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
26 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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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]
56 .ds NQ [Only new quoting rules]
67 .Nd send and receive Internet mail
80 .Op Fl a Ar attachment
83 .Op Fl q Ar quote-file
85 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
90 .Op Fl Fl \~ Ns Ar mta-option ...
99 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
102 .Op Fl Fl \~ Ns Ar mta-option ...
110 .Op Fl L Ar spec-list
111 .Op Fl r Ar from-addr
112 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
115 .Op Fl Fl \~ Ns Ar mta-option ...
120 .Mx -toc -tree html pdf ps xhtml
123 .\" .Sh DESCRIPTION {{{
126 .Bd -filled -compact -offset indent
127 .Sy Compatibility note:
128 S-nail (\*(UA) will wrap up into \%S-mailx in v15.0 (circa 2018).
129 Backward incompatibility has to be expected \(en
133 -style argument quoting rules, for example.
134 New and old behaviour is flagged \*(IN and \*(OU, and setting
137 .Sx "INTERNAL VARIABLES" ,
138 will choose new behaviour when applicable.
139 \*(OB flags what will vanish, and enabling
143 enables obsoletion warnings.
147 \*(UA is a mail processing system with a command syntax reminiscent of
149 with lines replaced by messages.
150 It is intended to provide the functionality of the POSIX
152 command, but is MIME capable and optionally offers extensions for
153 line editing, S/MIME, SMTP and POP3 among others.
154 It is usable as a mail batch language.
156 .\" .Ss "Options" {{{
159 .Bl -tag -width ".Fl _ Ar _ccount"
162 Explicitly control which of the
164 shall be loaded: if the letter
166 is (case-insensitively) part of the
170 is loaded, likewise the letter
172 controls loading of the user's personal
174 file, whereas the letters
178 explicitly forbid loading of any resource files.
179 This option should be used by scripts: to avoid environmental noise they
182 from any configuration files and create a script-local environment,
183 explicitly setting any of the desired
184 .Sx "INTERNAL VARIABLES"
187 This option overrides
194 command for the given user email
196 after program startup is complete.
197 Being a special incarnation of
199 macros for the purpose of bundling longer-lived settings, activating
200 such an email account also switches to the accounts
206 Attach the given file to the message.
207 The same filename conventions as described in the section
209 apply: shell word expansion is restricted to the tilde
213 not be accessible but contain a
215 character, then anything after the
217 is assumed to specify the input character set and anything before
219 the filename: this is the only option to specify the input character set
220 (and don't perform any character set conversion) for text attachments
221 from the command line, not using the
223 tilde escape command.
227 Make standard input and standard output line-buffered.
231 Send a blind carbon copy to
233 Can be used multiple times, but it is also possible to give
234 a comma-separated list of receivers in a single argument, proper shell
235 quoting provided, e.g.,
236 .Ql -b """qrec1 , rec2,rec3, Ex <am@ple>""" .
238 .Sx "On sending mail, and non-interactive mode" .
242 Send carbon copies to the given receiver(s).
243 Can be used multiple times.
249 variable which enables debug messages and disables message delivery,
250 among others; effectively turns almost any operation into a dry-run.
256 variable and thus discard messages with an empty message part body.
257 This is useful for sending messages from scripts.
261 Just check if mail is present (in the specified or system
263 box): if yes, return an exit status of zero, a non-zero value otherwise.
264 To restrict the set of mails to consider in this evaluation a message
265 specification can be added with the option
270 Save the message to send in a file named after the local part of the
271 first recipient's address (instead of in
276 Read in the contents of the user's
278 (or the specified file) for processing;
279 when \