to display the content on the terminal,
1058 or display the content themselves, for example in a graphical window.
1061 To install an external handler program for a specific MIME type set an
1063 .Va pipe-TYPE/SUBTYPE
1064 variable; to instead define a handler for a specific file extension set
1067 variable \(en these handlers take precedence.
1068 \*(OPally \*(UA supports mail user agent configuration as defined in
1069 RFC 1524; this mechanism, documented in the section
1070 .Sx "The Mailcap files" ,
1071 will be queried for display or quote handlers if none of the former two
1072 .\" TODO v15-compat "will be" -> "is"
1073 did; it will be the sole source for handlers of other purpose.
1074 A last source for handlers may be the MIME type definition itself, if
1075 the \*(UA specific type-marker extension was used when defining the type
1078 (Many of the builtin MIME types do so by default.)
1082 .Va mime-counter-evidence
1083 can be set to improve dealing with faulty MIME part declarations as are
1084 often seen in real-life messages.
1085 E.g., to display a HTML message inline (that is, converted to a more
1086 fancy plain text representation than the builtin converter is capable to
1087 produce) with either of the text-mode browsers
1091 teach \*(UA about MathML documents and make it display them as plain
1092 text, and to open PDF attachments in an external PDF viewer,
1093 asynchronously and with some other magic attached:
1095 .Bd -literal -offset indent
1096 if $features !@ HTML-FILTER
1097 #set pipe-text/html="elinks -force-html -dump 1"
1098 set pipe-text/html="lynx -stdin -dump -force_html"
1099 # Display HTML as plain text instead
1100 #set pipe-text/html=@
1102 mimetype '@ application/mathml+xml mathml'
1103 set pipe-application/pdf="@&=@ \e
1104 trap \e"rm -f \e\e\e"${NAIL_FILENAME_TEMPORARY}\e\e\e"\e" EXIT;\e
1105 trap \e"trap \e\e\e"\e\e\e" INT QUIT TERM; exit 1\e" \e INT QUIT TERM;\e
1106 xpdf \e"${NAIL_FILENAME_TEMPORARY}\e""
1110 Note: special care must be taken when using such commands as mail
1111 viruses may be distributed by this method: if messages of type
1112 .Ql application/x-sh
1113 or files with the extension
1115 were blindly filtered through the shell, for example, a message sender
1116 could easily execute arbitrary code on the system \*(UA is running on.
1117 For more on MIME, also in respect to sending of messages, see the
1119 .Sx "The mime.types files" ,
1120 .Sx "The Mailcap files"
1125 .\" .Ss "Mailing lists" {{{
1128 \*(UA offers some support to ease handling of mailing lists.
1131 promotes all given arguments to known mailing lists, and
1133 sets their subscription attribute, creating them first as necessary.
1138 automatically, but only resets the subscription attribute.)
1139 Using the commands without arguments will show (a subset of) all
1140 currently defined mailing lists.
1145 can be used to mark out messages with configured list addresses
1146 in the header display.
1149 \*(OPally mailing lists may also be specified as (extended) regular
1150 expressions, which allows matching of many addresses with a single
1152 However, all fully qualified list addresses are matched via a fast
1153 dictionary, whereas expressions are placed in (a) list(s) which is
1154 (are) matched sequentially.
1156 .Bd -literal -offset indent
1157 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1158 mlist a1@b1.c1 a2@b2.c2 .*@lists.c3$
1159 mlsubscribe a4@b4.c4 exact@lists.c3
1164 .Va followup-to-honour
1166 .Ql Mail-\:Followup-\:To:
1167 header is honoured when the message is being replied to (via
1173 controls wether this header is created when sending mails; it will be
1174 created automatically for a couple of reasons, too, like when the
1176 .Dq mailing list specific
1181 is used to respond to a message with its
1182 .Ql Mail-Followup-To:
1186 A difference in between the handling of known and subscribed lists is
1187 that the address of the sender is usually not part of a generated
1188 .Ql Mail-Followup-To:
1189 when addressing the latter, whereas it is for the former kind of lists.
1190 Usually because there are exceptions: say, if multiple lists are
1191 addressed and not all of them are subscribed lists.
1193 For convenience \*(UA will, temporarily, automatically add a list
1194 address that is presented in the
1196 header of a message that is being responded to to the list of known
1198 Shall that header have existed \*(UA will instead, dependend on the
1200 .Va reply-to-honour ,
1203 for this purpose in order to accept a list administrators' wish that
1204 is supposed to have been manifested like that (but only if it provides
1205 a single address which resides on the same domain as what is stated in
1209 .\" .Ss "Resource files" {{{
1210 .Ss "Resource files"
1212 Upon startup \*(UA reads in several resource files:
1214 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1217 System wide initialization file.
1218 Reading of this file can be suppressed, either by using the
1222 command line options, or by setting the environment variable
1223 .Ev NAIL_NO_SYSTEM_RC .
1227 File giving initial commands.
1228 A different file can be chosen by setting the environment variable
1230 Reading of this file can be suppressed with the
1232 command line option.
1234 .It Va NAIL_EXTRA_RC
1235 Can be used to define an optional startup file to be read after all
1236 other resource files.
1237 It can be used to specify settings that are not understood by other
1239 implementations, for example.
1240 This variable is only honoured when defined in a resource file.
1244 The content of these files is interpreted as follows:
1247 .Bl -bullet -compact
1249 A lines' leading whitespace is removed.
1251 Empty lines are ignored.
1253 Any other line is interpreted as a command.
1254 It may be spread over multiple input lines if the newline character is
1256 by placing a backslash character
1258 as the last character of the line; whereas any leading whitespace of
1259 follow lines is ignored, trailing whitespace before a escaped newline
1260 remains in the input.
1262 If the line (content) starts with the number sign
1264 then it is a comment-command \(en a real command! \(en and also ignored.
1265 This command is the only form of comment that is understood.
1271 .Bd -literal -offset indent
1272 # This line is a comment command. And y\e
1273 es, it is really continued here.
1280 .\" .Ss "Character sets" {{{
1281 .Ss "Character sets"
1283 \*(OP \*(UA detects the character set of the terminal by using
1284 mechanisms that are controlled by the
1289 should give an overview); the \*(UA internal variable
1291 will be set to the detected terminal character set accordingly
1292 and will thus show up in the output of the commands
1298 However, a user supplied
1300 value is not overwritten by this detection mechanism: this
1302 must be used if the detection doesn't work properly,
1303 and it may be used to adjust the name of the locale character set.
1304 E.g., on BSD systems one may use a locale with the character set
1305 ISO8859-1, which is not a valid name for this character set; to be on
1306 the safe side, one may set
1308 to the correct name, which is ISO-8859-1.
1311 Note that changing the value doesn't mean much beside that,
1312 since several aspects of the real character set are implied by the
1313 locale environment of the system,
1314 and that stays unaffected by the content of an overwritten
1317 (This is mostly an issue when interactively using \*(UA, though.
1318 It is actually possible to send mail in a completely
1320 locale environment, an option that \*(UA's test-suite uses excessively.)
1323 If no character set conversion capabilities have been compiled into
1326 doesn't include the term
1330 will be the only supported character set,
1331 it is simply assumed that it can be used to exchange 8-bit messages,
1332 and the rest of this section does not apply;
1333 it may however still be necessary to explicitly set it if automatic
1334 detection fails, since in that case it defaults to the mentioned
1335 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1339 When reading messages, their text is converted into
1341 as necessary in order to display them on the users terminal.
1342 Unprintable characters and invalid byte sequences are detected
1343 and replaced by proper substitution characters (unless the variable
1345 was set once \*(UA was started).
1347 .Va charset-unknown-8bit
1348 to deal with another hairy aspect of message interpretation.
1351 When sending messages all their parts and attachments are classified.
1352 Whereas no character set conversion is performed on those parts which
1353 appear to be binary data,
1354 the character set being used must be declared within the MIME header of
1355 an outgoing text part if it contains characters that do not conform to
1356 the set of characters that are allowed by the email standards.
1357 Permissible values for character sets can be declared using the
1361 which defines a catch-all last-resort fallback character set that is
1362 implicitly appended to the list of character-sets in
1366 When replying to a message and the variable
1367 .Va reply-in-same-charset
1368 is set then the character set of the message being replied to is tried
1370 And it is also possible to make \*(UA work even more closely related to
1371 the current locale setting automatically by using the variable
1372 .Va sendcharsets-else-ttycharset ,
1373 please see there for more information.
1376 All the specified character sets are tried in order unless the
1377 conversion of the part or attachment succeeds.
1378 If none of the tried (8-bit) character sets is capable to represent the
1379 content of the part or attachment,
1380 then the message will not be sent and its text will optionally be
1384 In general, if the message
1385 .Dq Cannot convert from a to b
1386 appears, either some characters are not appropriate for the currently
1387 selected (terminal) character set,
1388 or the needed conversion is not supported by the system.
1389 In the first case, it is necessary to set an appropriate
1391 locale and/or the variable
1395 The best results are usually achieved when \*(UA is run in a UTF-8
1396 locale on a UTF-8 capable terminal, in which case the full Unicode
1397 spectrum of characters is available.
1398 In this setup characters from various countries can be displayed,
1399 while it is still possible to use more simple character sets for sending
1400 to retain maximum compatibility with older mail clients.
1403 On the other hand the POSIX standard defines a locale-independent 7-bit
1404 .Dq portable character set
1405 that should be used when overall portability is an issue, the even more
1406 restricted subset named
1407 .Dq portable filename character set
1408 consisting of A-Z, a-z, 0-9, period
1417 .\" .Ss "Message states" {{{
1418 .Ss "Message states"
1420 \*(UA differentiates in between several different message states;
1421 the current state will be reflected in header summary displays if
1423 is configured to do so (via the internal variable
1425 and messages can also be selected and be acted upon depending on their
1427 .Sx "Specifying messages" ) .
1428 When operating on the system mailbox or in primary mailboxes opened with
1433 special actions, like the automatic moving of messages to the secondary
1435 mailbox may be applied when the mailbox is left (also implicitly via
1436 a successful exit of \*(UA, but not if the special command
1438 is used) \(en however, because this may be irritating to users which
1441 mail-user-agents, the default global
1447 variables in order to suppress this behaviour.
1449 .Bl -tag -width ".It Ql _reserved"
1451 Message has neither been viewed nor moved to any other state.
1452 Such messages are retained even in the system mailbox.
1455 Message has neither been viewed nor moved to any other state, but the
1456 message was present already when the mailbox has been opened last:
1457 Such messages are retained even in the system mailbox.
1460 The message has been processed by one of the following commands:
1480 commands may also cause the next message to be marked as read, depending
1486 command is used, messages that are in the system mailbox or in mailboxes
1487 which were opened with the special
1491 state when the mailbox is left will be saved in
1498 The message has been processed by one of the following commands:
1504 can be used to access such messages.
1507 The message has been processed by a
1509 command and it will be retained in its current location.
1512 The message has been processed by one of the following commands:
1518 command is used, messages that are in the system mailbox or in mailboxes
1519 which were opened with the special
1523 state when the mailbox is left will be deleted; they will be saved in
1531 .\" .Ss "Specifying messages" {{{
1532 .Ss "Specifying messages"
1539 can be given a list of message numbers as arguments to apply to a number
1540 of messages at once.
1543 deletes messages 1 and 2,
1546 will delete the messages 1 through 5.
1547 In sorted or threaded mode (see the
1551 will delete the messages that are located between (and including)
1552 messages 1 through 5 in the sorted/threaded order, as shown in the
1555 Multiple colon modifiers can be joined into one, e.g.,
1557 The following special message names exist:
1559 .Bl -tag -width ".It Ar _n_u"
1565 All old messages (any not in state
1590 All answered messages
1595 All messages marked as draft.
1597 \*(OP All messages classified as spam.
1599 \*(OP All messages with unsure spam classification.
1601 The current message, the so-called
1604 The message that was previously the current message.
1606 The parent message of the current message,
1607 that is the message with the Message-ID given in the
1609 field or the last entry of the
1611 field of the current message.
1613 The next previous undeleted message,
1614 or the next previous deleted message for the
1617 In sorted/threaded mode,
1618 the next previous such message in the sorted/threaded order.
1620 The next undeleted message,
1621 or the next deleted message for the
1624 In sorted/threaded mode,
1625 the next such message in the sorted/threaded order.
1627 The first undeleted message,
1628 or the first deleted message for the
1631 In sorted/threaded mode,
1632 the first such message in the sorted/threaded order.
1635 In sorted/threaded mode,
1636 the last message in the sorted/threaded order.
1640 selects the message addressed with
1644 is any other message specification,
1645 and all messages from the thread that begins at it.
1646 Otherwise it is identical to
1651 the thread beginning with the current message is selected.
1656 All messages that were included in the message list for the previous
1659 .It Ar / Ns Ar string
1660 All messages that contain
1662 in the subject field (case ignored).
1669 the string from the previous specification of that type is used again.
1671 .It Xo Op Ar @ Ns Ar name-list Ns
1674 All messages that contain the given case-insensitive search
1676 ession; if the \*(OPal regular expression (see
1678 support is available
1680 will be interpreted as (an extended) one if any of the
1682 (extended) regular expression characters is seen.
1684 .Ar @ Ns Ar name-list
1685 part is missing, the search is restricted to the subject field body,
1688 specifies a comma-separated list of header fields to search, as in
1690 .Dl '@to,from,cc@Someone i ought to know'
1692 In order to search for a string that includes a
1694 (commercial at) character the
1696 is effectively non-optional, but may be given as the empty string.
1697 Some special header fields may be abbreviated:
1711 respectively and case-insensitively.
1716 can be used to search in (all of) the header(s) of the message, and the
1725 can be used to perform full text searches \(en whereas the former
1726 searches only the body, the latter also searches the message header.
1728 This message specification performs full text comparison, but even with
1729 regular expression support it is almost impossible to write a search
1730 expression that savely matches only a specific address domain.
1731 To request that the content of the header is treated as a list of
1732 addresses, and to strip those down to the plain email address which the
1733 search expression is to be matched against, prefix the header name
1734 (abbreviation) with a tilde
1737 .Dl @~f@@a\e.safe\e.domain\e.match$
1741 .Dq any substring matches
1744 header, which will match addresses (too) even if
1746 is set (and POSIX says
1747 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1750 variable is set, only the local part of the address is evaluated
1751 for the comparison, not ignoring case, and the setting of
1753 is completely ignored.
1754 For finer control and match boundaries use the
1756 search expression; the \*(OPal IMAP-style
1758 expression can also be used if substring matches are desired.
1762 \*(OP IMAP-style SEARCH expressions may also be used.
1763 This addressing mode is available with all types of folders;
1764 \*(UA will perform the search locally as necessary.
1765 Strings must be enclosed by double quotes
1767 in their entirety if they contain white space or parentheses;
1768 within the quotes, only backslash
1770 is recognized as an escape character.
1771 All string searches are case-insensitive.
1772 When the description indicates that the
1774 representation of an address field is used,
1775 this means that the search string is checked against both a list
1778 .Bd -literal -offset indent
1779 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1784 and the addresses without real names from the respective header field.
1785 These search expressions can be nested using parentheses, see below for
1789 .Bl -tag -compact -width ".It Ar _n_u"
1790 .It Ar ( criterion )
1791 All messages that satisfy the given
1793 .It Ar ( criterion1 criterion2 ... criterionN )
1794 All messages that satisfy all of the given criteria.
1796 .It Ar ( or criterion1 criterion2 )
1797 All messages that satisfy either
1802 To connect more than two criteria using
1804 specifications have to be nested using additional parentheses,
1806 .Ql (or a (or b c)) ,
1810 .Ql ((a or b) and c) .
1813 operation of independent criteria on the lowest nesting level,
1814 it is possible to achieve similar effects by using three separate
1818 .It Ar ( not criterion )
1819 All messages that do not satisfy
1821 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1822 All messages that contain
1824 in the envelope representation of the
1827 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1828 All messages that contain
1830 in the envelope representation of the
1833 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1834 All messages that contain
1836 in the envelope representation of the
1839 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1840 All messages that contain
1845 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1846 All messages that contain
1848 in the envelope representation of the
1851 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1852 All messages that contain
1857 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1858 All messages that contain
1861 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1862 All messages that contain
1864 in their header or body.
1865 .It Ar ( larger size )
1866 All messages that are larger than
1869 .It Ar ( smaller size )
1870 All messages that are smaller than
1874 .It Ar ( before date )
1875 All messages that were received before
1877 which must be in the form
1881 denotes the day of the month as one or two digits,
1883 is the name of the month \(en one of
1884 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1887 is the year as four digits, e.g.,
1891 All messages that were received on the specified date.
1892 .It Ar ( since date )
1893 All messages that were received since the specified date.
1894 .It Ar ( sentbefore date )
1895 All messages that were sent on the specified date.
1896 .It Ar ( senton date )
1897 All messages that were sent on the specified date.
1898 .It Ar ( sentsince date )
1899 All messages that were sent since the specified date.
1901 The same criterion as for the previous search.
1902 This specification cannot be used as part of another criterion.
1903 If the previous command line contained more than one independent
1904 criterion then the last of those criteria is used.
1908 .\" .Ss "On URL syntax and credential lookup" {{{
1909 .Ss "On URL syntax and credential lookup"
1911 \*(IN For accessing protocol-specific resources usage of Uniform
1912 Resource Locators (URL, RFC 1738) has become omnipresent.
1913 \*(UA expects and understands URLs in the following form;
1916 denote optional parts, optional either because there also exist other
1917 ways to define the information in question or because support of the
1918 part is protocol-specific (e.g.,
1920 is used by the IMAP protocol but not by POP3);
1925 are specified they must be given in URL percent encoded form (RFC 3986;
1933 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1936 Note that these \*(UA URLs most often don't conform to any real
1937 standard, but instead represent a normalized variant of RFC 1738 \(en
1938 they are not used in data exchange but only ment as a compact,
1939 easy-to-use way of defining and representing information in
1940 a well-known notation.
1943 Many internal variables of \*(UA exist in multiple versions, called
1944 variable chains for the rest of this document: the plain
1949 .Ql variable-USER@HOST .
1956 had been specified in the respective URL, otherwise it refers to the plain
1962 that had been found when doing the user chain lookup as is described
1965 will never be in URL percent encoded form, wether it came from an URL or
1966 not; i.e., values of
1967 .Sx "INTERNAL VARIABLES"
1968 must not be URL percent encoded.
1971 For example, wether an hypothetical URL
1972 .Ql smtp://hey%3Ayou@our.house
1973 had been given that includes a user, or wether the URL was
1974 .Ql smtp://our.house
1975 and the user had been found differently, to lookup the variable chain
1976 .Va smtp-use-starttls
1977 \*(UA first looks for wether
1978 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1979 is defined, then wether
1980 .Ql smtp-\:use-\:starttls-\:our.house
1981 exists before finally ending up looking at the plain variable itself.
1984 \*(UA obeys the following logic scheme when dealing with the
1985 necessary credential informations of an account:
1991 has been given in the URL the variables
1995 are looked up; if no such variable(s) can be found then \*(UA will,
1996 when enforced by the \*(OPal variables
1997 .Va netrc-lookup-HOST
2004 specific entry which provides a
2006 name: this lookup will only succeed if unambiguous (one possible matching
2010 If there is still no
2012 then \*(UA will fall back to the user who is supposed to run \*(UA:
2013 either the name that has been given with the
2015 command line option (or, equivalently, but with less precedence, the
2016 environment variable
2021 The identity of this user has been fixated during \*(UA startup and is
2022 known to be a valid user on the current host.
2025 Authentication: unless otherwise noted this will lookup the
2026 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
2027 variable chain, falling back to a protocol-specific default should this
2033 has been given in the URL, then if the
2035 has been found through the \*(OPal
2037 then that may have already provided the password, too.
2038 Otherwise the variable chain
2039 .Va password-USER@HOST , password-HOST , password
2040 is looked up and used if existent.
2042 \*(OP Then if any of the variables of the chain
2043 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2045 is set the shell command specified therein is run and the output (less
2046 newline characters) will be used as the password.
2047 It is perfectly valid for such an agent to simply not return any data,
2048 in which case the password lookup is continued somewhere else;
2049 Any command failure is treated as a hard error, however.
2051 Afterwards the complete \*(OPal variable chain
2052 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2056 cache is searched for a password only (multiple user accounts for
2057 a single machine may exist as well as a fallback entry without user
2058 but with a password).
2060 If at that point there is still no password available, but the
2061 (protocols') chosen authentication type requires a password, then in
2062 interactive mode the user will be prompted on the terminal.
2067 S/MIME verification works relative to the values found in the
2071 header field(s), which means that the values of
2072 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2074 .Va smime-sign-message-digest
2075 will not be looked up using the
2079 chains from above but instead use the corresponding values from the
2080 message that is being worked on.
2081 In unusual cases multiple and different
2085 combinations may therefore be involved \(en on the other hand those
2086 unusual cases become possible.
2087 The usual case is as short as:
2090 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2091 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2096 contains complete example configurations.
2099 .\" .Ss "On terminal control and line editor" {{{
2100 .Ss "On terminal control and line editor"
2102 \*(OP \*(UA can be configured to support a line editor,
2103 history lists that can be saved in between sessions,
2104 and terminal control to improve interactive usage experience.
2105 For the former one may either link against an external library
2106 .Pf ( Xr readline 3 ;
2107 behaviour of \*(UA may differ slightly),
2108 or enable the builtin Mailx-Line-Editor (MLE), which should work in all
2109 environments which comply to the ISO C standard
2111 and which will support wide glyphs if possible (the necessary
2112 functionality had been removed from ISO C, but was included in
2114 Prevent usage of a line editor in interactive mode by setting the
2116 .Va line-editor-disable .
2121 feature is available then input from line editor prompts will be saved
2122 in a history list that can be searched in and be expanded from.
2123 Such saving can be prevented by prefixing input with any amount of
2125 Aspects of history, like allowed content, maximum size etc., can be
2126 configured with the variables
2129 .Va history-gabby-persist
2134 \*(OP For terminal control the standard
2137 will be initialized to work with the
2139 inal in order to enhance or enable interactive usage aspects, for example
2140 .Sx "Coloured display" ,
2141 and extend behaviour of the MLE, which may learn the key-sequences of
2142 special keys like, e.g., the cursor and function keys, and which will
2143 automatically enter the so-called
2145 alternative screen shall the terminal support it.
2146 The internal variable
2148 can be used to overwrite settings or to learn (correct(ed)) keycodes.
2149 Interaction with the
2151 can be disabled completely by setting
2152 .Va termcap-disable ,
2153 which may be necessary for proper operation on the actual terminal;
2154 note that the variable
2156 will be queried by some \*(OPal modules of \*(UA, like the MLE,
2157 regardless of the availability of the mentioned library and wether its
2161 \*(OP The builtin \*(UA line editor MLE supports the following
2162 operations; the notation
2164 stands for the combination of the
2166 key plus the mentioned character, e.g.,
2169 .Dq hold down control key and press the A key .
2170 Especially without termcap support setting respective entries in
2172 will help shall MLE misbehave.
2175 .Bl -tag -compact -width "Ql _M"
2177 Go to the start of the line.
2179 Move the cursor backward one character.
2181 Forward delete the character under the cursor;
2182 quits \*(UA if used on the empty line unless the
2186 Go to the end of the line.
2188 Move the cursor forward one character.
2191 Cancel current operation, full reset.
2192 If there is an active history search or tabulator expansion then this
2193 command will first reset that, reverting to the former line content;
2194 thus a second reset is needed for a full reset in this case.
2195 In all cases \*(UA will reset a possibly used multibyte character input
2201 backward delete one character.
2205 .Dq horizontal tabulator :
2206 try to expand the word before the cursor.
2208 .Dq tabulator-completion
2209 as is known from the
2211 but really means the usual \*(UA expansion, as documented for
2213 yet it involves shell expansion as a last step, too.)
2218 complete this line of input.
2220 Delete all characters from the cursor to the end of the line.
2224 \*(OP Go to the next history entry.
2229 \*(OP Go to the previous history entry.
2231 \*(OP Complete the current line from (the remaining older) history entries.
2238 Delete the characters from the one preceding the cursor to the preceding
2241 Move the cursor forward one word boundary.
2243 Move the cursor backward one word boundary.
2247 If the keycodes are known then the left and right cursor keys will map to
2251 respectively, the up and down cursor keys will map to
2255 and the Home/End/PgUp/PgDown keys will call the
2257 command with the respective arguments
2263 (i.e., perform scrolling through the header summary list).
2264 Also the up and down cursor keys should invoke
2266 for up- and downwards movement if they are used while the
2271 .\" .Ss "Coloured display" {{{
2272 .Ss "Coloured display"
2274 \*(OP \*(UA can be configured to support a coloured display and font
2275 attributes by emitting ANSI / ISO 6429 SGR (select graphic rendition)
2277 Usage of colours and font attributes solely depends upon the
2278 capability of the detected terminal type that is defined by the
2279 environment variable
2281 and which can be fine-tuned by the user via the internal variable
2285 On top of what \*(UA knows about the terminal the boolean variable
2287 defines wether the actually applicable colour and font attribute
2288 sequences should also be generated when output is going to be paged
2289 through the external program defined by the environment variable
2294 This is not enabled by default because different pager programs need
2295 different command line switches or other configuration in order to
2296 support those sequences.
2297 \*(UA however knows about some widely used pagers and in a clean
2298 environment it is often enough to simply set
2300 please refer to that variable for more on this topic.
2305 is set then any active usage of colour and font attribute sequences
2306 is suppressed, but without affecting possibly established
2311 To define and control colours and font attributes a single multiplexer
2312 command family exists:
2314 shows or defines colour mappings for the given colour type (e.g.,
2317 can be used to remove mappings of a given colour type.
2318 Since colours are only available in interactive mode, it may make
2319 sense to conditionalize the colour setup by encapsulating it with
2322 .Bd -literal -offset indent
2323 if terminal && $features =@ +colour
2324 colour iso view-msginfo ft=bold,fg=green
2325 colour iso view-header ft=bold,fg=red "from,subject"
2326 colour iso view-header fg=red
2328 uncolour iso view-header from,subject
2329 colour iso view-header ft=bold,fg=magenta,bg=cyan
2330 colour 256 view-header ft=bold,fg=208,bg=230 subject,from
2331 colour mono view-header ft=bold
2332 colour mono view-header ft=bold,ft=reverse subject,from
2336 .\" }}} (DESCRIPTION)
2339 .\" .Sh COMMANDS {{{
2342 Each command is typed on a line by itself,
2343 and may take arguments following the command word.
2344 The command need not be typed in its entirety \(en
2345 the first command which matches the typed prefix is used.
2346 An \(en alphabetically \(en sorted list of commands can be shown
2353 when given an argument, will show a documentation string for the
2354 command matching the expanded argument, as in
2356 which should be a shorthand of
2358 documentation strings are however \*(OPal.
2361 For commands which take message lists as arguments, the next message
2362 forward that satisfies the command's requirements will be used shall no
2363 explicit message list have been specified.
2364 If there are no messages forward of the current message,
2365 the search proceeds backwards,
2366 and if there are no good messages at all,
2368 .Dq no applicable messages
2369 and aborts the command.
2370 The arguments to commands can be quoted, using the following methods:
2373 .Bl -bullet -compact -offset indent
2375 An argument can be enclosed between paired double-quotes
2380 any white space, shell word expansion, or backslash characters (except
2381 as described next) within the quotes are treated literally as part of
2383 A double-quote will be treated literally within single-quotes and vice
2385 Inside such a quoted string the actually used quote character can be
2386 used nonetheless by escaping it with a backslash
2392 An argument that is not enclosed in quotes, as above, can usually still
2393 contain space characters if those spaces are backslash-escaped, as in
2397 A backslash outside of the enclosing quotes is discarded
2398 and the following character is treated literally as part of the argument.
2401 An unquoted backslash at the end of a command line is discarded and the
2402 next line continues the command.
2406 Filenames, where expected, are subsequently subjected to the following
2407 transformations, in sequence:
2410 .Bl -bullet -compact -offset indent
2412 If the filename begins with an unquoted plus sign, and the
2414 variable is defined,
2415 the plus sign will be replaced by the value of the
2417 variable followed by a slash.
2420 variable is unset or is set to null, the filename will be unchanged.
2423 Shell word expansions are applied to the filename.
2424 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2425 .Sy Compatibility note:
2426 on the long run support for complete shell word expansion will be
2427 replaced by an internally implemented restricted expansion mechanism in
2428 order to circumvent possible security impacts through shell expansion.
2429 Expect that a growing number of program parts only support this
2432 Meta expansions are applied to the filename: leading tilde characters
2434 will be replaced by the expansion of
2436 and any occurrence of
2440 will be replaced by the expansion of the variable, if possible;
2441 \*(UA internal as well as environmental (shell) variables can be
2442 accessed through this mechanism.
2443 In order to include a raw
2445 character precede it with a backslash
2447 to include a backslash double it.
2448 If more than a single pathname results from this expansion and the
2449 command is expecting one file, an error results.
2451 Note that in interactive display context, in order to allow simple
2452 value acceptance (typing
2454 backslash quoting is performed automatically as necessary, e.g., a file
2455 .Ql diet\e is \ecurd.txt
2456 will be displayed as
2457 .Ql diet\e\e is \e\ecurd.txt .
2461 The following commands are available:
2463 .Bl -tag -width ".Ic _ccount"
2470 ) command which follows.
2474 The comment-command causes the entire line to be ignored.
2476 this really is a normal command which' purpose is to discard its
2479 indicating special character, which means that, e.g., trailing comments
2480 on a line are not possible.
2484 Goes to the next message in sequence and types it
2490 Display the preceding message, or the n'th previous message if given
2491 a numeric argument n.
2495 Show the current message number (the
2500 Show a brief summary of commands.
2501 \*(OP Given an argument a synopsis for the command in question is
2502 shown instead; commands can be abbreviated in general and this command
2503 can be used to see the full expansion of an abbreviation including the
2504 synopsis, try, e.g.,
2509 and see how the output changes.
2519 Interprets the remainder of the word as a macro name and passes it
2524 is a shorter synonym for
2525 .Ql call Ar mymacro .
2529 (ac) Creates, selects or lists (an) account(s).
2530 An account is a group of commands and variable settings which together
2531 usually arrange the environment for the purpose of creating a system login.
2532 Without any argument a listing of all defined accounts and their content
2534 A specific account can be activated by giving solely its name, resulting
2535 in the system mailbox or inbox of that account to be activated as via an
2536 explicit use of the command
2538 The two argument form is identical to defining a macro as via
2541 .Bd -literal -offset indent
2545 set from="myname@myisp.example (My Name)"
2546 set smtp=smtp://mylogin@smtp.myisp.example
2550 creates an account named
2552 which can later be selected by specifying
2556 (case-insensitive) always exists.
2558 are enabled by default and localize account settings \(en different to
2559 normal macros the settings will be reverted once the account is switched off.
2560 Accounts can be deleted via
2565 (a) With no arguments, shows all currently-defined aliases.
2566 With one argument, shows that alias.
2567 With more than one argument,
2568 creates a new alias or appends to an existing one.
2570 can be used to delete aliases.
2574 (alt) Manage a list of alternate addresses / names of the active user,
2575 members of which will be removed from recipient lists when replying to
2578 variable is not set).
2579 If arguments are given the set of alternate names is replaced by them,
2580 without arguments the current set is displayed.
2584 Takes a message list and marks each message as having been answered.
2585 This mark has no technical meaning in the mail system;
2586 it just causes messages to be marked in the header summary,
2587 and makes them specially addressable.
2591 Calls a macro that has been created via
2596 (ch) Change the working directory to
2598 or the given argument.
2604 \*(OP Only applicable to S/MIME signed messages.
2605 Takes a message list and a file name and saves the certificates
2606 contained within the message signatures to the named file in both
2607 human-readable and PEM format.
2608 The certificates can later be used to send encrypted messages to the
2609 respective message senders by setting
2610 .Va smime-encrypt-USER@HOST
2615 (ch) Change the working directory to
2617 or the given argument.
2623 Only applicable to threaded mode.
2624 Takes a message list and makes all replies to these messages invisible
2625 in header summaries, unless they are in state
2631 \*(OP Manage colour mappings for the type of colour given as the
2632 (case-insensitive) first argument, which must be one of
2634 for 256-colour terminals,
2639 for the standard 8-colour ANSI / ISO 6429 color palette and
2643 for monochrome terminals.
2644 Monochrome terminals cannot deal with colours, but only (some) font
2648 Without further arguments the list of all currently defined mappings
2649 for the given colour type is shown (as a special case giving
2653 will iterate over all types in order).
2654 Otherwise the second argument defines the mappable slot, the third
2655 argument a (comma-separated list of) colour and font attribute
2656 specification(s), and the optional fourth argument can be used to
2657 specify a precondition: if conditioned mappings exist they are tested in
2658 (creation) order unless a (case-insensitive) match has been found, and
2659 the default mapping (if any has been established) will only be chosen as
2661 The types of precondition available depend on the mappable slot, the
2662 following of which exist:
2665 .Bl -tag -compact -width view-partinfo
2667 Mappings prefixed with
2669 are used in header summaries, and they all understand the preconditions
2671 (the current message) and
2673 for elder messages (only honoured in conjunction with
2674 .Va datefield-markout-older ) .
2675 This mapping is used for the
2677 that can be created with the
2681 formats of the variable
2684 For the complete header summary line except the
2686 and the thread structure.
2688 For the thread structure which can be created with the
2690 format of the variable
2694 Mappings prefixed with
2696 are used when displaying messages.
2697 This mapping is used for so-called
2699 lines, which are MBOX file format specific header lines.
2702 A comma-separated list of headers to which the mapping applies may be
2703 given as a precondition; if the \*(OPal regular expression support is
2704 available then if any of the
2706 (extended) regular expression characters is seen the precondition will
2707 be evaluated as (an extended) one.
2709 For the introductional message info line.
2710 .It Cd view-partinfo
2711 For MIME part info lines.
2715 The following (case-insensitive) colour definitions and font attributes
2716 are understood, multiple of which can be specified in a comma-separated
2726 It is possible (and often applicable) to specify multiple font
2727 attributes for a single mapping.
2730 foreground colour attribute:
2740 To specify a 256-color mode a decimal number colour specification in
2741 the range 0 to 255, inclusive, is supported, and interpreted as follows:
2743 .Bl -tag -compact -width "999 - 999"
2745 the standard ISO 6429 colors, as above.
2747 high intensity variants of the standard colors.
2749 216 colors in tuples of 6.
2751 grayscale from black to white in 24 steps.
2753 .Bd -literal -offset indent
2755 fg() { printf "\e033[38;5;${1}m($1)"; }
2756 bg() { printf "\e033[48;5;${1}m($1)"; }
2758 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
2759 printf "\e033[0m\en"
2761 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
2762 printf "\e033[0m\en"
2766 background colour attribute (see
2768 for possible values).
2772 Mappings may be removed with the command
2774 For a generic overview see the section
2775 .Sx "Coloured display" .
2780 (C) Copy messages to files whose names are derived from the author of
2781 the respective message and don't mark them as being saved;
2782 otherwise identical to
2787 (c) Copy messages to the named file and don't mark them as being saved;
2788 otherwise identical to
2793 With no arguments, shows all currently-defined custom headers.
2794 With one argument, shows that custom header.
2795 With more than one argument, creates a new or replaces an existing
2796 custom header with the name given as the first argument, the content of
2797 which being defined by the concatenated remaining arguments.
2799 can be used to delete custom headers.
2800 \*(ID Overwriting of automatically managed headers is neither supported
2802 Defined custom headers will be injected into newly composed or forwarded
2805 .Dl customhdr OpenPGP id=12345678; url=http://www.YYY.ZZ
2809 may also be used to inject custom headers; it is covered by
2814 Show the name of the current working directory.
2818 \*(OP For unencrypted messages this command is identical to
2820 Encrypted messages are first decrypted, if possible, and then copied.
2824 \*(OP For unencrypted messages this command is identical to
2826 Encrypted messages are first decrypted, if possible, and then copied.
2830 Without arguments the current list of macros, including their content,
2831 is shown, otherwise a macro is defined.
2832 A macro definition is a sequence of commands in the following form:
2833 .Bd -literal -offset indent
2842 A defined macro can be invoked explicitly by using the
2846 commands, or implicitly if a macro hook is triggered, e.g., a
2848 Note that interpretation of
2850 depends on how (i.e.,
2852 normal macro, folder hook, hook, account switch) the macro is invoked.
2853 Macros can be deleted via
2857 Macro behaviour, including option localization, will change in v15.
2858 Please be aware of that and possibly embed a version check in a resource
2863 (d) Marks the given message list as
2865 Deleted messages will neither be saved in
2867 nor will they be available for most other commands.
2879 Deletes the current message and displays the next message.
2880 If there is no next message, \*(UA says
2887 up or down by one message when given
2891 argument, respectively.
2895 Takes a message list and marks each given message as a draft.
2896 This mark has no technical meaning in the mail system;
2897 it just causes messages to be marked in the header summary,
2898 and makes them specially addressable.
2902 (ec) Echoes its arguments,
2903 resolving special names as documented for the command
2905 The escape sequences
2917 are interpreted just as they are by
2919 (proper quoting provided).
2923 (e) Point the text editor (as defined in
2925 at each message from the given list in turn.
2926 Modified contents are discarded unless the
2933 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2934 conditional \(em if the condition of a preceeding
2936 was false, check the following condition and execute the following block
2937 if it evaluates true.
2942 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2943 conditional \(em if none of the conditions of the preceeding
2947 commands was true, the
2953 (en) Marks the end of an
2954 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2955 conditional execution block.
2959 \*(OP Since \*(UA uses the console as a user interface it can happen
2960 that messages scroll by too fast to become recognized.
2961 Optionally an error message ring queue is available which stores
2962 duplicates of any error message and notifies the user in interactive
2963 sessions whenever a new error has occurred.
2964 The queue is finite: if its maximum size is reached any new message
2965 replaces the eldest.
2968 can be used to manage this message queue: if given
2970 or no argument the queue will be displayed and cleared,
2972 will only clear all messages from the queue.
2976 (ex or x) Exit from \*(UA without changing the active mailbox and skip
2977 any saving of messages in
2979 as well as a possibly tracked line editor history file.
2983 Show the list of features that have been compiled into \*(UA.
2984 (Outputs the contents of the variable
2991 but open the mailbox readonly.
2995 (fi) The file command switches to a new mailbox.
2996 Without arguments it shows status information of the current mailbox.
2997 If an argument is given, it will write out changes (such as deletions)
2998 the user has made and open a new mailbox.
2999 Some special conventions are recognized for the
3003 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
3005 (number sign) means the previous file,
3007 (percent sign) means the invoking user's system mailbox,
3009 means the system mailbox of
3011 (and never the value of
3013 regardless of its actual setting),
3015 (ampersand) means the invoking user's
3025 expands to the same value as
3027 but the file is handled as a system mailbox by, e.g., the
3031 commands, meaning that messages that have been read in the current
3032 session will be moved to the
3034 mailbox instead of simply being flagged as read.
3037 If the name matches one of the strings defined with the command
3039 it is replaced by its long form and expanded.
3040 If the name ends with
3045 it is treated as being compressed with
3050 respectively, and transparently handled through an intermediate
3051 (un)compression step (using a temporary file) with the according
3052 facility, sufficient support provided.
3053 Likewise, if the named file doesn't exist, but a file with one of the
3054 mentioned compression extensions does, then the name is automatically
3055 expanded and the compressed file is used.
3057 Otherwise, if the name ends with an extension for which
3058 .Va file-hook-load-EXTENSION
3060 .Va file-hook-save-EXTENSION
3061 variables are set, then the given hooks will be used to load and save
3063 and \*(UA will work with an intermediate temporary file.
3065 MBOX files (flat file-based mailboxes) are generally locked during file
3066 operations in order to avoid inconsistencies due to concurrent
3068 \*(OPal Mailbox files which \*(UA treats as system or primary mailboxes
3069 will also be protected by so-called dotlock files, the traditional way
3070 of mail spool file locking: for any file
3074 will be created for the duration of the synchronization \(em
3075 as necessary a privilege-separated dotlock child process will be used
3076 to accommodate for necessary privilege adjustments in order to create
3077 the dotlock file in the same directory
3078 and with the same user and group identities as the file of interest.
3081 for fine-tuning the handling of MBOX files.
3085 refers to a directory with the subdirectories
3090 then it is treated as a folder in
3095 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3096 .Dl \*(OU protocol://[user@]host[:port][/path]
3098 is taken as an Internet mailbox specification.
3099 The \*(OPally supported protocols are
3103 (POP3 with SSL/TLS encrypted transport).
3106 part is valid only for IMAP; there it defaults to
3108 Also see the section
3109 .Sx "On URL syntax and credential lookup" .
3113 contains special characters, in particular
3117 they must be escaped in URL notation \(en the command
3119 can be used to show the necessary conversion.
3123 Takes a message list and marks the messages as
3125 ged for urgent/special attention.
3126 This mark has no technical meaning in the mail system;
3127 it just causes messages to be highlighted in the header summary,
3128 and makes them specially addressable.
3137 With no arguments, list the names of the folders in the folder directory.
3138 With an existing folder as an argument,
3139 lists the names of folders below the named folder.
3145 but saves the message in a file named after the local part of the first
3146 recipient's address (instead of in
3153 but saves the message in a file named after the local part of the first
3154 recipient's address (instead of in
3161 but responds to all recipients regardless of the
3166 .It Ic followupsender
3169 but responds to the sender only regardless of the
3185 (f) Takes a list of message specifications and displays a summary of
3186 their message headers, as via
3188 An alias of this command is
3191 .Sx "Specifying messages" .
3197 but saves the message in a file named after the local part of the
3198 recipient's address (instead of in
3203 Takes a message and the address of a recipient
3204 and forwards the message to him.
3205 The text of the original message is included in the new one,
3206 with the value of the
3208 variable preceding it.
3213 commands specify which header fields are included in the new message.
3214 Only the first part of a multipart message is included unless the
3215 .Va forward-as-attachment
3219 is set recipient addresses will be stripped from comments, names etc.
3223 Specifies which header fields are to be ignored with the command
3225 This command has no effect when the
3226 .Va forward-as-attachment
3231 Specifies which header fields are to be retained with the command
3236 This command has no effect when the
3237 .Va forward-as-attachment
3242 Define or list command aliases, so-called ghosts.
3243 Without arguments a list of all currently known aliases is shown.
3244 With one argument the expansion of the given alias is shown.
3245 With two or more arguments a command alias is defined or updated: the
3246 first argument is the name under which the remaining command line should
3247 be accessible, the content of which can be just about anything.
3248 A ghost can be used everywhere a normal command can be used, but always
3249 takes precedence; any arguments that are given to the command alias are
3250 joined onto the alias content, and the resulting string forms the
3251 command line that is, in effect, executed.
3254 .Bd -literal -offset indent
3256 `ghost': no such alias: "xx"
3259 ghost xx "echo hello,"
3268 (h) Show the current group of headers, the size of which depends on
3271 and the style of which can be adjusted with the variable
3273 If a message-specification is given the group of headers containing the
3274 first message therein is shown and the message at the top of the screen
3289 the list of history entries;
3292 argument selects and shows the respective history entry \(en
3295 to accept it, and the history entry will become the new history top.
3296 The default mode if no arguments are given is
3303 Takes a message list and marks each message therein to be saved in the
3304 user's system mailbox instead of in
3306 Does not override the
3309 \*(UA deviates from the POSIX standard with this command, because a
3311 command issued after
3313 will display the following message, not the current one.
3318 (i) Part of the nestable
3319 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3320 conditional execution construct \(em if the given condition is true then
3321 the encapsulated block is executed.
3322 POSIX only supports the (case-insensitive) conditions
3327 end, all remaining conditions are non-portable extensions; note that
3328 falsely specified conditions cause the execution of the entire
3329 conditional construct until the (matching) closing
3331 command to be suppressed.
3332 The syntax of the nestable
3334 conditional execution construct requires that each condition and syntax
3335 element is surrounded by whitespace.
3337 .Bd -literal -offset indent
3346 The (case-insensitive) condition
3348 erminal will evaluate to true if the standard input is a terminal, i.e.,
3349 in interactive sessions.
3350 Another condition can be any boolean value (see the section
3351 .Sx "INTERNAL VARIABLES"
3352 for textual boolean representations) to mark an enwrapped block as
3355 .Dq always execute .
3356 It is possible to check
3357 .Sx "INTERNAL VARIABLES"
3360 variables for existence or compare their expansion against a user given
3361 value or another variable by using the
3363 .Pf ( Dq variable next )
3364 conditional trigger character;
3365 a variable on the right hand side may be signalled using the same
3367 The variable names may be enclosed in a pair of matching braces.
3370 The available comparison operators are
3374 (less than or equal to),
3380 (greater than or equal to),
3384 (is substring of) and
3386 (is not substring of).
3387 The values of the left and right hand side are treated as strings and
3388 are compared 8-bit byte-wise, ignoring case according to the rules of
3389 the US-ASCII encoding (therefore, dependend on the active locale,
3390 possibly producing false results for strings in the locale encoding).
3391 Except for the substring checks the comparison will instead be performed
3392 arithmetically if both, the user given value as well as the variable
3393 content, can be parsed as numbers (integers).
3394 An unset variable is treated as the empty string.
3397 When the \*(OPal regular expression support is available, the additional
3403 They treat the right hand side as an extended regular expression that is
3404 matched case-insensitively and according to the active
3406 locale, meaning that strings in the locale encoding should be matched
3410 Conditions can be joined via AND-OR lists (where the AND operator is
3412 and the OR operator is
3414 which have equal precedence and will be evaluated with left
3415 associativity, thus using the same syntax that is known for the
3417 It is also possible to form groups of conditions and lists by enclosing
3418 them in pairs of brackets
3419 .Ql [\ \&.\&.\&.\ ] ,
3420 which may be interlocked within each other, and also be joined via
3424 The results of individual conditions and entire groups may be modified
3425 via unary operators: the unary operator
3427 will reverse the result.
3429 .Bd -literal -offset indent
3433 if $ttycharset == "UTF-8"
3434 echo *ttycharset* is set to UTF-8, case-insensitively
3438 echo These two variables are equal
3440 if $version-major >= 15
3441 echo Running a new version..
3442 if $features =@ "regex"
3443 if $TERM =~ "^xterm\&.*"
3444 echo ..in an X terminal
3447 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
3450 if true && $debug || ${verbose}
3451 echo Left associativity, as is known from the shell
3453 if ! ! true && ! [ ! $debug && ! $verbose ]
3454 echo Unary operator support
3462 Without arguments the list of ignored header fields is shown,
3463 otherwise the given list of header fields is added to the ignore list:
3464 Header fields in the ignore list are not shown on the terminal when
3465 a message is displayed.
3466 To display a message in its entirety, use the commands
3477 Shows the names of all available commands, alphabetically sorted.
3481 This command can be used to localize changes to variables, meaning that
3482 their state will be reverted to the former one once the covered scope
3484 It can only be used inside of macro definition blocks introduced by
3488 and is interpreted as a boolean (string, see
3489 .Sx "INTERNAL VARIABLES" ) ;
3492 of an account is left once it is switched off again.
3493 .Bd -literal -offset indent
3494 define temporary_settings {
3509 enables change localization and calls
3511 which explicitly resets localization, then any value changes within
3513 will still be reverted by
3518 Reply to messages that come in via known
3521 .Pf ( Ic mlsubscribe )
3522 mailing lists, or pretend to do so (see
3523 .Sx "Mailing lists" ) :
3526 functionality this will actively resort and even remove message
3527 recipients in order to generate a message that is supposed to be sent to
3529 For example it will also implicitly generate a
3530 .Ql Mail-Followup-To:
3531 header if that seems useful, regardless of the setting of the variable
3538 but saves the message in a file named after the local part of the first
3539 recipient's address (instead of in
3544 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3545 or asks on standard input if none were given;
3546 then collects the remaining mail content and sends it out.
3550 (mb) The given message list is to be sent to
3552 when \*(UA is quit; this is the default action unless the
3555 \*(ID This command can only be used in a system mailbox (see
3560 Without any arguments the content of the MIME type cache will displayed.
3561 Otherwise each argument defines a complete MIME type specification of
3562 a type that shall be added (prepended) to the cache.
3563 In any event MIME type sources are loaded first as necessary \(en
3564 .Va mimetypes-load-control
3565 can be used to fine-tune which sources are actually loaded.
3566 Refer to the section on
3567 .Sx "The mime.types files"
3568 for more on MIME type specifications and this topic in general.
3569 MIME type unregistration and cache resets can be triggered with
3574 Without arguments the list of all currently defined mailing lists
3575 (and their attributes, if any) is shown; a more verbose listing will be
3576 produced if either of
3581 Otherwise all given arguments (which need not be quoted except for
3582 whitespace) will be added and henceforth be recognized as mailing lists.
3583 Mailing lists may be removed via the command
3586 If the \*(OPal regular expression support is available then mailing
3587 lists may also be specified as (extended) regular expressions (see
3593 Without arguments the list of all currently defined mailing lists which
3594 have a subscription attribute is shown; a more verbose listing will be
3595 produced if either of
3600 Otherwise this attribute will be set for all given mailing lists,
3601 newly creating them as necessary (as via
3603 Subscription attributes may be removed via the command
3612 but moves the messages to a file named after the local part of the
3613 sender address of the first message (instead of in
3620 but marks the messages for deletion if they were transferred
3627 but also displays ignored header fields and all MIME parts.
3635 on the given messages, even in non-interactive mode and as long as the
3636 standard output is a terminal.
3642 \*(OP When used without arguments or if
3644 has been given the content of the
3646 cache is shown, loading it first as necessary,
3649 then the cache will only be initialized and
3651 will remove its contents.
3652 Note that \*(UA will try to load the file only once, use
3653 .Ql Ic netrc Ns \:\0\:clear
3654 to unlock further attempts.
3658 .Sx "On URL syntax and credential lookup" ;
3660 .Sx "The .netrc file"
3661 documents the file format in detail.
3665 Checks for new mail in the current folder without committing any changes
3667 If new mail is present, a message is shown.
3671 the headers of each new message are also shown.
3679 Goes to the next message in sequence and types it.
3680 With an argument list, types the next matching message.
3694 If the current folder is accessed via a network connection, a
3696 command is sent, otherwise no operation is performed.
3702 but also displays ignored header fields and all MIME parts.
3710 on the given messages, even in non-interactive mode and as long as the
3711 standard output is a terminal.
3719 but also pipes ignored header fields and all parts of MIME
3720 .Ql multipart/alternative
3725 (pi) Takes a message list and a shell command
3726 and pipes the messages through the command.
3727 Without an argument the current message is piped through the command
3734 every message is followed by a formfeed character.
3755 (q) Terminates the session, saving all undeleted, unsaved messages in
3758 preserving all messages marked with
3762 or never referenced in the system mailbox,
3763 and removing all other messages from the system mailbox.
3764 If new mail has arrived during the session,
3766 .Dq You have new mail
3768 If given while editing a mailbox file with the command line flag
3770 then the edit file is rewritten.
3771 A return to the shell is effected,
3772 unless the rewrite of edit file fails,
3773 in which case the user can escape with the exit command.
3787 Removes the named folders.
3788 The user is asked for confirmation in interactive mode.
3792 Takes the name of an existing folder
3793 and the name for the new folder
3794 and renames the first to the second one.
3795 Both folders must be of the same type.
3799 (R) Reply to originator.
3800 Does not reply to other recipients of the original message.
3802 will exchange this command with
3806 is set the recipient address will be stripped from comments, names etc.
3810 (r) Take a message and group-responds to it by addressing the sender
3813 .Va followup-to-honour ,
3816 .Va recipients-in-cc
3817 influence response behaviour.
3820 offers special support for replying to mailing lists.
3823 is set recipient addresses will be stripped from comments, names etc.
3836 but initiates a group-reply regardless of the value of
3843 but responds to the sender only regardless of the value of
3850 but does not add any header lines.
3851 This is not a way to hide the sender's identity,
3852 but useful for sending a message again to the same recipients.
3856 Takes a list of messages and a user name
3857 and sends each message to the named user.
3859 and related header fields are prepended to the new copy of the message.
3877 .It Ic respondsender
3883 (ret) Without arguments the list of retained header fields is shown,
3884 otherwise the given list of header fields is added to the retain list:
3885 Header fields in the retain list are shown on the terminal when
3886 a message is displayed, all other header fields are suppressed.
3887 To display a message in its entirety, use the commands
3896 takes precedence over the mentioned.
3902 but saves the messages in a file named after the local part of the
3903 sender of the first message instead of (in
3905 and) taking a filename argument.
3909 (s) Takes a message list and a filename and appends each message in turn
3910 to the end of the file.
3911 If no filename is given, the
3914 The filename in quotes, followed by the generated character count
3915 is echoed on the user's terminal.
3916 If editing a system mailbox the messages are marked for deletion.
3917 Filename interpretation as described for the
3919 command is performed.
3936 Header fields thus marked are filtered out when saving a message by
3938 or when automatically saving to
3940 This command should only be applied to header fields that do not contain
3941 information needed to decode the message,
3942 as MIME content fields do.
3954 Header fields thus marked are the only ones saved with a message when
3957 or when automatically saving to
3962 The use of this command is strongly discouraged since it may strip
3963 header fields that are needed to decode the message correctly.
3967 Takes a message specification (list) and displays a header summary of
3968 all matching messages, as via
3970 This command is an alias of
3973 .Sx "Specifying messages" .
3977 Takes a message list and marks all messages as having been read.
3981 (se) Without arguments this command shows all variables and their
3982 values which are currently known to \*(UA.
3983 Setting any of the variables
3987 changes the output format to BSD style, otherwise a properly quoted
3988 listing is produced.
3993 has been set twice then the listing is modified to mark out assembled
3996 Otherwise modifies (set and unsets) the given variables.
3997 Arguments are of the form
3999 (no space before or after
4003 if there is no value.
4004 Quotation marks may be placed around any part of the assignment
4005 statement to quote blanks or tabs, e.g.,
4007 .Dl set indentprefix="->"
4009 If an argument begins with
4013 the effect is the same as invoking the
4015 command with the remaining part of the variable
4016 .Pf ( Ql unset save ) .
4022 except that the variables are also exported into the program environment;
4023 since this task requires native host support the command will always
4024 report error if that is not available (but still act like
4027 This operation is a no-op unless all resource files have been loaded.
4033 (sh) Invokes an interactive version of the shell.
4037 Without arguments the list of all currently defined shortcuts is
4039 Otherwise all given arguments (which need not be quoted except for
4040 whitespace) are treated as pairs of shortcuts and their expansions,
4041 creating new or changing already existing shortcuts, as necessary.
4042 Shortcuts may be removed via the command
4044 The expansion strings should be in the syntax that has been described
4053 but performs neither MIME decoding nor decryption, so that the raw
4054 message text is shown.
4058 (si) Shows the size in characters of each message of the given
4063 Shows the current sorting criterion when used without an argument.
4064 Otherwise creates a sorted representation of the current folder,
4067 command and the addressing modes such that they refer to messages in
4069 Message numbers are the same as in regular mode.
4073 a header summary in the new order is also displayed.
4074 Automatic folder sorting can be enabled by setting the
4076 variable, as in, e.g.,
4077 .Ql set autosort=thread .
4078 Possible sorting criterions are:
4080 .Bl -tag -compact -offset indent -width "subject"
4082 Sort the messages by their
4084 field, that is by the time they were sent.
4086 Sort messages by the value of their
4088 field, that is by the address of the sender.
4091 variable is set, the sender's real name (if any) is used.
4093 Sort the messages by their size.
4095 \*(OP Sort the message by their spam score, as has been classified by
4098 Sort the messages by their message status.
4100 Sort the messages by their subject.
4102 Create a threaded display.
4104 Sort messages by the value of their
4106 field, that is by the address of the recipient.
4109 variable is set, the recipient's real name (if any) is used.
4114 (so) The source command reads commands from the given file, which is
4115 subject to the usual filename expansions (see introductional words of
4117 If the given argument ends with a vertical bar
4119 then the argument will instead be interpreted as a shell command and
4120 \*(UA will read the output generated by it.
4126 (beside not supporting pipe syntax a.k.a. shell command input) is that
4127 this command will not generate an error if the given file argument
4128 cannot be opened successfully.
4129 This can matter in, e.g., resource files, since loading of those is
4130 stopped when an error is encountered.
4134 \*(OP Takes a list of messages and clears their
4140 \*(OP Takes a list of messages and causes the
4142 to forget it has ever used them to train its Bayesian filter.
4143 Unless otherwise noted the
4145 flag of the message is inspected to chose wether a message shall be
4153 \*(OP Takes a list of messages and informs the Bayesian filter of the
4157 This also clears the
4159 flag of the messages in question.
4163 \*(OP Takes a list of messages and rates them using the configured
4164 .Va spam-interface ,
4165 without modifying the messages, but setting their
4167 flag as appropriate; because the spam rating headers are lost the rate
4168 will be forgotten once the mailbox is left.
4169 Refer to the manual section
4171 for the complete picture of spam handling in \*(UA.
4175 \*(OP Takes a list of messages and sets their
4181 \*(OP Takes a list of messages and informs the Bayesian filter of the
4187 flag of the messages in question.
4196 Create a threaded representation of the current folder,
4197 i.\|e. indent messages that are replies to other messages in the header
4198 display and change the
4200 command and the addressing modes such that they refer to messages in the
4202 Message numbers are the same as in unthreaded mode.
4206 a header summary in threaded order is also displayed.
4210 (to) Takes a message list and displays the top few lines of each.
4211 The number of lines shown is controlled by the variable
4213 and defaults to five.
4217 (tou) Takes a message list and marks the messages for saving in
4219 \*(UA deviates from the POSIX standard with this command,
4222 command will display the following message instead of the current one.
4228 but also displays out ignored header fields and all parts of MIME
4229 .Ql multipart/alternative
4234 (t) Takes a message list and types out each message on the user's
4240 For MIME multipart messages, all parts with a content type of
4244 are shown, the other are hidden except for their headers.
4245 Messages are decrypted and converted to the terminal character set
4250 Delete all given accounts.
4251 An error message is shown if a given account is not defined.
4254 will discard all existing accounts.
4258 (una) Takes a list of names defined by alias commands
4259 and discards the remembered groups of users.
4262 will discard all existing aliases.
4266 Takes a message list and marks each message as not having been answered.
4270 Only applicable to threaded mode.
4271 Takes a message list and makes the message and all replies to it visible
4272 in header summaries again.
4273 When a message becomes the current message,
4274 it is automatically made visible.
4275 Also when a message with collapsed replies is displayed,
4276 all of these are automatically uncollapsed.
4282 mapping for the given colour type (see
4284 for a list of types) and mapping; if the optional precondition argument
4285 is used then only the exact tuple of mapping and precondition is removed.
4288 will remove all mappings (no precondition allowed).
4290 .Sx "Coloured display"
4291 for the general picture.
4295 Deletes the custom headers given as arguments.
4298 will remove all custom headers.
4302 Undefine all given macros.
4303 An error message is shown if a given macro is not defined.
4306 will discard all existing macros.
4310 (u) Takes a message list and marks each message as not being deleted.
4314 Takes a message list and
4320 Takes a message list and marks each message as not being
4325 Removes the header field names from the list of ignored fields for the
4330 will remove all fields.
4334 Removes the header field names from the list of retained fields for the
4339 will remove all fields.
4343 Remove all the given command
4347 will remove all ghosts.
4351 Removes the header field names from the list of ignored fields.
4354 will remove all fields.
4358 Delete all given MIME types, e.g.,
4359 .Ql unmimetype text/plain
4360 will remove all registered specifications for the MIME type
4364 will discard all existing MIME types, just as will
4366 but which also reenables cache initialization via
4367 .Va mimetypes-load-control .
4371 Forget about all the given mailing lists.
4374 will remove all lists.
4379 .It Ic unmlsubscribe
4380 Remove the subscription attribute from all given mailing lists.
4383 will clear the attribute from all lists which have it set.
4394 Takes a message list and marks each message as not having been read.
4398 Removes the header field names from the list of retained fields.
4401 will remove all fields.
4405 Removes the header field names from the list of ignored fields for
4409 will remove all fields.
4413 Removes the header field names from the list of retained fields for
4417 will remove all fields.
4421 (uns) Takes a list of option names and discards their remembered values;
4429 except that the variables are also removed from the program environment;
4430 since this task requires native host support the command will always
4431 report error if that is not available (but still act like
4434 This operation is a no-op unless all resource files have been loaded.
4440 Deletes the shortcut names given as arguments.
4443 will remove all shortcuts.
4447 Disable sorted or threaded mode
4453 return to normal message order and,
4457 displays a header summary.
4467 Decode the given URL-encoded string arguments and show the results.
4468 Note the resulting strings may not be valid in the current locale, see
4473 URL-encode the given arguments and show the results.
4474 Because the arguments effectively are in the character set of the
4475 current locale the results will vary accordingly unless the input solely
4476 consists of characters in the portable character set, see
4477 .Sx "Character sets" .
4481 Edit the values of or create the given variable(s) in the
4483 Boolean variables cannot be edited.
4487 Show informations about all the given variables.
4488 \*(UA knows about a finite set of known builtin variables that are
4489 subdivided further in boolean and value variants;
4490 they may have special properties, like
4492 (setting may not be changed) and
4494 meaning that the value is generated on-the-fly as necessary.
4495 Beside those known variables an infinite number of unknown, so-called
4497 variables, which are expected to be able to store values, may exist.
4498 .Bd -literal -offset indent
4500 ? varshow sendwait version-major foo bar
4501 "sendwait": (73) boolean: set=1 (ENVIRON=0)
4502 "version-major": (192) value, read-only, virtual:\e
4503 set=1 (ENVIRON=0) value<14>
4504 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4505 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4510 \*(OP Takes a message list and verifies each message.
4511 If a message is not a S/MIME signed message,
4512 verification will fail for it.
4513 The verification process checks if the message was signed using a valid
4515 if the message sender's email address matches one of those contained
4516 within the certificate,
4517 and if the message content has been altered.
4521 (v) Takes a message list and invokes the display editor on each message.
4522 Modified contents are discarded unless the
4528 (w) For conventional messages the body without all headers is written.
4529 The output is decrypted and converted to its native format as necessary.
4530 If the output file exists, the text is appended.
4531 If a message is in MIME multipart format its first part is written to
4532 the specified file as for conventional messages,
4533 and the user is asked for a filename to save each other part.
4534 For convience saving of each part may be skipped by giving an empty value;
4535 the same result can also be achieved by writing it to
4537 For the second and subsequent parts a leading
4539 character causes the part to be piped to the remainder of the user input
4540 interpreted as a shell command;
4541 otherwise the user input is expanded as usually for folders,
4542 e.g., tilde expansion is performed.
4543 In non-interactive mode, only the parts of the multipart message
4544 that have a filename given in the part header are written,
4545 the others are discarded.
4546 The original message is never marked for deletion in the originating
4549 the contents of the destination file are overwritten if the file
4551 No special handling of compressed files is performed.
4560 \*(UA presents message headers in windowfuls as described under the
4563 This command scrolls to the next window of messages.
4564 If an argument is given,
4565 it specifies the window to use.
4566 A number prefixed by
4570 indicates that the window is calculated in relation to the current position.
4571 A number without a prefix specifies an absolute window number,
4574 lets \*(UA scroll to the last window of messages.
4580 but scrolls to the next or previous window that contains at least one
4589 .\" .Sh TILDE ESCAPES {{{
4592 Here is a summary of the tilde escapes,
4593 which are used to perform special functions when composing messages.
4594 Tilde escapes are only recognized at the beginning of lines.
4597 is somewhat of a misnomer since the actual escape character can be
4598 changed by adjusting the option
4601 .Bl -tag -width ".Ic __ filename"
4604 Insert the string of text in the message prefaced by a single
4606 (If the escape character has been changed,
4607 that character must be doubled
4608 in order to send it at the beginning of a line.)
4611 .It Ic ~! Ar command
4612 Execute the indicated shell
4614 then return to the message.
4618 Same effect as typing the end-of-file character.
4621 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4622 Execute the given \*(UA command.
4623 Not all commands, however, are allowed.
4627 Write a summary of command escapes.
4630 .It Ic ~< Ar filename
4635 .It Ic ~<! Ar command
4637 is executed using the shell.
4638 Its standard output is inserted into the message.
4641 .It Ic ~@ Op Ar filename...
4642 With no arguments, edit the attachment list interactively.
4643 If an attachment's file name is left empty,
4644 that attachment is deleted from the list.
4645 When the end of the attachment list is reached,
4646 \*(UA will ask for further attachments until an empty name is given.
4647 If a given file name solely consists of the number sign
4649 followed by a valid message number of the currently active mailbox, then
4650 the given message is attached as a MIME
4652 and the rest of this section does not apply.
4654 If character set conversion has been compiled into \*(UA, then this mode
4655 gives the user the option to specify input and output character sets,
4656 unless the file extension indicates binary content, in which case \*(UA
4657 asks wether this step shall be skipped for the attachment in question.
4658 If not skipped, then the charset that succeeds to represent the
4659 attachment data will be used in the
4661 MIME parameter of the mail message:
4663 .Bl -bullet -compact
4665 If input and output character sets are specified, then the conversion is
4666 performed on the fly.
4667 The user will be asked repeatedly until the desired conversion succeeds.
4669 If only an output character set is specified, then the input is assumed
4672 charset and will be converted to the given output charset on the fly.
4673 The user will be asked repeatedly until the desired conversion succeeds.
4675 If no character sets are specified at all then the algorithm that is
4676 documented in the section
4677 .Sx "Character sets"
4678 is applied, but directly and on the fly.
4679 The user will be asked repeatedly until the desired conversion succeeds.
4681 Finally, if an input-, but no output character set is specified, then no
4682 conversion is ever performed, but the
4684 MIME parameter value will still be set to the user input.
4686 The character set selection loop can be left by typing
4688 i.e., causing an interrupt.
4689 .\" \*(OU next sentence
4690 Note that before \*(UA version 15.0 this terminates the entire
4691 current attachment selection, not only the character set selection.
4694 Without character set conversion support, \*(UA will ask for the input
4695 character set only, and it'll set the
4697 MIME parameter value to the given input, if any;
4698 if no user input is seen then the
4700 character set will be used for the parameter value instead.
4701 Note that the file extension check isn't performed in this mode, since
4702 no conversion will take place anyway.
4704 Note that in non-interactive mode, for reproduceabilities sake, there
4705 will always be two questions for each attachment, regardless of wether
4706 character set conversion is available and what the file extension is.
4707 The first asks for the filename, and the second asks for the input
4708 character set to be passed through to the corresponding MIME parameter;
4709 no conversion will be tried if there is input to the latter question,
4710 otherwise the usual conversion algorithm, as above, is applied.
4711 For message attachments, the answer to the second question is completely
4716 arguments are specified for the
4718 command they are treated as a comma-separated list of files,
4719 which are all expanded and appended to the end of the attachment list.
4720 (Commas need to be escaped with backslash, but filenames with leading or
4721 trailing whitespace can only be added via the command line or the first
4723 Message attachments can only be added via the first method;
4724 filenames which clash with message numbers can only be added via the
4725 command line or the second method.)
4726 In this mode the (text) attachments are assumed to be in
4728 encoding, and will be evaluated as documented in the section
4729 .Sx "Character sets" .
4733 Inserts the string contained in the
4736 .Ql Ic ~i Ns \0Sign ) .
4737 The escape sequences tabulator
4745 Inserts the string contained in the
4748 .Ql Ic ~i Ns \0sign ) .
4749 The escape sequences tabulator
4756 .It Ic ~b Ar name ...
4757 Add the given names to the list of blind carbon copy recipients.
4760 .It Ic ~c Ar name ...
4761 Add the given names to the list of carbon copy recipients.
4765 Read the file specified by the
4767 variable into the message.
4771 Invoke the text editor on the message collected so far.
4772 After the editing session is finished,
4773 the user may continue appending text to the message.
4776 .It Ic ~F Ar messages
4777 Read the named messages into the message being sent, including all
4778 message headers and MIME parts.
4779 If no messages are specified, read in the current message.
4782 .It Ic ~f Ar messages
4783 Read the named messages into the message being sent.
4784 If no messages are specified, read in the current message.
4788 lists are used to modify the message headers.
4789 For MIME multipart messages,
4790 only the first displayable part is included.
4794 Edit the message header fields
4799 by typing each one in turn and allowing the user to edit the field.
4800 The default values for these fields originate from the
4808 Edit the message header fields
4814 by typing each one in turn and allowing the user to edit the field.
4817 .It Ic ~i Ar variable
4818 Insert the value of the specified variable into the message,
4819 adding a newline character at the end.
4820 The message remains unaltered if the variable is unset or empty.
4821 The escape sequences tabulator
4828 .It Ic ~M Ar messages
4829 Read the named messages into the message being sent,
4832 If no messages are specified, read the current message.
4835 .It Ic ~m Ar messages
4836 Read the named messages into the message being sent,
4839 If no messages are specified, read the current message.
4843 lists are used to modify the message headers.
4844 For MIME multipart messages,
4845 only the first displayable part is included.
4849 Display the message collected so far,
4850 prefaced by the message header fields
4851 and followed by the attachment list, if any.
4855 Abort the message being sent,
4856 copying it to the file specified by the
4863 .It Ic ~R Ar filename
4864 Read the named file into the message, indented by
4868 .It Ic ~r Ar filename
4869 Read the named file into the message.
4873 Cause the named string to become the current subject field.
4876 .It Ic ~t Ar name ...
4877 Add the given name(s) to the direct recipient list.
4880 .It Ic ~U Ar messages
4881 Read in the given / current message(s) excluding all headers, indented by
4885 .It Ic ~u Ar messages
4886 Read in the given / current message(s), excluding all headers.
4890 Invoke an alternate editor (defined by the
4892 option) on the message collected so far.
4893 Usually, the alternate editor will be a screen editor.
4894 After the editor is quit,
4895 the user may resume appending text to the end of the message.
4898 .It Ic ~w Ar filename
4899 Write the message onto the named file.
4901 the message is appended to it.
4907 except that the message is not saved at all.
4910 .It Ic ~| Ar command
4911 Pipe the message through the specified filter command.
4912 If the command gives no output or terminates abnormally,
4913 retain the original text of the message.
4916 is often used as a rejustifying filter.
4921 .\" .Sh INTERNAL VARIABLES {{{
4922 .Sh "INTERNAL VARIABLES"
4924 Internal \*(UA variables are controlled via the
4928 commands; prefixing a variable name with the string
4932 has the same effect as using
4938 Creation or editing of variables can be performed in the
4943 will give more insight on the given variable(s), and
4945 when called without arguments, will show a listing of all variables.
4946 Variables are also implicitly inherited from the program
4948 and can be set explicitly via the command line option
4952 Two different kind of variables exist.
4953 There are boolean variables, which can only be in one of the two states
4957 and value variables with a(n optional) string value.
4958 For the latter proper quoting is necessary upon assignment time:
4959 To embed whitespace (space and tabulator) in a value it either needs to
4960 be escaped with a backslash character, or the entire value must be
4961 enclosed in (double or single) quotation marks;
4962 To use quotation marks identical to those used to enclose the value,
4963 escape them with a backslash character.
4964 The backslash character has no special meaning except in these cases.
4966 .Bd -literal -offset indent
4967 set one=val\e 1 two="val 2" \e
4968 three='val "3"' four='val \e'4\e''
4969 varshow one two three four
4970 unset one two three four
4974 Dependent upon the actual option the string values will be interpreted
4975 as numbers, colour names, normal text etc., but there also exists
4976 a special kind of string value, the
4977 .Dq boolean string ,
4978 which must either be a decimal integer (in which case
4982 and any other value is true) or any of the (case-insensitive) strings
4987 for a false boolean and
4992 for a true boolean; a special kind of boolean string is the
4994 which is a boolean string that can optionally be prefixed with the
4995 (case-insensitive) term
4999 which causes prompting of the user in interactive mode, with the given
5000 boolean as the default value.
5002 .\" .Ss "Initial settings" {{{
5003 .\" (Keep in SYNC: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
5004 .Ss "Initial Settings"
5006 The standard POSIX 2008/Cor 1-2013 mandates the following initial
5012 .Pf no Va autoprint ,
5026 .Pf no Va ignoreeof ,
5028 .Pf no Va keepsave ,
5030 .Pf no Va outfolder ,
5035 (note that \*(UA deviates from the standard by using
5039 special prompt escape results in
5047 .Pf no Va sendwait ,
5056 Notes: \*(UA doesn't support the
5058 variable \(en use command line options or
5059 .Va sendmail-arguments
5060 to pass options through to a MTA.
5061 And the default global
5063 file (which is loaded unless the
5065 command line flag has been used or the
5066 .Ev NAIL_NO_SYSTEM_RC
5067 environment variable is set) bends those initial settings a bit, e.g.,
5068 it sets the variables
5073 to name a few, calls
5075 etc., and should thus be taken into account.
5078 .\" .Ss "Variables" {{{
5081 .Bl -tag -width ".It Va _utoprin_"
5083 .It Va add-file-recipients
5084 \*(BO When file or pipe recipients have been specified,
5085 mention them in the corresponding address fields of the message instead
5086 of silently stripping them from their recipient list.
5087 By default such addressees are not mentioned.
5089 .Mx Va agent-shell-lookup
5090 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5092 \*(IN\*(OP Account passwords can be fetched via an external agent
5093 program in order to permit encrypted password storage \(en see
5094 .Sx "On URL syntax and credential lookup"
5095 for more on credential lookup.
5096 If this is set then the content is interpreted as a shell command the
5097 output of which (with newline characters removed) is treated as the
5098 account password shall the command succeed (and have produced non-empty
5099 non-newline output); e.g., via
5101 .Bd -literal -offset indent
5102 $ echo PASSWORD > .pass
5104 $ eval `gpg-agent --daemon \e
5105 --pinentry-program=/usr/bin/pinentry-curses \e
5106 --max-cache-ttl 99999 --default-cache-ttl 99999`
5107 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5111 A couple of environment variables will be set for the agent:
5113 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5115 The temporary directory that \*(UA uses.
5116 Usually identical to
5118 but guaranteed to be set and usable by child processes;
5119 to ensure the latter condition for
5125 for which the password is looked up.
5126 .It Ev NAIL_USER_ENC
5127 The URL percent-encoded variant of
5130 The plain machine hostname of the user account.
5131 .It Ev NAIL_HOST_PORT
5134 (hostname possibly including port) of the user account.
5139 \*(BO Causes only the local part to be evaluated
5140 when comparing addresses.
5144 \*(BO Causes messages saved in
5146 to be appended to the end rather than prepended.
5147 This should always be set.
5151 \*(BO Causes \*(UA to prompt for the subject of each message sent.
5152 If the user responds with simply a newline,
5153 no subject field will be sent.
5157 \*(BO Causes the prompts for
5161 lists to appear after the message has been edited.
5165 \*(BO If set, \*(UA asks for files to attach at the end of each message,
5166 shall the list be found empty at that time.
5167 An empty line finalizes the list.
5171 \*(BO Causes the user to be prompted for carbon copy recipients
5172 (at the end of each message if
5176 are set) shall the list be found empty (at that time).
5177 An empty line finalizes the list.
5181 \*(BO Causes the user to be prompted for blind carbon copy
5182 recipients (at the end of each message if
5186 are set) shall the list be found empty (at that time).
5187 An empty line finalizes the list.
5191 \*(BO\*(OP Causes the user to be prompted if the message is to be
5192 signed at the end of each message.
5195 variable is ignored when this variable is set.
5199 \*(BO Alternative name for
5206 .It Va attachment-ask-content-description , \
5207 attachment-ask-content-disposition , \
5208 attachment-ask-content-id , \
5209 attachment-ask-content-type
5210 \*(BO If set then the user will be prompted for some attachment
5211 information when editing the attachment list.
5212 It is advisable to not use these but for the first of the variables;
5213 even for that it has to be noted that the data is used
5219 A sequence of characters to display in the
5223 as shown in the display of
5225 each for one type of messages (see
5226 .Sx "Message states" ) ,
5227 with the default being
5230 .Ql NU\ \ *HMFAT+\-$~
5233 variable is set, in the following order:
5235 .Bl -tag -compact -offset indent -width ".It Ql _"
5257 start of a collapsed thread.
5259 an uncollapsed thread (TODO ignored for now).
5263 classified as possible spam.
5269 Specifies a list of recipients to which a blind carbon copy of each
5270 outgoing message will be sent automatically.
5274 Specifies a list of recipients to which a carbon copy of each outgoing
5275 message will be sent automatically.
5279 \*(BO Causes threads to be collapsed automatically when threaded mode
5286 \*(BO Causes the delete command to behave like
5288 thus, after deleting a message the next one will be typed automatically.
5292 \*(BO\*(OB Causes threaded mode (see the
5294 command) to be entered automatically when a folder is opened.
5296 .Ql autosort=thread .
5300 Causes sorted mode (see the
5302 command) to be entered automatically with the value of this option as
5303 sorting method when a folder is opened, e.g.,
5304 .Ql set autosort=thread .
5308 \*(BO Enables the substitution of
5310 by the contents of the last command line in shell escapes.
5313 .It Va batch-exit-on-error
5314 \*(BO If the batch mode has been enabled via the
5316 command line option, then this variable will be consulted whenever \*(UA
5317 completes one operation (returns to the command prompt); if it is set
5318 then \*(UA will terminate if the last operation generated an error.
5322 \*(BO Causes automatic display of a header summary after executing a
5328 \*(BO Sets some cosmetical features to traditional BSD style;
5329 has the same affect as setting
5331 and all other variables prefixed with
5333 it also changes the meaning of the \*(UA specific
5336 escape sequence and changes behaviour of
5338 (which doesn't exist in BSD).
5342 \*(BO Changes the letters shown in the first column of a header
5343 summary to traditional BSD style.
5347 \*(BO Changes the display of columns in a header summary to traditional
5352 \*(BO Changes some informational messages to traditional BSD style.
5358 field to appear immediately after the
5360 field in message headers and with the
5362 .Sx "TILDE ESCAPES" .
5366 \*(BO Changes the output format of the
5368 command to traditional BSD style.
5372 The value that should appear in the
5376 MIME header fields when no character set conversion of the message data
5378 This defaults to US-ASCII, and the chosen character set should be
5379 US-ASCII compatible.
5383 \*(OP The default 8-bit character set that is used as an implicit last
5384 member of the variable
5386 This defaults to UTF-8.
5387 If no character set conversion capabilities are available in \*(UA then
5388 the only supported character set is
5390 Refer to the section
5391 .Sx "Character sets"
5392 for the complete picture of character set conversion in \*(UA.
5395 .It Va charset-unknown-8bit
5396 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5398 the content of a mail message by using a character set with the name
5400 Because of the unclassified nature of this character set \*(UA will not
5401 be capable to convert this character set to any other character set.
5402 If this variable is set any message part which uses the character set
5404 is assumed to really be in the character set given in the value,
5405 otherwise the (final) value of
5407 is used for this purpose.
5409 This variable will also be taken into account if a MIME type (see
5410 .Sx "The mime.types files" )
5411 of a MIME message part that uses the
5413 character set is forcefully treated as text.
5417 The default value for the
5422 .It Va colour-disable
5423 \*(BO\*(OP Forcefully disable usage of colours.
5424 Also see the section
5425 .Sx "Coloured display" .
5429 \*(BO\*(OP Wether colour shall be used for output that is paged through
5431 Note that pagers may need special flags, e.g.,
5439 in order to support colours; therefore \*(UA will inspect the variable
5441 \(en if that starts with the string
5443 a non-existing environment variable
5450 will optionally be set to
5452 Also see the section
5453 .Sx "Coloured display"
5458 In a(n interactive) terminal session, then if this valued option is set
5459 it'll be used as a threshold to determine how many lines the given
5460 output has to span before it will be displayed via the configured
5464 can be forced by setting this to the value
5466 setting it without a value will deduce the current height of the
5467 terminal screen to compute the treshold (see
5475 \*(OB A variable counterpart of the
5477 command (see there for documentation), interpreted as a comma-separated
5478 list of custom headers to be injected, to include commas in the header
5479 bodies escape them with backslash, e.g.:
5481 .Dl set customhdr="Hdr1: Body1-1\e, Body1-2, Hdr2: Body2"
5487 the message date, if any is to be displayed according to the format of
5489 is by default taken from the
5491 line of the message.
5492 If this variable is set the date as given in the
5494 header field is used instead, converted to local time.
5495 To control the display format of the date assign a valid
5500 format should not be used, because \*(UA doesn't take embedded newlines
5501 into account when calculating how many lines fit onto the screen.)
5503 .Va datefield-markout-older .
5506 .It Va datefield-markout-older
5507 This option, when set in addition to
5511 messages (concept is rather comparable to the
5513 option of the POSIX utility
5515 The content interpretation is identical to
5520 \*(BO Enables debug messages and obsoletion warnings, disables the
5521 actual delivery of messages and also implies
5527 .It Va disposition-notification-send
5529 .Ql Disposition-Notification-To:
5530 header (RFC 3798) with the message.
5534 .\" TODO .It Va disposition-notification-send-HOST
5536 .\".Va disposition-notification-send
5537 .\" for SMTP accounts on a specific host.
5538 .\" TODO .It Va disposition-notification-send-USER@HOST
5540 .\".Va disposition-notification-send
5541 .\"for a specific account.
5545 \*(BO When dot is set, a period
5547 on a line by itself during message input in (interactive) compose mode
5548 will be treated as end-of-message (in addition to the normal end-of-file
5557 .It Va dotlock-ignore-error
5558 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5559 mailboxes (see the command
5561 will be protected with so-called dotlock files\(emthe traditional mail
5562 spool file locking method\(emin addition to system file locking.
5563 Because \*(UA ships with a privilege-separated dotlock creation program
5564 that should always be able to create such a dotlock file there is no
5565 good reason to ignore dotlock file creation errors, and thus these are
5566 fatal unless this variable is set.
5570 \*(BO If this variable is set then the editor is started automatically
5571 when a message is composed in interactive mode, as if the
5577 variable is implied for this automatically spawned editor session.
5581 \*(BO When a message is edited while being composed,
5582 its header is included in the editable text.
5592 fields are accepted within the header, other fields are ignored.
5596 \*(BO When entering interactive mode \*(UA normally writes
5597 .Dq \&No mail for user
5598 and exits immediately if a mailbox is empty or doesn't exist.
5599 If this option is set \*(UA starts even with an empty or nonexistent
5600 mailbox (the latter behaviour furtherly depends upon
5606 Suggestion for the MIME encoding to use in outgoing text messages
5608 Valid values are the default
5609 .Ql quoted-printable ,
5614 may cause problems when transferring mail messages over channels that
5615 are not ESMTP (RFC 1869) compliant.
5616 If there is no need to encode a message,
5618 transfer mode is always used regardless of this variable.
5619 Binary data is always encoded as
5624 If defined, the first character of this option
5625 gives the character to use in place of
5628 .Sx "TILDE ESCAPES" .
5632 If not set then file and command pipeline targets are not allowed,
5633 and any such address will be filtered out, giving a warning message.
5634 If set without a value then all possible recipient address
5635 specifications will be accepted \(en see the section
5636 .Sx "On sending mail, and non-interactive mode"
5638 To accept them, but only in interactive mode, or when tilde commands
5639 were enabled explicitly by using one of the command line options
5643 set this to the (case-insensitive) value
5645 (note right now this is actually like setting
5646 .Ql restrict,-all,+name,+addr ) .
5648 In fact the value is interpreted as a comma-separated list of values.
5651 then the existence of disallowed specifications is treated as a hard
5652 send error instead of only filtering them out.
5653 The remaining values specify wether a specific type of recipient
5654 address specification is allowed (optionally indicated by a plus sign
5656 prefix) or disallowed (prefixed with a hyphen
5660 addresses all possible address specifications,
5664 command pipeline targets,
5666 plain user names and (MTA) aliases (\*(OB
5668 may be used as an alternative syntax to
5673 These kind of values are interpreted in the given order, so that
5674 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5675 will cause hard errors for any non-network address recipient address
5676 unless \*(UA is in interactive mode or has been started with the
5680 command line option; in the latter case(s) any address may be used, then.
5684 Unless this variable is set additional mail-transfer-agent (MTA)
5685 arguments from the command line, as can be given after a
5687 separator, are ignored due to safety reasons.
5688 However, if set to the special (case-insensitive) value
5690 then the presence of additional MTA arguments is treated as a hard
5691 error that causes \*(UA to exit with failure status.
5692 A lesser strict variant is the otherwise identical
5694 which does accept such arguments in interactive mode, or if tilde
5695 commands were enabled explicitly by using one of the command line options
5702 \*(RO Information on the features compiled into \*(UA \(en the content
5703 of this variable is identical to the output of the command
5708 \*(BO This option reverses the meanings of a set of reply commands,
5709 turning the lowercase variants, which by default address all recipients
5710 included in the header of a message
5711 .Pf ( Ic reply , respond , followup )
5712 into the uppercase variants, which by default address the sender only
5713 .Pf ( Ic Reply , Respond , Followup )
5716 .Ic replysender , respondsender , followupsender
5718 .Ic replyall , respondall , followupall
5719 are not affected by the current setting of
5724 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5725 It is possible to install file hooks which will be used by the
5727 command in order to be able to transparently handle (through an
5728 intermediate temporary file) files with specific
5730 s: the variable values can include shell snippets and are expected to
5731 write data to standard output / read data from standard input,
5733 \*(ID The variables may not be changed while there is a mailbox
5735 .Bd -literal -offset indent
5736 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5737 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5738 record=+null-sent.xy
5743 The name of the directory to use for storing folders of messages.
5744 All folder names that begin with
5746 refer to files below it.
5747 The same special conventions as documented for the
5749 command may be used when specifying a new value for
5751 but be aware that the expansion is fully performed immediately.
5755 This variable can be set to the name of a
5757 macro which will be called whenever a
5760 The macro will also be invoked when new mail arrives,
5761 but message lists for commands executed from the macro
5762 only include newly arrived messages then.
5764 are activated by default in a folder hook, causing the covered settings
5765 to be reverted once the folder is left again.
5768 Macro behaviour, including option localization, will change in v15.
5769 Please be aware of that and possibly embed a version check in a resource
5773 .It Va folder-hook-FOLDER
5778 Unlike other folder specifications, the fully expanded name of a folder,
5779 without metacharacters, is used to avoid ambiguities.
5780 However, if the mailbox resides under
5784 specification is tried in addition, e.g., if
5788 (and thus relative to the user's home directory) then
5789 .Pa /home/usr1/mail/sent
5791 .Ql folder-hook-/home/usr1/mail/sent
5792 first, but then followed by
5793 .Ql folder-hook-+sent .
5797 \*(BO Controls wether a
5798 .Ql Mail-Followup-To:
5799 header is generated when sending messages to known mailing lists.
5801 .Va followup-to-honour
5803 .Ic mlist , mlsubscribe , reply
5808 .It Va followup-to-honour
5810 .Ql Mail-Followup-To:
5811 header is honoured when group-replying to a message via
5815 This is a quadoption; if set without a value it defaults to
5825 .It Va forward-as-attachment
5826 \*(BO Original messages are normally sent as inline text with the
5829 and only the first part of a multipart message is included.
5830 With this option messages are sent as unmodified MIME
5832 attachments with all of their parts included.
5836 The address (or a list of addresses) to put into the
5838 field of the message header, quoting RFC 5322:
5839 the author(s) of the message, that is, the mailbox(es) of the person(s)
5840 or system(s) responsible for the writing of the message.
5841 If replying to messages these addresses are handled as if they were in
5845 If the machine's hostname is not valid at the Internet (for example at
5846 a dialup machine) then either this variable or
5851 adds even more fine-tuning capabilities),
5855 contains more than one address,
5858 variable is required (according to the standard RFC 5322).
5862 \*(BO When replying to or forwarding a message \*(UA normally removes
5863 the comment and name parts of email addresses.
5864 If this variable is set such stripping is not performed,
5865 and comments, names etc. are retained.
5869 The string to put before the text of a message with the
5873 .Va forward-as-attachment
5876 .Dq -------- Original Message --------
5877 if unset; No heading is put if it is set to the empty string.
5881 \*(BO Causes the header summary to be written at startup and after
5882 commands that affect the number of messages or the order of messages in
5883 the current folder; enabled by default.
5884 The command line option
5892 A format string to use for the summary of
5894 similar to the ones used for
5897 Format specifiers in the given string start with a percent character
5899 and may be followed by an optional decimal number indicating the field
5900 width \(em if that is negative, the field is to be left-aligned.
5901 Valid format specifiers are:
5904 .Bl -tag -compact -offset indent -width "_%%_"
5906 A plain percent character.
5909 a space character but for the current message
5911 for which it expands to
5915 a space character but for the current message
5917 for which it expands to
5920 \*(OP The spam score of the message, as has been classified via the
5923 Shows only a replacement character if there is no spam support.
5925 Message attribute character (status flag); the actual content can be
5929 The date when the message was received, or the date found in the
5933 variable is set (optionally to a date display format string).
5935 The indenting level in threaded mode.
5937 The address of the message sender.
5939 The message thread tree structure.
5940 (Note that this format doesn't support a field width.)
5942 The number of lines of the message, if available.
5946 The number of octets (bytes) in the message, if available.
5948 Message subject (if any).
5950 Message subject (if any) in double quotes.
5952 Message recipient flags: is the addressee of the message a known or
5953 subscribed mailing list \(en see
5958 The position in threaded/sorted order.
5962 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
5964 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
5975 .It Va headline-bidi
5976 Bidirectional text requires special treatment when displaying headers,
5977 because numbers (in dates or for file sizes etc.) will not affect the
5978 current text direction, in effect resulting in ugly line layouts when
5979 arabic or other right-to-left text is to be displayed.
5980 On the other hand only a minority of terminals is capable to correctly
5981 handle direction changes, so that user interaction is necessary for
5983 Note that extended host system support is required nonetheless, e.g.,
5984 detection of the terminal character set is one precondition;
5985 and this feature only works in an Unicode (i.e., UTF-8) locale.
5987 In general setting this variable will cause \*(UA to encapsulate text
5988 fields that may occur when displaying
5990 (and some other fields, like dynamic expansions in
5992 with special Unicode control sequences;
5993 it is possible to fine-tune the terminal support level by assigning
5995 no value (or any value other than
6000 will make \*(UA assume that the terminal is capable to properly deal
6001 with Unicode version 6.3, in which case text is embedded in a pair of
6002 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6004 In addition no space on the line is reserved for these characters.
6006 Weaker support is chosen by using the value
6008 (Unicode 6.3, but reserve the room of two spaces for writing the control
6009 sequences onto the line).
6014 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6015 again reserves room for two spaces in addition.
6019 \*(OP If a line editor is available then this can be set to
6020 name the (expandable) path of the location of a permanent history file.
6023 .It Va history-gabby
6024 \*(BO\*(OP Add more entries to the history as is normally done.
6027 .It Va history-gabby-persist
6028 \*(BO\*(OP \*(UA's own MLE will not save the additional
6030 entries in persistent storage unless this variable is set.
6031 On the other hand it will not loose the knowledge of wether a persistent
6032 entry was gabby or not.
6038 \*(OP If a line editor is available this value restricts the
6039 amount of history entries that are saved into a set and valid
6041 A value of less than 0 disables this feature;
6042 note that loading and incorporation of
6044 upon program startup can also be suppressed by doing this.
6045 An unset or invalid value, or 0, causes a default value to be used.
6046 Dependent on the available line editor this will also define the
6047 number of history entries in memory;
6048 it is also editor-specific wether runtime updates of this value will be
6053 \*(BO This option is used to hold messages in the system mailbox,
6054 and it is set by default.
6058 Use this string as hostname when expanding local addresses instead of
6059 the value obtained from
6070 transport is not used then it is normally the responsibility of the MTA
6071 to create these fields, \*(IN in conjunction with
6075 also influences the results;
6076 you should produce some test messages with the desired combination of
6085 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
6086 names according to the rules of IDNA (internationalized domain names
6088 Since the IDNA code assumes that domain names are specified with the
6090 character set, an UTF-8 locale charset is required to represent all
6091 possible international domain names (before conversion, that is).
6095 \*(BO Ignore interrupt signals from the terminal while entering
6096 messages; instead echo them as
6098 characters and discard the current line.
6102 \*(BO Ignore end-of-file conditions
6103 .Pf ( Ql control-D )
6104 in compose mode on message input and in interactive command input.
6105 If set an interactive command input session can only be left by
6106 explicitly using one of the commands
6110 and message input in compose mode can only be terminated by entering
6113 on a line by itself or by using the
6115 .Sx "TILDE ESCAPES" ;
6117 overrides a setting of
6129 option for indenting messages,
6130 in place of the normal tabulator character
6132 which is the default.
6133 Be sure to quote the value if it contains spaces or tabs.
6137 \*(BO If set, an empty mailbox file is not removed.
6138 This may improve the interoperability with other mail user agents
6139 when using a common folder directory, and prevents malicious users
6140 from creating fake mailboxes in a world-writable spool directory.
6141 Note this only applies to local regular (MBOX) files, other mailbox
6142 types will never be removed.
6145 .It Va keep-content-length
6146 \*(BO When (editing messages and) writing
6148 mailbox files \*(UA can be told to keep the
6152 header fields that some MUAs generate by setting this variable.
6153 Since \*(UA does neither use nor update these non-standardized header
6154 fields (which in itself shows one of their conceptual problems),
6155 stripping them should increase interoperability in between MUAs that
6156 work with with same mailbox files.
6157 Note that, if this is not set but
6158 .Va writebackedited ,
6159 as below, is, a possibly performed automatic stripping of these header
6160 fields already marks the message as being modified.
6164 \*(BO When a message is saved it is usually discarded from the
6165 originating folder when \*(UA is quit.
6166 Setting this option causes all saved message to be retained.
6169 .It Va line-editor-disable
6170 \*(BO Turn off any enhanced line editing capabilities (see
6171 .Sx "On terminal control and line editor"
6176 \*(BO When a message is replied to and this variable is set,
6177 it is marked as having been answered.
6178 This mark has no technical meaning in the mail system;
6179 it just causes messages to be marked in the header summary,
6180 and makes them specially addressable.
6184 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6186 Messages which are fetched over the network or from within already
6187 existing Maildir (or any non-MBOX) mailboxes may require so-called
6189 quoting (insertion of additional
6191 characters to prevent line content misinterpretation) to be applied in
6192 order to be storable in MBOX mailboxes, however, dependent on the
6193 circumspection of the message producer.
6194 (E.g., \*(UA itself will, when newly generating messages, choose a
6195 .Pf Content-Transfer- Va encoding
6196 that prevents the necessity for such quoting \(en a necessary
6197 precondition to ensure message checksums won't change.)
6199 By default \*(UA will perform this
6201 quoting in a way that results in a MBOX file that is compatible with
6202 the POSIX MBOX layout, which means that, in order not to exceed the
6203 capabilities of simple applications, many more
6205 lines get quoted (thus modified) than necessary according to RFC 4155.
6206 Set this option to instead generate MBOX files which comply to RFC 4155.
6210 \*(BO Internal development variable.
6213 .It Va message-id-disable
6214 \*(BO By setting this option the generation of
6216 can be completely suppressed, effectively leaving this task up to the
6217 mail-transfer-agent (MTA) or the SMTP server.
6218 (According to RFC 5321 your SMTP server is not required to add this
6219 field by itself, so you should ensure that it accepts messages without a
6223 .It Va message-inject-head
6224 A string to put at the beginning of each new message.
6225 The escape sequences tabulator
6232 .It Va message-inject-tail
6233 A string to put at the end of each new message.
6234 The escape sequences tabulator
6242 \*(BO Usually, when an
6244 expansion contains the sender, the sender is removed from the expansion.
6245 Setting this option suppresses these removals.
6250 option to be passed to mail-transfer-agents (MTAs);
6251 though most of the modern MTAs don't (no longer) document this flag, no
6252 MTA is known which doesn't support it (for historical compatibility).
6255 .It Va mime-allow-text-controls
6256 \*(BO When sending messages, each part of the message is MIME-inspected
6257 in order to classify the
6260 .Ql Content-Transfer-Encoding:
6263 that is required to send this part over mail transport, i.e.,
6264 a computation rather similar to what the
6266 command produces when used with the
6270 This classification however treats text files which are encoded in
6271 UTF-16 (seen for HTML files) and similar character sets as binary
6272 octet-streams, forcefully changing any
6277 .Ql application/octet-stream :
6278 If that actually happens a yet unset charset MIME parameter is set to
6280 effectively making it impossible for the receiving MUA to automatically
6281 interpret the contents of the part.
6283 If this option is set, and the data was unambiguously identified as text
6284 data at first glance (by a
6288 file extension), then the original
6290 will not be overwritten.
6293 .It Va mime-alternative-favour-rich
6294 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6295 HTML) will be preferred in favour of included plain text versions when
6296 displaying messages, provided that a handler exists which produces
6297 output that can be (re)integrated into \*(UA's normal visual display.
6298 (E.g., at the time of this writing some newsletters ship their full
6299 content only in the rich HTML part, whereas the plain text part only
6300 contains topic subjects.)
6303 .It Va mime-counter-evidence
6306 field is used to decide how to handle MIME parts.
6307 Some MUAs however don't use
6309 or a similar mechanism to correctly classify content, but simply specify
6310 .Ql application/octet-stream ,
6311 even for plain text attachments like
6313 If this variable is set then \*(UA will try to classify such MIME
6314 message parts on its own, if possible, for example via a possibly
6315 existent attachment filename.
6316 A non-empty value may also be given, in which case a number is expected,
6317 actually a carrier of bits.
6318 Creating the bit-carrying number is a simple addition:
6319 .Bd -literal -offset indent
6320 ? !echo Value should be set to $((2 + 4 + 8))
6321 Value should be set to 14
6324 .Bl -bullet -compact
6326 If bit two is set (2) then the detected
6328 content-type will be carried along with the message and be used for
6330 .Va pipe-TYPE/SUBTYPE
6331 is responsible for the MIME part, shall that question arise;
6332 when displaying such a MIME part the part-info will indicate the
6333 overridden content-type by showing a plus-sign
6336 If bit three is set (4) then the counter-evidence is always produced
6337 and a positive result will be used as the MIME type, even forcefully
6338 overriding the parts given MIME type.
6340 If bit four is set (8) then as a last resort the actual content of
6341 .Ql application/octet-stream
6342 parts will be inspected, so that data which looks like plain text can be
6347 .It Va mimetypes-load-control
6348 This option can be used to control which of the
6350 databases are loaded by \*(UA, as furtherly described in the section
6351 .Sx "The mime.types files" .
6354 is part of the option value, then the user's personal
6356 file will be loaded (if it exists); likewise the letter
6358 controls loading of the system wide
6359 .Pa /etc/mime.types ;
6360 directives found in the user file take precedence, letter matching is
6362 If this option is not set \*(UA will try to load both files.
6363 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6364 but they will be matched last.
6366 More sources can be specified by using a different syntax: if the
6367 value string contains an equals sign
6369 then it is instead parsed as a comma-separated list of the described
6372 pairs; the given filenames will be expanded and loaded, and their
6373 content may use the extended syntax that is described in the section
6374 .Sx "The mime.types files" .
6375 Directives found in such files always take precedence (are prepended to
6376 the MIME type cache).
6379 .It Va NAIL_EXTRA_RC
6380 The name of an optional startup file to be read last.
6381 This variable has an effect only if it is set in any of the
6382 .Sx "Resource files" ,
6383 it is not imported from the environment.
6384 Use this file for commands that are not understood by other POSIX
6389 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6390 \*(BO\*(IN\*(OP Used to control usage of the users
6392 file for lookup of account credentials, as documented in the section
6393 .Sx "On URL syntax and credential lookup"
6397 .Sx "The .netrc file"
6398 documents the file format.
6402 If this variable has the value
6404 newly created local folders will be in Maildir format.
6408 Checks for new mail in the current folder each time the prompt is shown.
6409 A Maildir folder must be re-scanned to determine if new mail has arrived.
6410 If this variable is set to the special value
6412 then a Maildir folder will not be rescanned completely, but only
6413 timestamp changes are detected.
6417 .It Va on-compose-enter , on-compose-leave
6418 \*(ID Macro hooks which will be executed before compose mode is
6419 entered, and after composing has been finished, respectively.
6420 Please note that this interface is very likely to change in v15, and
6421 should therefore possibly even be seen as experimental.
6423 are by default enabled for these hooks, causing any setting to be
6424 forgotten after the message has been sent.
6425 The following variables will be set temporarily during execution of the
6428 .Bl -tag -compact -width ".It Va compose_subject"
6431 .It Va compose-sender
6433 .It Va compose-to , compose-cc , compose-bcc
6434 The list of receiver addresses as a space-separated list.
6435 .It Va compose-subject
6441 \*(BO Causes the filename given in the
6444 and the sender-based filenames for the
6448 commands to be interpreted relative to the directory given in the
6450 variable rather than to the current directory,
6451 unless it is set to an absolute pathname.
6455 \*(BO If set, each message feed through the command given for
6457 is followed by a formfeed character
6461 .It Va password-USER@HOST , password-HOST , password
6462 \*(IN Variable chain that sets a password, which is used in case none has
6463 been given in the protocol and account-specific URL;
6464 as a last resort \*(UA will ask for a password on the user's terminal if
6465 the authentication method requires a password.
6466 Specifying passwords in a startup file is generally a security risk;
6467 the file should be readable by the invoking user only.
6469 .It Va password-USER@HOST
6470 \*(OU (see the chain above for \*(IN)
6471 Set the password for
6475 If no such variable is defined for a host,
6476 the user will be asked for a password on standard input.
6477 Specifying passwords in a startup file is generally a security risk;
6478 the file should be readable by the invoking user only.
6482 \*(BO Send messages to the
6484 command without performing MIME and character set conversions.
6488 .It Va pipe-TYPE/SUBTYPE
6489 When a MIME message part of type
6491 (case-insensitive) is displayed or quoted,
6492 its text is filtered through the value of this variable interpreted as
6496 forces interpretation of the message part as plain text, e.g.,
6497 .Ql set pipe-application/xml=@
6498 will henceforth display XML
6500 (The same could also be achieved by adding a MIME type marker with the
6503 And \*(OPally MIME type handlers may be defined via
6504 .Sx "The Mailcap files"
6505 \(em corresponding flag strings are shown in parenthesis below.)
6510 can in fact be used to adjust usage and behaviour of a following shell
6511 command specification by appending trigger characters to it, e.g., the
6512 following hypothetical command specification could be used:
6513 .Bd -literal -offset indent
6514 set pipe-X/Y="@*!++=@vim ${NAIL_FILENAME_TEMPORARY}"
6518 .Bl -tag -compact -width ".It Ql __"
6520 Simply by using the special
6522 prefix the MIME type (shell command) handler will only be invoked to
6523 display or convert the MIME part if the message is addressed directly
6524 and alone by itself.
6525 Use this trigger to disable this and always invoke the handler
6526 .Pf ( Cd x-mailx-always ) .
6529 If set the handler will not be invoked when a message is to be quoted,
6530 but only when it will be displayed
6531 .Pf ( Cd x-mailx-noquote ) .
6534 The command will be run asynchronously, i.e., without blocking \*(UA,
6535 which may be a handy way to display a, e.g., PDF file while also
6536 continuing to read the mail message
6537 .Pf ( Cd x-mailx-async ) .
6538 Asynchronous execution implies
6542 The command must be run on an interactive terminal, \*(UA will
6543 temporarily release the terminal to it
6544 .Pf ( Cd needsterminal ) .
6545 This flag is mutual exclusive with
6547 will only be used in interactive mode and implies
6551 Request creation of a zero-sized temporary file, the absolute pathname
6552 of which will be made accessable via the environment variable
6553 .Ev NAIL_FILENAME_TEMPORARY
6554 .Pf ( Cd x-mailx-tmpfile ) .
6555 If this trigger is given twice then the file will be unlinked
6556 automatically by \*(UA when the command loop is entered again at latest
6557 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6558 (Don't use this for asynchronous handlers.)
6561 Normally the MIME part content is passed to the handler via standard
6562 input; if this flag is set then the data will instead be written into
6563 .Ev NAIL_FILENAME_TEMPORARY
6564 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6565 the creation of which is implied; note however that in order to cause
6566 deletion of the temporary file you still have to use two plus signs
6571 To avoid ambiguities with normal shell command content you can use
6572 another at-sign to forcefully terminate interpretation of remaining
6574 (Any character not in this list will have the same effect.)
6578 Some information about the MIME part to be displayed is embedded into
6579 the environment of the shell command:
6582 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6585 The MIME content-type of the part, if known, the empty string otherwise.
6588 .It Ev NAIL_CONTENT_EVIDENCE
6590 .Va mime-counter-evidence
6591 includes the carry-around-bit (2), then this will be set to the detected
6592 MIME content-type; not only then identical to
6593 .Ev \&\&NAIL_CONTENT
6597 .It Ev NAIL_FILENAME
6598 The filename, if any is set, the empty string otherwise.
6601 .It Ev NAIL_FILENAME_GENERATED
6605 .It Ev NAIL_FILENAME_TEMPORARY
6606 If temporary file creation has been requested through the command prefix
6607 this variable will be set and contain the absolute pathname of the
6612 The temporary directory that \*(UA uses.
6613 Usually identical to
6615 but guaranteed to be set and usable by child processes;
6616 to ensure the latter condition for
6623 .It Va pipe-EXTENSION
6624 This is identical to
6625 .Va pipe-TYPE/SUBTYPE
6628 (normalized to lowercase using character mappings of the ASCII charset)
6629 names a file extension, e.g.,
6631 Handlers registered using this method take precedence.
6634 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6635 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6636 The only possible value as of now is
6638 which is thus the default.
6641 .Mx Va pop3-bulk-load
6642 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6643 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6644 the messages, and only requests the message bodies on user request.
6645 For the POP3 protocol this means that the message headers will be
6647 If this option is set then \*(UA will download only complete messages
6648 from the given POP3 server(s) instead.
6650 .Mx Va pop3-keepalive
6651 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6652 \*(OP POP3 servers close the connection after a period of inactivity;
6653 the standard requires this to be at least 10 minutes,
6654 but practical experience may vary.
6655 Setting this variable to a numeric value greater than
6659 command to be sent each value seconds if no other operation is performed.
6662 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6663 \*(BO\*(OP Unless this variable is set the
6665 authentication method will be used when connecting to a POP3 server that
6669 is that the password is not sent in clear text over the wire and that
6670 only a single packet is sent for the user/password tuple.
6672 .Va pop3-no-apop-HOST
6675 .Mx Va pop3-use-starttls
6676 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6677 \*(BO\*(OP Causes \*(UA to issue a
6679 command to make an unencrypted POP3 session SSL/TLS encrypted.
6680 This functionality is not supported by all servers,
6681 and is not used if the session is already encrypted by the POP3S method.
6683 .Va pop3-use-starttls-HOST
6687 .It Va print-alternatives
6688 \*(BO When a MIME message part of type
6689 .Ql multipart/alternative
6690 is displayed and it contains a subpart of type
6692 other parts are normally discarded.
6693 Setting this variable causes all subparts to be displayed,
6694 just as if the surrounding part was of type
6695 .Ql multipart/mixed .
6699 The string shown when a command is accepted.
6700 Prompting may be prevented by either setting this to the null string
6703 The same XSI escape sequences that are understood by the
6705 command may be used within
6708 In addition, the following \*(UA specific additional sequences are
6715 is set, in which case it expands to
6719 is the default value of
6722 which will expand to
6724 if the last command failed and to
6728 which will expand to the name of the currently active
6730 if any, and to the empty string otherwise, and
6732 which will expand to the name of the currently active mailbox.
6733 (Note that the prompt buffer is size-limited, excess is cut off.)
6739 to encapsulate the expansions of the
6743 escape sequences as necessary to correctly display bidirectional text,
6744 this is not true for the final string that makes up
6746 as such, i.e., real BIDI handling is not supported.
6750 \*(BO Suppresses the printing of the version when first invoked.
6754 If set, \*(UA starts a replying message with the original message
6755 prefixed by the value of the variable
6757 Normally, a heading consisting of
6758 .Dq Fromheaderfield wrote:
6759 is put before the quotation.
6764 variable, this heading is omitted.
6767 is assigned, the headers selected by the
6768 .Ic ignore Ns / Ns Ic retain
6769 commands are put above the message body,
6772 acts like an automatic
6778 is assigned, all headers are put above the message body and all MIME
6779 parts are included, making
6781 act like an automatic
6784 .Va quote-as-attachment .
6787 .It Va quote-as-attachment
6788 \*(BO Add the original message in its entirety as a
6790 MIME attachment when replying to a message.
6791 Note this works regardless of the setting of
6796 \*(OP Can be set in addition to
6798 Setting this turns on a more fancy quotation algorithm in that leading
6799 quotation characters are compressed and overlong lines are folded.
6801 can be set to either one or two (space separated) numeric values,
6802 which are interpreted as the maximum (goal) and the minimum line length,
6803 respectively, in a spirit rather equal to the
6805 program, but line-, not paragraph-based.
6806 If not set explicitly the minimum will reflect the goal algorithmically.
6807 The goal can't be smaller than the length of
6809 plus some additional pad.
6810 Necessary adjustments take place silently.
6813 .It Va recipients-in-cc
6814 \*(BO On group replies, specify only the sender of the original mail in
6816 and mention the other recipients in the secondary
6818 By default all recipients of the original mail will be addressed via
6823 If defined, gives the pathname of the folder used to record all outgoing
6825 If not defined, then outgoing mail is not saved.
6826 When saving to this folder fails the message is not sent,
6827 but instead saved to
6831 .It Va record-resent
6832 \*(BO If both this variable and the
6839 commands save messages to the
6841 folder as it is normally only done for newly composed messages.
6844 .It Va reply-in-same-charset
6845 \*(BO If this variable is set \*(UA first tries to use the same
6846 character set of the original message for replies.
6847 If this fails, the mechanism described in
6848 .Sx "Character sets"
6849 is evaluated as usual.
6852 .It Va reply_strings
6853 Can be set to a comma-separated list of (case-insensitive according to
6854 ASCII rules) strings which shall be recognized in addition to the
6857 reply message indicators \(en builtin are
6859 which is mandated by RFC 5322, as well as the german
6864 A list of addresses to put into the
6866 field of the message header.
6867 Members of this list are handled as if they were in the
6872 .It Va reply-to-honour
6875 header is honoured when replying to a message via
6879 This is a quadoption; if set without a value it defaults to
6883 .It Va rfc822-body-from_
6884 \*(BO This variable can be used to force displaying a so-called
6886 line for messages that are embedded into an envelope mail via the
6888 MIME mechanism, for more visual convenience.
6892 \*(BO Enable saving of (partial) messages in
6894 upon interrupt or delivery error.
6898 When \*(UA initially displays the message headers it determines the
6899 number to display by looking at the speed of the terminal.
6900 The faster the terminal, the more will be shown.
6901 This option specifies the number to use and overrides the calculation.
6902 This number is also used for scrolling with the
6905 Overall screen dimensions and pager usage is influenced by the
6906 environment variables
6914 .It Va searchheaders
6915 \*(BO Expand message-list specifiers in the form
6917 to all messages containing the substring
6921 The string search is case insensitive.
6925 \*(OP A comma-separated list of character set names that can be used in
6926 outgoing internet mail.
6927 The value of the variable
6929 is automatically appended to this list of character-sets.
6930 If no character set conversion capabilities are compiled into \*(UA then
6931 the only supported charset is
6934 .Va sendcharsets-else-ttycharset
6935 and refer to the section
6936 .Sx "Character sets"
6937 for the complete picture of character set conversion in \*(UA.
6940 .It Va sendcharsets-else-ttycharset
6941 \*(BO\*(OP If this variable is set, but
6943 is not, then \*(UA acts as if
6945 had been set to the value of the variable
6947 In effect this combination passes through the message data in the
6948 character set of the current locale (given that
6950 hasn't been set manually), i.e., without converting it to the
6952 fallback character set.
6953 Thus, mail message text will be in ISO-8859-1 encoding when send from
6954 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
6956 If no character set conversion capabilities are available in \*(UA then
6957 the only supported character set is
6962 An address that is put into the
6964 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6965 responsible for the actual transmission of the message.
6966 This field should normally not be used unless the
6968 field contains more than one address, on which case it is required.
6971 address is handled as if it were in the
6977 To use an alternate mail transport agent (MTA),
6978 set this option to the full pathname of the program to use.
6979 It may be necessary to set
6980 .Va sendmail-progname
6983 The MTA will be passed command line arguments from several possible
6984 sources: from the variable
6985 .Va sendmail-arguments
6986 if set, from the command line if given and the variable
6989 Argument processing of the MTA will be terminated with a
6993 The otherwise occurring implicit usage of the following MTA command line
6994 arguments can be disabled by setting the boolean option
6995 .Va sendmail-no-default-arguments
6996 (which will also disable passing
7000 (for not treating a line with only a dot
7002 character as the end of input),
7010 option is set); in conjunction with the
7012 command line option \*(UA will also pass
7018 .It Va sendmail-arguments
7019 Arguments to pass through to the Mail-Transfer-Agent can be given via
7021 The content of this variable will be split up in a vector of arguments
7022 which will be joined onto other possible MTA options:
7024 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7027 .It Va sendmail-no-default-arguments
7028 \*(BO Unless this option is set \*(UA will pass some well known
7029 standard command line options to the defined
7031 program, see there for more.
7034 .It Va sendmail-progname
7035 Many systems use a so-called
7037 environment to ensure compatibility with
7039 This works by inspecting the name that was used to invoke the mail
7041 If this variable is set then the mailwrapper (the program that is
7042 actually executed when calling
7044 will treat its contents as that name.
7050 \*(BO When sending a message wait until the MTA (including the builtin
7051 SMTP one) exits before accepting further commands.
7053 with this variable set errors reported by the MTA will be recognizable!
7054 If the MTA returns a non-zero exit status,
7055 the exit status of \*(ua will also be non-zero.
7059 \*(BO Setting this option causes \*(UA to start at the last message
7060 instead of the first one when opening a mail folder.
7064 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7065 address in the header field summary and in message specifications.
7069 \*(BO Causes the recipient of the message to be shown in the header
7070 summary if the message was sent by the user.
7074 A string for use with the
7080 A string for use with the
7086 Must correspond to the name of a readable file if set.
7087 The file's content is then appended to each singlepart message
7088 and to the first part of each multipart message.
7089 Be warned that there is no possibility to edit the signature for an
7093 .It Va skipemptybody
7094 \*(BO If an outgoing message does not contain any text in its first or
7095 only message part, do not send it but discard it silently (see also the
7101 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7102 Enhanced Mail) format for verification of S/MIME signed messages.
7105 .It Va smime-ca-file
7106 \*(OP Specifies a file with CA certificates in PEM format for
7107 verification of S/MIME signed messages.
7110 .It Va smime-cipher-USER@HOST , smime-cipher
7111 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7112 messages (for the specified account).
7113 RFC 5751 mandates a default of
7116 Possible values are (case-insensitive and) in decreasing cipher strength:
7124 (DES EDE3 CBC, 168 bits; default if
7126 isn't available) and
7130 The actually available cipher algorithms depend on the cryptographic
7131 library that \*(UA uses.
7132 \*(OP Support for more cipher algorithms may be available through
7133 dynamic loading via, e.g.,
7134 .Xr EVP_get_cipherbyname 3
7135 (OpenSSL) if \*(UA has been compiled to support this.
7138 .It Va smime-crl-dir
7139 \*(OP Specifies a directory that contains files with CRLs in PEM format
7140 to use when verifying S/MIME messages.
7143 .It Va smime-crl-file
7144 \*(OP Specifies a file that contains a CRL in PEM format to use when
7145 verifying S/MIME messages.
7148 .It Va smime-encrypt-USER@HOST
7149 \*(OP If this variable is set, messages send to the given receiver are
7150 encrypted before sending.
7151 The value of the variable must be set to the name of a file that
7152 contains a certificate in PEM format.
7154 If a message is sent to multiple recipients,
7155 each of them for whom a corresponding variable is set will receive an
7156 individually encrypted message;
7157 other recipients will continue to receive the message in plain text
7159 .Va smime-force-encryption
7161 It is recommended to sign encrypted messages, i.e., to also set the
7166 .It Va smime-force-encryption
7167 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7170 .It Va smime-no-default-ca
7171 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7176 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7177 and include the user's certificate as a MIME attachment.
7178 Signing a message enables a recipient to verify that the sender used
7179 a valid certificate,
7180 that the email addresses in the certificate match those in the message
7181 header and that the message content has not been altered.
7182 It does not change the message text,
7183 and people will be able to read the message as usual.
7185 .Va smime-sign-cert , smime-sign-include-certs
7187 .Va smime-sign-message-digest .
7189 .Mx Va smime-sign-cert
7190 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7191 \*(OP Points to a file in PEM format.
7192 For the purpose of signing and decryption this file needs to contain the
7193 user's private key as well as his certificate.
7197 is always derived from the value of
7199 (or, if that contains multiple addresses,
7201 For the purpose of encryption the recipient's public encryption key
7202 (certificate) is expected; the command
7204 can be used to save certificates of signed messages (the section
7205 .Sx "Signed and encrypted messages with S/MIME"
7206 gives some details).
7207 This mode of operation is usually driven by the specialized form.
7209 When decrypting messages the account is derived from the recipient
7214 of the message, which are searched for addresses for which such
7216 \*(UA always uses the first address that matches,
7217 so if the same message is sent to more than one of the user's addresses
7218 using different encryption keys, decryption might fail.
7220 .Mx Va smime-sign-include-certs
7221 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7222 \*(OP If used, this is supposed to a consist of a comma-separated list
7223 of files, each of which containing a single certificate in PEM format to
7224 be included in the S/MIME message in addition to the
7227 This is most useful for long certificate chains if it is desired to aid
7228 the receiving party's verification process.
7229 Note that top level certificates may also be included in the chain but
7230 don't play a role for verification.
7232 .Va smime-sign-cert .
7233 Remember that for this
7235 refers to the variable
7237 (or, if that contains multiple addresses,
7240 .Mx Va smime-sign-message-digest
7241 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7242 \*(OP Specifies the message digest to use when signing S/MIME messages.
7243 RFC 5751 mandates a default of
7245 Possible values are (case-insensitive and) in decreasing cipher strength:
7253 The actually available message digest algorithms depend on the
7254 cryptographic library that \*(UA uses.
7255 \*(OP Support for more message digest algorithms may be available
7256 through dynamic loading via, e.g.,
7257 .Xr EVP_get_digestbyname 3
7258 (OpenSSL) if \*(UA has been compiled to support this.
7259 Remember that for this
7261 refers to the variable
7263 (or, if that contains multiple addresses,
7269 \*(OP Normally \*(UA invokes the program defined via
7271 to transfer messages, as described in
7272 .Sx "On sending mail, and non-interactive mode" .
7275 variable will instead cause SMTP network connections be made to the
7276 server specified therein in order to directly submit the message.
7277 \*(UA knows about three different
7278 .Dq SMTP protocols :
7280 .Bl -bullet -compact
7282 The plain SMTP protocol (RFC 5321) that normally lives on the
7283 server port 25 and requires setting the
7284 .Va smtp-use-starttls
7285 variable to enter a SSL/TLS encrypted session state.
7286 Assign a value like \*(IN
7287 .Ql [smtp://][user[:password]@]server[:port]
7289 .Ql [smtp://]server[:port] )
7290 to choose this protocol.
7292 Then the so-called SMTPS which is supposed to live on server port 465
7293 and is automatically SSL/TLS secured.
7294 Unfortunately it never became a standardized protocol and may thus not
7295 be supported by your hosts network service database
7296 \(en in fact the port number has already been reassigned to other
7299 SMTPS is nonetheless a commonly offered protocol and thus can be
7300 chosen by assigning a value like \*(IN
7301 .Ql smtps://[user[:password]@]server[:port]
7303 .Ql smtps://server[:port] ) ;
7304 due to the mentioned problems it is usually necessary to explicitly
7309 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7310 lives on server port 587 and is practically identically to the SMTP
7311 protocol from \*(UA's point of view beside that; it requires setting the
7312 .Va smtp-use-starttls
7313 variable to enter a SSL/TLS secured session state.
7314 Assign a value like \*(IN
7315 .Ql submission://[user[:password]@]server[:port]
7317 .Ql submission://server[:port] ) .
7320 For more on credentials etc. please see
7321 .Sx "On URL syntax and credential lookup" .
7322 The SMTP transfer is executed in a child process, which runs
7323 asynchronously unless either the
7328 If it receives a TERM signal, it will abort and save the message to
7333 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7334 \*(OP Variable chain that sets the SMTP authentication method.
7341 as well as the \*(OPal methods
7347 method doesn't need any user credentials,
7349 requires a user name and all other methods require a user name and
7357 .Va smtp-auth-password
7359 .Va smtp-auth-user ) .
7364 .Va smtp-auth-USER@HOST :
7365 may override dependend on sender address in the variable
7368 .It Va smtp-auth-password
7369 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7370 If the authentication method requires a password, but neither
7371 .Va smtp-auth-password
7373 .Va smtp-auth-password-USER@HOST
7375 \*(UA will ask for a password on the user's terminal.
7377 .It Va smtp-auth-password-USER@HOST
7379 .Va smtp-auth-password
7380 for specific values of sender addresses, dependent upon the variable
7383 .It Va smtp-auth-user
7384 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7385 If the authentication method requires a user name, but neither
7388 .Va smtp-auth-user-USER@HOST
7390 \*(UA will ask for a user name on the user's terminal.
7392 .It Va smtp-auth-user-USER@HOST
7395 for specific values of sender addresses, dependent upon the variable
7399 .It Va smtp-hostname
7400 \*(IN Normally \*(UA uses the variable
7402 to derive the necessary
7404 information to issue a
7409 can be used to use the
7411 from the SMTP account
7418 from the content of this variable (or, if that is the empty string,
7420 or the local hostname as a last resort).
7421 This often allows using an address that is itself valid but hosted by
7422 a provider other than which (in
7424 is about to send the message.
7425 Setting this variable also influences the generated
7428 .Mx Va smtp-use-starttls
7429 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7430 \*(BO\*(OP Causes \*(UA to issue a
7432 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7433 transport layer security.
7437 .It Va spam-interface
7438 \*(OP In order to use any of the spam-related commands (like, e.g.,
7440 the desired spam interface must be defined by setting this variable.
7441 Please refer to the manual section
7443 for the complete picture of spam handling in \*(UA.
7444 All or none of the following interfaces may be available:
7446 .Bl -tag -width ".It Ql _ilte_"
7452 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7454 Different to the generic filter interface \*(UA will automatically add
7455 the correct arguments for a given command and has the necessary
7456 knowledge to parse the program's output.
7459 will have been compiled into the \*(UA binary if
7464 Shall it be necessary to define a specific connection type (rather than
7465 using a configuration file for that), the variable
7467 can be used as in, e.g.,
7468 .Ql -d server.example.com -p 783 .
7469 It is also possible to specify a per-user configuration via
7471 Note that this interface doesn't inspect the
7473 flag of a message for the command
7477 \*(UA will directly communicate with the
7483 stream socket as specified in
7485 It is possible to specify a per-user configuration via
7489 generic spam filter support via freely configurable hooks.
7490 This interface is ment for programs like
7494 and requires according behaviour in respect to the hooks' exit
7495 status for at least the command
7498 meaning a message is spam,
7502 for unsure and any other return value indicating a hard error);
7503 since the hooks can include shell code snippets diverting behaviour
7504 can be intercepted as necessary.
7506 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7509 .Va spamfilter-spam ;
7512 contains examples for some programs.
7513 The process environment of the hooks will have the variables
7514 .Ev NAIL_TMPDIR , TMPDIR
7516 .Ev NAIL_FILENAME_GENERATED
7518 Note that spam score support for
7520 isn't supported unless the \*(OPtional regular expression support is
7522 .Va spamfilter-rate-scanscore
7529 \*(OP Messages that exceed this size won't be passed through to the
7531 .Va spam-interface .
7532 The default is 420000 bytes.
7535 .It Va spamc-command
7536 \*(OP The path to the
7540 .Va spam-interface .
7541 Note that the path is not expanded, but used
7543 A fallback path will have been compiled into the \*(UA binary if the
7544 executable had been found during compilation.
7547 .It Va spamc-arguments
7548 \*(OP Even though \*(UA deals with most arguments for the
7551 automatically, it may at least sometimes be desirable to specifiy
7552 connection-related ones via this variable, e.g.,
7553 .Ql -d server.example.com -p 783 .
7557 \*(OP Specify a username for per-user configuration files for the
7559 .Va spam-interface .
7560 If this is set to the empty string then \*(UA will use the name of the
7566 \*(OP Specify the path of the
7568 domain socket on which
7570 listens for connections for the
7572 .Va spam-interface .
7573 Note that the path is not expanded, but used
7578 \*(OP Specify a username for per-user configuration files for the
7580 .Va spam-interface .
7581 If this is set to the empty string then \*(UA will use the name of the
7590 .It Va spamfilter-ham , spamfilter-noham , \
7591 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7592 \*(OP Command and argument hooks for the
7594 .Va spam-interface .
7597 contains examples for some programs.
7600 .It Va spamfilter-rate-scanscore
7601 \*(OP Because of the generic nature of the
7604 spam scores are not supported for it by default, but if the \*(OPtional
7605 regular expression support is available then setting this variable can
7606 be used to overcome this restriction.
7607 It is interpreted as follows: first a number (digits) is parsed that
7608 must be followed by a semicolon
7610 and an extended regular expression.
7611 Then the latter is used to parse the first output line of the
7613 hook, and, in case the evaluation is successful, the group that has been
7614 specified via the number is interpreted as a floating point scan score.
7618 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7619 Enhanced Mail) for verification of of SSL/TLS server certificates.
7621 .Xr SSL_CTX_load_verify_locations 3
7622 for more information.
7626 \*(OP Specifies a file with CA certificates in PEM format for
7627 verification of SSL/TLS server certificates.
7629 .Xr SSL_CTX_load_verify_locations 3
7630 for more information.
7633 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7634 \*(OP Variable chain that sets the file name for a SSL/TLS client
7635 certificate required by some servers.
7636 This is a direct interface to the
7640 function of the OpenSSL library, if available.
7642 .Mx Va ssl-cipher-list
7643 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7644 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7645 This is a direct interface to the
7649 function of the OpenSSL library, if available; see
7651 for more information.
7652 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7654 specific cipher (protocol standards ship with a list of acceptable
7655 ciphers), possibly cramped to what the actually used SSL/TLS library
7656 supports \(en the manual section
7657 .Sx "An example configuration"
7658 also contains a SSL/TLS use case.
7661 .It Va ssl-config-file
7662 \*(OP If this variable is set \*(UA will call
7663 .Xr CONF_modules_load_file 3
7664 to allow OpenSSL to be configured according to the host system wide
7666 If a non-empty value is given then this will be used to specify the
7667 configuration file to be used instead of the global OpenSSL default;
7668 note that in this case it is an error if the file cannot be loaded.
7669 The application name will always be passed as
7674 \*(OP Specifies a file that contains a CRL in PEM format to use when
7675 verifying SSL/TLS server certificates.
7679 \*(OP Specifies a directory that contains files with CRLs in PEM format
7680 to use when verifying SSL/TLS server certificates.
7683 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7684 \*(OP Variable chain that sets the file name for the private key of
7685 a SSL/TLS client certificate.
7686 If unset, the name of the certificate file is used.
7687 The file is expected to be in PEM format.
7688 This is a direct interface to the
7692 function of the OpenSSL library, if available.
7695 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7697 \*(OB Please use the newer and more flexible
7699 instead: if both values are set,
7701 will take precedence!
7702 Can be set to the following values, the actually used
7704 specification to which it is mapped is shown in parenthesis:
7706 .Pf ( Ql -ALL, TLSv1.2 ) ,
7708 .Pf ( Ql -ALL, TLSv1.1 ) ,
7710 .Pf ( Ql -ALL, TLSv1 )
7713 .Pf ( Ql -ALL, SSLv3 ) ;
7718 and thus includes the SSLv3 protocol.
7719 Note that SSLv2 is no longer supported at all.
7722 .It Va ssl-no-default-ca
7723 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7727 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7728 \*(OP Specify the used SSL/TLS protocol.
7729 This is a direct interface to the
7733 function of the OpenSSL library, if available;
7734 otherwise an \*(UA internal parser is used which understands the
7735 following subset of (case-insensitive) command strings:
7741 as well as the special value
7743 Multiple specifications may be given via a comma-separated list which
7744 ignores any whitespace.
7747 plus prefix will enable a protocol, a
7749 minus prefix will disable it, so that
7751 will enable only the TLSv1.2 protocol.
7753 It depends upon the used TLS/SSL library which protocols are actually
7754 supported and which protocols are used if
7756 is not set, but note that SSLv2 is no longer supported at all and
7758 Especially for older protocols explicitly securing
7760 may be worthwile, see
7761 .Sx "An example configuration" .
7765 \*(OP Gives the pathname to an entropy daemon socket, see
7767 Not all SSL/TLS libraries support this.
7770 .It Va ssl-rand-file
7771 \*(OP Gives the filename to a file with random entropy data, see
7772 .Xr RAND_load_file 3 .
7773 If this variable is not set, or set to the empty string, or if the
7774 filename expansion failed, then
7775 .Xr RAND_file_name 3
7776 will be used to create the filename if, and only if,
7778 documents that the SSL PRNG is not yet sufficiently seeded.
7779 If \*(UA successfully seeded the SSL PRNG then it'll update the file via
7780 .Xr RAND_write_file 3 .
7781 This variable is only used if
7783 is not set (or not supported by the SSL/TLS library).
7786 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7787 \*(OP Variable chain that sets the action to be performed if an error
7788 occurs during SSL/TLS server certificate validation.
7789 Valid (case-insensitive) values are
7791 (fail and close connection immediately),
7793 (ask whether to continue on standard input),
7795 (show a warning and continue),
7797 (do not perform validation).
7803 If only set without an assigned value, then this option inhibits the
7808 header fields that include obvious references to \*(UA.
7809 There are two pitfalls associated with this:
7810 First, the message id of outgoing messages is not known anymore.
7811 Second, an expert may still use the remaining information in the header
7812 to track down the originating mail user agent.
7817 suppression doesn't occur.
7822 (\*(OP) This specifies a comma-separated list of
7825 .Sx "On terminal control and line editor" ,
7826 escape commas with backslash) to be used to overwrite or define entries.
7828 that this variable will only be queried once at program startup and can
7829 thus only be specified in resource files or on the command line.
7832 String capabilities form
7834 pairs and are expected unless noted otherwise.
7835 Numerics have to be notated as
7837 where the number is expected in normal decimal notation.
7838 Finally, booleans don't have any value but indicate a true or false
7839 state simply by being defined or not; this indeed means that \*(UA
7840 doesn't support undefining a boolean that normally exists.
7841 The following example defines entries for combinations of
7842 .Ql control-CURSOR :
7844 .Bd -literal -offset indent
7845 set termcap="%k=\e033[D,%o=\e033[C,%q=\e033[A,%r=\e033[B"
7849 Keycodes can easily be detected with the command
7851 by running it on an interactive terminal via
7855 command line option if available) and pressing some keys: here
7863 (actually a visualized numeric where
7865 stands for 1 etc.; in fact: the numeric value of
7867 in the US-ASCII character set bitwise XORd with
7870 .Ql $ echo $((0x41 ^ 0x40)) .
7873 and other control characters have to be notated as shell-style
7874 escape sequences, e.g.,
7884 The following terminal capabilities are or may be meaningful for the
7885 operation of the builtin line editor or \*(UA in general:
7888 .Bl -tag -compact -width yay
7891 .Cd max_colors Ns / Ns Cd colors :
7892 numeric capability specifying the maximum number of colours.
7893 Note that \*(UA doesn't actually care about the terminal beside that,
7894 but always emits ANSI/ISO 6429 escape sequences for producing the
7895 colour and font attributes.
7899 .Cd exit_ca_mode Ns / Ns Cd rmcup
7901 .Cd enter_ca_mode Ns / Ns Cd smcup ,
7902 respectively: exit and enter the alternative screen
7904 effectively turning \*(UA into a fullscreen application.
7905 To disable that, set (at least) one to the empty string.
7908 .Cd keypad_xmit Ns / Ns Cd smkx
7910 .Cd keypad_local Ns / Ns Cd rmkx ,
7911 respectively: enable and disable the keypad.
7912 This is always enabled if available, because it seems even keyboards
7913 without keypads generate other key codes for, e.g., cursor keys in that
7914 case, and only if enabled we see the codes that we are interested in.
7917 .Cd clr_eos Ns / Ns Cd ed :
7921 .Cd clear_screen Ns / Ns Cd clear :
7922 clear the screen and home cursor.
7923 (Will be simulated via
7929 .Cd cursor_home Ns / Ns Cd home :
7934 .Cd clr_eol Ns / Ns Cd el :
7935 clear to the end of line.
7936 (Will be simulated via
7938 plus repititions of space characters.)
7941 .Cd column_address Ns / Ns Cd hpa :
7942 move the cursor (to the given column parameter) in the current row.
7943 (Will be simulated via
7949 .Cd carriage_return Ns / Ns Cd cr :
7950 move to the first column in the current row.
7951 The default builtin fallback is
7955 .Cd cursor_left Ns / Ns Cd cub1 :
7956 move the cursor left one space (non-destructively).
7957 The default builtin fallback is
7961 .Cd cursor_right Ns / Ns Cd cuf1 :
7962 move the cursor right one space (non-destructively).
7963 The default builtin fallback is
7965 which is used by most terminals.
7971 .It Cd %k , %o , %q , %r
7972 The left, right, up and down cursor keys with the
7979 .It Va termcap-disable
7980 \*(OP Disable any interaction with the
7982 If set only some generic fallback builtins and possibly the content of
7984 describe the terminal to \*(UA.
7986 that this variable will only be queried once at program startup and can
7987 thus only be specified in resource files or on the command line.
7991 If defined, gives the number of lines of a message to be displayed
7994 normally, the first five lines are printed.
7998 The character set of the terminal \*(UA operates on,
7999 and the one and only supported character set that \*(UA can use if no
8000 character set conversion capabilities have been compiled into it,
8001 in which case it defaults to ISO-8859-1 unless it can deduce a value
8005 Refer to the section
8006 .Sx "Character sets"
8007 for the complete picture about character sets.
8010 .It Va user-HOST , user
8011 \*(IN Variable chain that sets a global fallback user name, which is
8012 used in case none has been given in the protocol and account-specific
8014 This variable defaults to the value of the first of
8018 that is set (the former being SystemV and POSIX standard, the latter BSD).
8022 \*(BO Setting this option enables upward compatibility with \*(UA
8023 version 15.0 in respect to which configuration options are available and
8024 how they are handled.
8025 This manual uses \*(IN and \*(OU to refer to the new and the old way of
8026 doing things, respectively.
8030 \*(BO Setting this option, also controllable via the command line option
8032 causes \*(UA to be more verbose, e.g., it will display obsoletion
8033 warnings and SSL/TLS certificate chains.
8034 Even though marked \*(BO this option may be set twice in order to
8035 increase the level of verbosity even more, in which case even details of
8036 the actual message delivery and protocol conversations are shown.
8039 is sufficient to disable verbosity as such.
8045 .It Va version , version-major , version-minor , version-update
8046 \*(RO \*(UA version information: the first variable contains a string
8047 containing the complete version identification \(en this is identical to
8048 the output of the command
8050 The latter three contain only digits: the major, minor and update
8054 .It Va writebackedited
8055 If this variable is set messages modified using the
8059 commands are written back to the current folder when it is quit;
8060 it is only honoured for writable folders in MBOX format, though.
8061 Note that the editor will be pointed to the raw message content in that
8062 case, i.e., neither MIME decoding nor decryption will have been
8063 performed, and proper RFC 4155
8065 quoting of newly added or edited content is also left as an excercise to
8069 .\" }}} (INTERNAL VARIABLES)
8072 .\" .Sh ENVIRONMENT {{{
8076 .Dq environment variable
8077 should be considered an indication that the following variables are
8078 either standardized as being vivid parts of process environments, or
8079 are commonly found in there.
8080 The process environment is inherited from the
8082 once \*(UA is started, and unless otherwise explicitly noted variables
8083 in there integrate into the normal handling of
8084 .Sx "INTERNAL VARIABLES" ,
8085 from \*(UAs point of view, i.e., they can be
8087 as such in resource files and need not necessarily come from the process
8088 environment and be managed via
8092 E.g., the following example, applicable to a POSIX shell, sets the
8094 environment variable for \*(UA only, and beforehand exports the
8096 in order to affect any further processing in the running shell:
8098 .Bd -literal -offset indent
8099 $ EDITOR="vim -u ${HOME}/.vimrc"
8101 $ COLUMNS=80 \*(ua -R
8104 .Bl -tag -width ".It Ev _AILR_"
8107 The user's preferred width in column positions for the terminal screen
8109 Queried and used once on program startup.
8113 The name of the file to use for saving aborted messages if
8115 is set; this defaults to
8123 Pathname of the text editor to use in the
8127 .Sx "TILDE ESCAPES" .
8128 A default editor is used if this value is not defined.
8132 The user's home directory.
8133 This variable is only used when it resides in the process environment.
8136 to update the value at runtime.
8143 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
8147 .Sx "Character sets" .
8151 The user's preferred number of lines on a page or the vertical screen
8152 or window size in lines.
8153 Queried and used once on program startup.
8157 Pathname of the directory lister to use in the
8159 command when operating on local mailboxes.
8162 (path search through
8167 Force identification as the given user, i.e., identical to the
8169 command line option.
8170 This variable is standardized and therefore used in preference to the
8173 it is only used when it resides in the process environment.
8174 \*(ID The variable can be updated at runtime via
8176 but without having an effect on \*(UA itself.
8180 Is used as the user's mailbox, if set.
8181 Otherwise, a system-dependent default is used.
8182 Supports a logical subset of the special conventions that are documented
8191 \*(OP Overrides the default path search for
8192 .Sx "The Mailcap files" ,
8193 which is defined in the standard RFC 1524 as
8194 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
8195 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8196 (\*(UA makes it a configuration option, however.)
8197 Note this is not a search path, but a path search.
8201 Is used as a startup file instead of
8204 When \*(UA scripts are invoked on behalf of other users,
8205 either this variable should be set to
8209 command line option should be used in order to avoid side-effects from
8210 reading their configuration files.
8211 This variable is only used when it resides in the process environment.
8215 The name of the user's mbox file.
8216 A logical subset of the special conventions that are documented for the
8221 The fallback default is
8226 Traditionally this secondary mailbox is used as the file to save
8227 messages from the system mailbox that have been read.
8229 .Sx "Message states" .
8232 .It Ev NAIL_NO_SYSTEM_RC
8233 If this variable is set then reading of
8235 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8236 had been started up with the option
8238 This variable is only used when it resides in the process environment.
8242 \*(IN\*(OP This variable overrides the default location of the user's
8248 Pathname of the program to use in the more command or when the
8251 The default paginator is
8253 (path search through
8258 A list of directories that is searched by the shell when looking for
8259 commands (as such only recognized in the process environment).
8263 The shell to use for the commands
8269 and when starting subprocesses.
8270 A default shell is used if this option is not defined.
8274 \*(OP The terminal type for which output is to be prepared.
8275 For extended colour and font control please refer to
8276 .Sx "Coloured display" ,
8277 and for terminal management in general to
8278 .Sx "On terminal control and line editor" .
8282 Used as directory for temporary files instead of
8285 This variable is only used when it resides in the process environment.
8288 to update the value at runtime.
8292 This variable comes from the BSD world and is only used if the POSIX
8293 standard environment variable
8295 which originates in SysV
8298 Force identification as the given user, i.e., identical to the
8300 command line option.
8301 This variable is only used when it resides in the process environment.
8302 \*(ID The variable can be updated at runtime via
8304 but without having an effect on \*(UA itself.
8308 Pathname of the text editor to use in the
8312 .Sx "TILDE ESCAPES" .
8320 .Bl -tag -width ".It Pa _etc/mime.type_"
8322 File giving initial commands.
8325 System wide initialization file.
8329 \*(OP Personal MIME type handler definition file, see
8330 .Sx "The Mailcap files" .
8331 (RFC 1524 location, the actual path is a configuration option.)
8335 \*(OP System wide MIME type handler definition file, see
8336 .Sx "The Mailcap files" .
8337 (RFC 1524 location, the actual path is a configuration option.)
8340 .It Pa ~/.mime.types
8341 Personal MIME types, see
8342 .Sx "The mime.types files" .
8345 .It Pa /etc/mime.types
8346 System wide MIME types, see
8347 .Sx "The mime.types files" .
8351 \*(IN\*(OP The default location of the users
8353 file \(en the section
8354 .Sx "The .netrc file"
8355 documents the file format.
8358 .\" .Ss "The mime.types files" {{{
8359 .Ss "The mime.types files"
8361 When sending messages \*(UA tries to determine the content type of all
8363 When displaying message content or attachments \*(UA uses the content
8364 type to decide wether it can directly display data or wether it needs to
8365 deal with content handlers.
8366 It learns about MIME types and how to treat them by reading
8368 files, the loading of which can be controlled by setting the variable
8369 .Va mimetypes-load-control .
8372 can also be used to deal with MIME types.)
8374 files have the following syntax:
8377 .Dl type/subtype extension [extension ...]
8382 are strings describing the file contents, and one or multiple
8384 s, separated by whitespace, name the part of a filename starting after
8385 the last dot (of interest).
8386 Comments may be introduced anywhere on a line with a number sign
8388 causing the remaining line to be discarded.
8390 \*(UA also supports an extended, non-portable syntax in specially
8391 crafted files, which can be loaded via the alternative value syntax of
8392 .Va mimetypes-load-control
8393 and prepends an optional
8397 .Dl [type-marker ]type/subtype extension [extension ...]
8400 The following type markers are supported:
8403 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8405 Treat message parts with this content as plain text.
8410 Treat message parts with this content as HTML tagsoup.
8411 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8412 the content as plain text instead.
8416 but instead of falling back to plain text require an explicit content
8417 handler to be defined.
8422 for sending messages:
8424 .Va mime-allow-text-controls ,
8425 .Va mimetypes-load-control .
8426 For reading etc. messages:
8427 .Sx "HTML mail and MIME attachments" ,
8428 .Sx "The Mailcap files" ,
8430 .Va mime-counter-evidence ,
8431 .Va mimetypes-load-control ,
8432 .Va pipe-TYPE/SUBTYPE ,
8433 .Va pipe-EXTENSION .
8436 .\" .Ss "The Mailcap files" {{{
8437 .Ss "The Mailcap files"
8440 .Dq User Agent Configuration Mechanism
8441 which \*(UA \*(OPally supports.
8442 It defines a file format to be used to inform mail user agent programs
8443 about the locally-installed facilities for handling various data
8444 formats, i.e., about commands and how they can be used to display, edit
8445 etc. MIME part contents, as well as a default path search that includes
8446 multiple possible locations of
8450 environment variable that can be used to overwrite that (repeating here
8451 that it is not a search path, but instead a path search specification).
8452 Any existing files will be loaded in sequence, appending any content to
8453 the list of MIME type handler directives.
8457 files consist of a set of newline separated entries.
8458 Comment lines start with a number sign
8460 (in the first column!) and are ignored.
8461 Empty lines are also ignored.
8462 All other lines form individual entries that must adhere to the syntax
8464 To extend a single entry (not comment) its line can be continued on
8465 follow lines if newline characters are
8467 by preceding them with the backslash character
8469 The standard doesn't specify how leading whitespace of follow lines is
8470 to be treated, therefore \*(UA retains it.
8474 entries consist of a number of semicolon
8476 separated fields, and the backslash
8478 character can be used to escape any following character including
8479 semicolon and itself.
8480 The first two fields are mandatory and must occur in the specified
8481 order, the remaining fields are optional and may appear in any order.
8482 Leading and trailing whitespace of content is ignored (removed).
8485 The first field defines the MIME
8487 the entry is about to handle (case-insensitively, and no backslash
8488 escaping is possible in this field).
8489 If the subtype is specified as an asterisk
8491 the entry is ment to match all subtypes of the named type, e.g.,
8493 would match any audio type.
8494 The second field defines the shell command which shall be used to
8496 MIME parts of the given type; it is implicitly called the
8503 shell commands message (MIME part) data is passed via standard input
8504 unless the given shell command includes one or more instances of the
8507 in which case these instances will be replaced with a temporary filename
8508 and the data will have been stored in the file that is being pointed to.
8511 shell commands data is assumed to be generated on standard output unless
8512 the given command includes (one ore multiple)
8514 In any case any given
8516 format is replaced with a(n already) properly quoted filename.
8517 Note that when a command makes use of a temporary file via
8519 then \*(UA will remove it again, as if the
8520 .Cd x-mailx-tmpfile ,
8521 .Cd x-mailx-tmpfile-fill
8523 .Cd x-mailx-tmpfile-unlink
8524 flags had been set; see below for more.
8527 The optional fields either define a shell command or an attribute (flag)
8528 value, the latter being a single word and the former being a keyword
8529 naming the field followed by an equals sign
8531 succeeded by a shell command, and as usual for any
8533 content any whitespace surrounding the equals sign will be removed, too.
8534 Optional fields include the following:
8537 .Bl -tag -width textualnewlines
8539 A program that can be used to compose a new body or body part in the
8546 field, but is to be used when the composing program needs to specify the
8548 header field to be applied to the composed data.
8552 A program that can be used to edit a body or body part in the given
8557 A program that can be used to print a message or body part in the given
8562 Specifies a program to be run to test some condition, e.g., the machine
8563 architecture, or the window system in use, to determine whether or not
8564 this mailcap entry applies.
8565 If the test fails, a subsequent mailcap entry should be sought; also see
8566 .Cd x-mailx-test-once .
8568 .It Cd needsterminal
8569 This flag field indicates that the given shell command must be run on
8570 an interactive terminal.
8571 \*(UA will temporarily release the terminal to the given command in
8572 interactive mode, in non-interactive mode this entry will be entirely
8573 ignored; this flag implies
8574 .Cd x-mailx-noquote .
8576 .It Cd copiousoutput
8577 A flag field which indicates that the output of the
8579 command will be an extended stream of textual output that can be
8580 (re)integrated into \*(UA's normal visual display.
8581 It is mutually exclusive with
8584 .Cd x-mailx-always .
8586 .It Cd textualnewlines
8587 A flag field which indicates that this type of data is line-oriented and
8590 all newlines should be converted to canonical form (CRLF) before
8591 encoding, and will be in that form after decoding.
8595 This field gives a file name format, in which
8597 will be replaced by a random string, the joined combination of which
8598 will be used as the filename denoted by
8599 .Ev NAIL_FILENAME_TEMPORARY .
8600 One could specify that a GIF file being passed to an image viewer should
8601 have a name ending in
8604 .Ql nametemplate=%s.gif .
8605 Note that \*(UA ignores the name template unless that solely specifies
8606 a filename suffix that consists of (ASCII) alphabetic and numeric
8607 characters, the underscore and dot only.
8610 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8611 icon to be used to visually denote the presence of this kind of data.
8612 This field is not used by \*(UA.
8615 A textual description that describes this type of data.
8617 .It Cd x-mailx-always
8618 Extension flag field that denotes that the given
8620 command shall be executed even if multiple messages will be displayed
8622 Normally messages which require external viewers that produce output
8623 which doesn't integrate into \*(UA's visual display (i.e., don't have
8625 set) have to be addressed directly and individually.
8626 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8629 .It Cd x-mailx-even-if-not-interactive
8630 An extension flag test field \(em by default handlers without
8632 are entirely ignored in non-interactive mode, but if this flag is set
8633 then their use will be considered.
8634 It is an error if this flag is set for commands that use the flag
8637 .It Cd x-mailx-noquote
8638 An extension flag field that indicates that even a
8641 command shall not be used to generate message quotes
8642 (as it would be by default).
8644 .It Cd x-mailx-async
8645 Extension flag field that denotes that the given
8647 command shall be executed asynchronously, without blocking \*(UA.
8648 Cannot be used in conjunction with
8651 .It Cd x-mailx-test-once
8652 Extension flag which denotes wether the given
8654 command shall be evaluated once only and the (boolean) result be cached.
8655 This is handy if some global unchanging condition is to be queried, like
8656 .Dq running under the X Window System .
8658 .It Cd x-mailx-tmpfile
8659 Extension flag field that requests creation of a zero-sized temporary
8660 file, the name of which is to be placed in the environment variable
8661 .Ev NAIL_FILENAME_TEMPORARY .
8662 It is an error to use this flag with commands that include a
8666 .It Cd x-mailx-tmpfile-fill
8667 Normally the MIME part content is passed to the handler via standard
8668 input; if this flag is set then the data will instead be written into
8670 .Cd x-mailx-tmpfile .
8671 In order to cause deletion of the temporary file you will have to set
8672 .Cd x-mailx-tmpfile-unlink
8674 It is an error to use this flag with commands that include a
8678 .It Cd x-mailx-tmpfile-unlink
8679 Extension flag field that requests that the temporary file shall be
8680 deleted automatically when the command loop is entered again at latest.
8681 (Don't use this for asynchronous handlers.)
8682 It is an error to use this flag with commands that include a
8684 format, or without also setting
8687 .Cd x-mailx-tmpfile-fill .
8689 .It Cd x-mailx-tmpfile-keep
8692 implies the three tmpfile related flags above, but if you want, e.g.,
8694 and deal with the temporary file yourself, you can add in this flag to
8696 .Cd x-mailx-tmpfile-unlink .
8701 The standard includes the possibility to define any number of additional
8702 entry fields, prefixed by
8704 Flag fields apply to the entire
8706 entry \(em in some unusual cases, this may not be desirable, but
8707 differentiation can be accomplished via separate entries, taking
8708 advantage of the fact that subsequent entries are searched if an earlier
8709 one does not provide enough information.
8712 command needs to specify the
8716 command shall not, the following will help out the latter (with enabled
8720 level \*(UA will show informations about handler evaluation):
8722 .Bd -literal -offset indent
8723 application/postscript; ps-to-terminal %s; needsterminal
8724 application/postscript; ps-to-terminal %s; compose=idraw %s
8728 In fields any occurrence of the format string
8730 will be replaced by the
8733 Named parameters from the
8735 field may be placed in the command execution line using
8737 followed by the parameter name and a closing
8740 The entire parameter should appear as a single command line argument,
8741 regardless of embedded spaces; thus:
8743 .Bd -literal -offset indent
8745 Content-type: multipart/mixed; boundary=42
8748 multipart/*; /usr/local/bin/showmulti \e
8749 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8751 # Executed shell command
8752 /usr/local/bin/showmulti multipart/mixed 42
8756 .\" TODO v15: Mailcap: %n,%F
8757 Note that \*(UA doesn't support handlers for multipart MIME parts as
8758 shown in this example (as of today).
8759 \*(UA doesn't support the additional formats
8763 An example file, also showing how to properly deal with the expansion of
8765 which includes any quotes that are necessary to make it a valid shell
8766 argument by itself and thus will cause undesired behaviour when placed
8767 in additional user-provided quotes:
8769 .Bd -literal -offset indent
8771 text/richtext; richtext %s; copiousoutput
8773 text/x-perl; perl -cWT %s
8777 trap "rm -f ${infile}" EXIT\e; \e
8778 trap "exit 75" INT QUIT TERM\e; \e
8780 x-mailx-async; x-mailx-tmpfile-keep
8782 application/*; echo "This is \e"%t\e" but \e
8783 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
8784 copiousoutput; x-mailx-noquote
8789 .Sx "HTML mail and MIME attachments" ,
8790 .Sx "The mime.types files" ,
8793 .Va mime-counter-evidence ,
8794 .Va pipe-TYPE/SUBTYPE ,
8795 .Va pipe-EXTENSION .
8798 .\" .Ss "The .netrc file" {{{
8799 .Ss "The .netrc file"
8803 file contains user credentials for machine accounts.
8804 The default location in the user's
8806 directory may be overridden by the
8808 environment variable.
8809 The file consists of space, tabulator or newline separated tokens.
8810 \*(UA implements a parser that supports a superset of the original BSD
8811 syntax, but users should nonetheless be aware of portability glitches
8812 of that file format, shall their
8814 be usable across multiple programs and platforms:
8817 .Bl -bullet -compact
8819 BSD doesn't support single, but only double quotation marks, e.g.,
8820 .Ql password="pass with spaces" .
8822 BSD (only?) supports escaping of single characters via a backslash
8823 (e.g., a space can be escaped via
8825 in- as well as outside of a quoted string.
8827 BSD doesn't require the final quotation mark of the final user input token.
8829 The original BSD (Berknet) parser also supported a format which allowed
8830 tokens to be separated with commas \(en whereas at least Hewlett-Packard
8831 still seems to support this syntax, \*(UA does not!
8833 As a non-portable extension some widely-used programs support
8834 shell-style comments: if an input line starts, after any amount of
8835 whitespace, with a number sign
8837 then the rest of the line is ignored.
8839 Whereas other programs may require that the
8841 file is accessible by only the user if it contains a
8847 \*(UA will always require these strict permissions.
8851 Of the following list of supported tokens \*(UA only uses (and caches)
8856 At runtime the command
8858 can be used to control \*(UAs
8862 .Bl -tag -width password
8863 .It Cd machine Ar name
8864 The hostname of the entries' machine, lowercase-normalized by \*(UA
8866 Any further file content, until either end-of-file or the occurrence
8871 first-class token is bound (only related) to the machine
8874 As an extension that shouldn't be the cause of any worries
8875 \*(UA supports a single wildcard prefix for
8877 .Bd -literal -offset indent
8878 machine *.example.com login USER password PASS
8879 machine pop3.example.com login USER password PASS
8880 machine smtp.example.com login USER password PASS
8886 .Ql pop3.example.com ,
8890 .Ql local.smtp.example.com .
8891 Note that in the example neither
8892 .Ql pop3.example.com
8894 .Ql smtp.example.com
8895 will be matched by the wildcard, since the exact matches take
8896 precedence (it is however faster to specify it the other way around).
8901 except that it is a fallback entry that is used shall none of the
8902 specified machines match; only one default token may be specified,
8903 and it must be the last first-class token.
8905 .It Cd login Ar name
8906 The user name on the remote machine.
8908 .It Cd password Ar string
8909 The user's password on the remote machine.
8911 .It Cd account Ar string
8912 Supply an additional account password.
8913 This is merely for FTP purposes.
8915 .It Cd macdef Ar name
8917 A macro is defined with the specified
8919 it is formed from all lines beginning with the next line and continuing
8920 until a blank line is (consecutive newline characters are) encountered.
8923 entries cannot be utilized by multiple machines, too, but must be
8924 defined following the
8926 they are intended to be used with.)
8929 exists, it is automatically run as the last step of the login process.
8930 This is merely for FTP purposes.
8937 .\" .Sh EXAMPLES {{{
8940 .\" .Ss "An example configuration" {{{
8941 .Ss "An example configuration"
8943 .Bd -literal -offset indent
8944 # This example assumes v15.0 compatibility mode
8947 # Where are the up-to-date SSL certificates?
8948 #set ssl-ca-dir=/etc/ssl/certs
8949 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8951 # (Since we manage up-to-date ones explicitly, don't use any,
8952 # possibly outdated, default certificates shipped with OpenSSL
8953 set ssl-no-default-ca
8955 # Don't use protocols older than TLS v1.2.
8956 # Change this only when the remote server doesn't support it:
8957 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
8958 # such explicit exceptions, then
8959 set ssl-protocol="-ALL,+TLSv1.2"
8961 # Explicitly define the list of ciphers, which may improve security,
8962 # especially with protocols older than TLS v1.2. See ciphers(1).
8963 # Hint: it is important to include "@STRENGTH": only with it the
8964 # final list will be sorted by algorithm strength.
8965 # This is an example: in reality it is possibly best to only use
8966 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
8967 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
8968 !MD5:!RC4:!EXPORT:@STRENGTH"
8970 # Request strict transport security checks!
8971 set ssl-verify=strict
8973 # Essential setting: select allowed character sets
8974 set sendcharsets=utf-8,iso-8859-1
8976 # A very kind option: when replying to a message, first try to
8977 # use the same encoding that the original poster used herself!
8978 set reply-in-same-charset
8980 # When replying to or forwarding a message the comment and name
8981 # parts of email addresses are removed unless this variable is set
8984 # When sending messages, wait until the Mail-Transfer-Agent finishs.
8985 # Only like this you'll be able to see errors reported through the
8986 # exit status of the MTA (including the builtin SMTP one)!
8989 # Only use builtin MIME types, no mime.types(5) files
8990 set mimetypes-load-control
8992 # Default directory where we act in (relative to $HOME)
8994 # A leading "+" (often) means: under *folder*
8995 # *record* is used to save copies of sent messages
8996 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
8998 # Make "file mymbox" and "file myrec" go to..
8999 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
9001 # Not really optional, e.g., for S/MIME
9002 set from="Your Name <youremail@domain>"
9004 # It may be necessary to set hostname and/or smtp-hostname
9005 # if the "SERVER" of smtp and "domain" of from don't match.
9006 # The `urlencode' command can be used to encode USER and PASS
9007 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
9008 smtp-auth=login/plain... \e
9011 # Never refuse to start into interactive mode, and more
9013 colour-pager crt= \e
9014 followup-to followup-to-honour=ask-yes \e
9015 history-file=+.\*(uahist history-size=-1 history-gabby \e
9016 mime-counter-evidence=0xE \e
9017 prompt="\e033[31m?\e?[\e$ \e@]\e& \e033[0m" \e
9018 reply-to-honour=ask-yes
9020 # When `p'rinting messages, show only these headers
9021 # (use `P'rint for all headers and `S'how for raw message)
9022 retain date from to cc subject
9024 # Some mailing lists
9025 mlist @xyz-editor.xyz$ @xyzf.xyz$
9026 mlsubscribe ^xfans@xfans.xyz$
9028 # A real life example of a very huge free mail provider
9030 set from="Your Name <youremail@domain>"
9031 # (The plain smtp:// proto is optional)
9032 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
9035 # Here is a pretty large one which does not allow sending mails
9036 # if there is a domain name mismatch on the SMTP protocol level,
9037 # which would bite us if the value of from does not match, e.g.,
9038 # for people who have a sXXXXeforge project and want to speak
9039 # with the mailing list under their project account (in from),
9040 # still sending the message through their normal mail provider
9042 set from="Your Name <youremail@domain>"
9043 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
9044 hostname=yaXXex.com smtp-hostname=
9047 # Create some new commands so that, e.g., `ls /tmp' will..
9058 ghost llS !ls -aFlrS
9061 # We don't support gpg(1) directly yet. But simple --clearsign'd
9062 # message parts can be dealt with as follows:
9065 set pipe-text/plain="@*#++=@\e
9066 < \e"${NAIL_FILENAME_TEMPORARY}\e" awk \e
9067 -v TMPFILE=\e"${NAIL_FILENAME_TEMPORARY}\e" '\e
9069 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
9072 print \e"--- GPG --verify ---\e";\e
9073 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
9074 print \e"--- GPG --verify ---\e";\e
9078 /^-----BEGIN PGP SIGNATURE-----/,\e
9079 /^-----END PGP SIGNATURE-----/ {\e
9089 !printf 'Key IDs to gpg --recv-keys: ';\e
9091 gpg --recv-keys ${keyids};
9097 When storing passwords in
9099 appropriate permissions should be set on this file with
9100 .Ql $ chmod 0600 \*(ur .
9103 is available user credentials can be stored in the central
9105 file instead; e.g., here is a different version of the example account
9106 that sets up SMTP and POP3:
9108 .Bd -literal -offset indent
9110 set from="Your Name <youremail@domain>"
9112 #set agent-shell-lookup="gpg -d .pass.gpg"
9114 set smtp=smtps://smtp.yXXXXx.ru:465 \e
9115 smtp-hostname= hostname=yXXXXx.com
9116 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
9117 ghost xp fi pop3s://pop.yXXXXx.ru
9126 .Bd -literal -offset indent
9127 machine *.yXXXXx.ru login USER password PASS
9132 .Va agent-shell-lookup
9133 is available things could be diversified further by using encrypted
9134 password storage: for this, don't specify
9138 file and instead uncomment the line that defines agent lookup in the
9141 above, then create the encrypted password storage file
9144 .Bd -literal -offset indent
9147 $ eval `gpg-agent --daemon \e
9148 --pinentry-program=/usr/bin/pinentry-curses \e
9149 --max-cache-ttl 99999 --default-cache-ttl 99999`
9153 This configuration should now work just fine (use the
9155 command line option for a(n almost) dry-run):
9158 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
9161 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
9162 .Ss "Signed and encrypted messages with S/MIME"
9164 \*(OP S/MIME provides two central mechanisms:
9165 message signing and message encryption.
9166 A signed message contains some data in addition to the regular text.
9167 The data can be used to verify that the message was sent using a valid
9168 certificate, that the sender's address in the message header matches
9169 that in the certificate, and that the message text has not been altered.
9170 Signing a message does not change its regular text;
9171 it can be read regardless of whether the recipient's software is able to
9175 It is thus usually possible to sign all outgoing messages if so desired.
9176 Encryption, in contrast, makes the message text invisible for all people
9177 except those who have access to the secret decryption key.
9178 To encrypt a message, the specific recipient's public encryption key
9180 It is therefore not possible to send encrypted mail to people unless their
9181 key has been retrieved from either previous communication or public key
9183 A message should always be signed before it is encrypted.
9184 Otherwise, it is still possible that the encrypted message text is
9188 A central concept to S/MIME is that of the certification authority (CA).
9189 A CA is a trusted institution that issues certificates.
9190 For each of these certificates it can be verified that it really
9191 originates from the CA, provided that the CA's own certificate is
9193 A set of CA certificates is usually delivered with OpenSSL and installed
9195 If you trust the source of your OpenSSL software installation,
9196 this offers reasonable security for S/MIME on the Internet.
9198 .Va ssl-no-default-ca
9202 .Va smime-ca-dir . )
9203 In general, a certificate cannot be more secure than the method its CA
9204 certificate has been retrieved with, though.
9205 Thus if you download a CA certificate from the Internet,
9206 you can only trust the messages you verify using that certificate as
9207 much as you trust the download process.
9210 The first thing you need for participating in S/MIME message exchange is
9211 your personal certificate, including a private key.
9212 The certificate contains public information, in particular your name and
9213 your email address(es), and the public key that is used by others to
9214 encrypt messages for you,
9215 and to verify signed messages they supposedly received from you.
9216 The certificate is included in each signed message you send.
9217 The private key must be kept secret.
9218 It is used to decrypt messages that were previously encrypted with your
9219 public key, and to sign messages.
9222 For personal use it is recommended that you get a S/MIME certificate
9223 from one of the major CAs on the Internet using your WWW browser.
9224 Many CAs offer such certificates for free.
9226 .Lk https://www.CAcert.org
9227 which issues client and server certificates to members of their
9228 community for free; their root certificate
9229 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9230 is often not in the default set of trusted CA root certificates, though,
9231 which means you will have to download their root certificate separately
9232 and ensure it is part of our S/MIME certificate validation chain by
9235 or as a vivid member of the
9237 But let's take a step-by-step tour on how to setup S/MIME with
9238 a certificate from CAcert.org despite this situation!
9241 First of all you will have to become a member of the CAcert.org
9242 community, simply by registrating yourself via the web interface.
9243 Once you are, create and verify all email addresses you want to be able
9244 to create signed and encrypted messages for/with using the corresponding
9245 entries of the web interface.
9246 Now ready to create S/MIME certificates, so let's create a new
9247 .Dq client certificate ,
9248 ensure to include all email addresses that should be covered by the
9249 certificate in the following web form, and also to use your name as the
9253 Create a private key and a certificate request on your local computer
9254 (please see the manual pages of the used commands for more in-depth
9255 knowledge on what the used arguments etc. do):
9258 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9261 Afterwards copy-and-paste the content of
9263 into the certificate-request (CSR) field of the web form on the
9264 CAcert.org website (you may need to unfold some
9265 .Dq advanced options
9266 to see the corresponding text field).
9267 This last step will ensure that your private key (which never left your
9268 box) and the certificate belong together (through the public key that
9269 will find its way into the certificate via the certificate-request).
9270 You are now ready and can create your CAcert certified certificate.
9271 Download and store or copy-and-paste it as
9276 In order to use your new S/MIME setup you will have to create
9277 a combined private key/public key (certificate) file:
9280 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9283 This is the file \*(UA will work with.
9284 If you have created your private key with a passphrase then \*(UA will
9285 ask you for it whenever a message is signed or decrypted.
9286 Set the following variables to henceforth use S/MIME (setting
9288 is of interest for verification only):
9290 .Bd -literal -offset indent
9291 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9292 smime-sign-cert=ME@HERE.com.paired \e
9293 smime-sign-message-digest=SHA256 \e
9298 From each signed message you send, the recipient can fetch your
9299 certificate and use it to send encrypted mail back to you.
9300 Accordingly if somebody sends you a signed message, you can do the same,
9303 command to check the validity of the certificate.
9306 Variables of interest for S/MIME signing:
9310 .Va smime-crl-file ,
9311 .Va smime-no-default-ca ,
9313 .Va smime-sign-cert ,
9314 .Va smime-sign-include-certs
9316 .Va smime-sign-message-digest .
9319 After it has been verified save the certificate via
9321 and tell \*(UA that it should use it for encryption for further
9322 communication with that somebody:
9324 .Bd -literal -offset indent
9326 set smime-encrypt-USER@HOST=FILENAME \e
9327 smime-cipher-USER@HOST=AES256
9331 Additional variables of interest for S/MIME en- and decryption:
9334 .Va smime-encrypt-USER@HOST .
9337 You should carefully consider if you prefer to store encrypted messages
9339 If you do, anybody who has access to your mail folders can read them,
9340 but if you do not, you might be unable to read them yourself later if
9341 you happen to lose your private key.
9344 command saves messages in decrypted form, while the
9348 commands leave them encrypted.
9351 Note that neither S/MIME signing nor encryption applies to message
9352 subjects or other header fields yet.
9353 Thus they may not contain sensitive information for encrypted messages,
9354 and cannot be trusted even if the message content has been verified.
9355 When sending signed messages,
9356 it is recommended to repeat any important header information in the
9360 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9361 .Ss "Using CRLs with S/MIME or SSL/TLS"
9363 \*(OP Certification authorities (CAs) issue certificate revocation
9364 lists (CRLs) on a regular basis.
9365 These lists contain the serial numbers of certificates that have been
9366 declared invalid after they have been issued.
9367 Such usually happens because the private key for the certificate has
9369 because the owner of the certificate has left the organization that is
9370 mentioned in the certificate, etc.
9371 To seriously use S/MIME or SSL/TLS verification,
9372 an up-to-date CRL is required for each trusted CA.
9373 There is otherwise no method to distinguish between valid and
9374 invalidated certificates.
9375 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9376 the Internet, so you have to retrieve them by some external mechanism.
9379 \*(UA accepts CRLs in PEM format only;
9380 CRLs in DER format must be converted, like, e.\|g.:
9383 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9386 To tell \*(UA about the CRLs, a directory that contains all CRL files
9387 (and no other files) must be created.
9392 variables, respectively, must then be set to point to that directory.
9393 After that, \*(UA requires a CRL to be present for each CA that is used
9394 to verify a certificate.
9397 .\" .Ss "Handling spam" {{{
9400 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9401 identification of, and, in general, dealing with spam messages.
9402 A precondition of most commands in order to function is that the
9404 variable is set to one of the supported interfaces.
9405 Once messages have been identified as spam their (volatile)
9407 state can be prompted: the
9411 message specifications will address respective messages and their
9413 entries will be used when displaying the
9415 in the header display.
9420 rates the given messages and sets their
9423 If the spam interface offers spam scores those can also be displayed in
9424 the header display by including the
9434 will interact with the Bayesian filter of the chosen interface and learn
9435 the given messages as
9439 respectively; the last command can be used to cause
9441 of messages; it adheres to their current
9443 state and thus reverts previous teachings.
9448 will simply set and clear, respectively, the mentioned volatile
9450 message flag, without any interface interaction.
9457 .Va spam-interface Ns s
9461 require a running instance of the
9463 server in order to function, started with the option
9465 shall Bayesian filter learning be possible.
9467 only works via a local path-based
9469 socket, but otherwise the following will be equivalently fine:
9471 .Bd -literal -offset indent
9472 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9473 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9474 --daemonize [--local] [--allow-tell]
9478 Thereafter \*(UA can make use of these interfaces:
9480 .Bd -literal -offset indent
9481 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9482 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9484 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9485 -Sspamc-command=/usr/local/bin/spamc \e
9486 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9488 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9489 -Sspamc-command=/usr/local/bin/spamc \e
9490 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9494 Using the generic filter approach allows usage of programs like
9498 Here is an example for the former, requiring it to be accessible via
9501 .Bd -literal -offset indent
9502 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
9503 -Sspamfilter-ham="bogofilter -n" \e
9504 -Sspamfilter-noham="bogofilter -N" \e
9505 -Sspamfilter-nospam="bogofilter -S" \e
9506 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9507 -Sspamfilter-spam="bogofilter -s" \e
9508 -Sspamfilter-rate-scanscore="1;^(.+)$"
9512 Because messages must exist on local storage in order to be scored (or
9513 used for Bayesian filter training), it is possibly a good idea to
9514 perform the local spam check last:
9516 .Bd -literal -offset indent
9517 define spamdelhook {
9519 spamset (header x-dcc-brand-metrics "bulk")
9520 # Server-side spamassassin(1)
9521 spamset (header x-spam-flag "YES")
9522 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9528 set folder-hook-FOLDER=spamdelhook
9532 See also the documentation for the variables
9533 .Va spam-interface , spam-maxsize ,
9534 .Va spamc-command , spamc-arguments , spamc-user ,
9535 .Va spamd-socket , spamd-user ,
9536 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9539 .Va spamfilter-rate-scanscore .
9547 .\" .Ss "\*(UA shortly hangs on startup" {{{
9548 .Ss "\*(UA shortly hangs on startup"
9550 This can have two reasons, one is the necessity to wait for a file lock
9551 and can't be helped, the other being that \*(UA calls the function
9553 in order to query the nodename of the box (sometimes the real one is
9554 needed instead of the one represented by the internal variable
9556 You may have varying success by ensuring that the real hostname and
9560 or, more generally, that the name service is properly setup \(en
9563 return what you'd expect?
9564 Does this local hostname has a domain suffix?
9565 RFC 6762 standardized the link-local top-level domain
9569 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9570 .Ss "I can't login to Google mail a.k.a. GMail"
9572 Since 2014 some free service providers classify programs as
9574 unless they use a special authentification method (OAuth 2.0) which
9575 wasn't standardized for non-HTTP protocol authentication token query
9576 until August 2015 (RFC 7628).
9579 Different to Kerberos / GSSAPI, which is developed since the mid of the
9580 1980s, where a user can easily create a local authentication ticket for
9581 her- and himself with the locally installed
9583 program, that protocol has no such local part but instead requires
9584 a world-wide-web query to create or fetch a token; since there is no
9585 local cache this query has to be performed whenever \*(UA is invoked
9586 from the command line (in interactive sessions situation may differ).
9589 \*(UA doesn't support OAuth.
9590 Because of this it is necessary to declare \*(UA a
9592 (on the providers account web page) in order to read and send mail.
9593 However, it also seems possible to take the following steps instead:
9598 give the provider the number of a mobile phone,
9601 .Dq 2-Step Verification ,
9603 create an application specific password (16 characters), and
9605 use that special password instead of your real Google account password in
9606 S-nail (for more on that see the section
9607 .Sx "On URL syntax and credential lookup" ) .
9613 .\" .Sh "SEE ALSO" {{{
9631 .Xr spamassassin 1 ,
9657 M. Douglas McIlroy writes in his article
9658 .Dq A Research UNIX Reader: Annotated Excerpts \
9659 from the Programmer's Manual, 1971-1986
9662 command already appeared in First Edition
9666 .Bd -ragged -offset indent
9667 Electronic mail was there from the start.
9668 Never satisfied with its exact behavior, everybody touched it at one
9669 time or another: to assure the safety of simultaneous access, to improve
9670 privacy, to survive crashes, to exploit uucp, to screen out foreign
9671 freeloaders, or whatever.
9672 Not until v7 did the interface change (Thompson).
9673 Later, as mail became global in its reach, Dave Presotto took charge and
9674 brought order to communications with a grab-bag of external networks
9680 Mail was written in 1978 by Kurt Shoens and developed as part of the
9683 distribution until 1995.
9684 Mail has then seen further development in open source
9686 variants, noticeably by Christos Zoulas in
9688 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9689 Ritter in the years 2000 until 2008.
9690 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9691 This man page is derived from
9692 .Dq The Mail Reference Manual
9693 that was originally written by Kurt Shoens.
9700 .An "Christos Zoulas" ,
9701 .An "Gunnar Ritter" ,
9702 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9704 .Mt s-mailx@sdaoden.eu ) .
9710 The character set conversion uses and relies upon the
9713 Its functionality differs widely between the various system environments
9717 Limitations with POP3 mailboxes are:
9718 It is not possible to edit messages, they can only be copied and deleted.
9719 The line count for the header display is only appropriate if the entire
9720 message has been downloaded from the server.
9721 The status field of a message is maintained by the server between
9722 connections; some servers do not update it at all, and with a server
9725 command will not cause the message status to be reset.
9730 variable have no effect.
9731 It is not possible to rename or to remove POP3 mailboxes.
9738 is typed while a POP3 operation is in progress, \*(UA will wait
9739 until the operation can be safely aborted, and will then return to the
9740 command loop and print the prompt again.
9743 is typed while \*(UA is waiting for the operation to complete, the
9744 operation itself will be cancelled.
9745 In this case, data that has not been fetched yet will have to be fetched
9746 before the next command can be performed.
9747 If the cancelled operation was using an SSL/TLS encrypted channel,
9748 an error in the SSL transport will very likely result and render the
9749 connection unusable.
9752 As \*(UA is a mail user agent, it provides only basic SMTP services.
9753 If it fails to contact its upstream SMTP server, it will not make
9754 further attempts to transfer the message at a later time,
9755 and it does not leave other information about this condition than an
9756 error message on the terminal and an entry in
9758 This is usually not a problem if the SMTP server is located in the same
9759 local network as the computer on which \*(UA is run.
9760 However, care should be taken when using a remote server of an ISP;
9761 it might be better to set up a local SMTP server then which just acts as
9765 \*(UA immediately contacts the SMTP server (or
9767 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9768 servers usually provide much more elaborated delay handling than \*(UA
9769 could perform as a client.
9777 from the distribution or the repository.
9779 After deleting some message of a POP3 mailbox the header summary falsely
9780 claims that there are no messages to display, you need to perform
9781 a scroll or dot movement to restore proper state.
9783 In threaded display a power user may encounter crashes very
9784 occasionally (this is may and very).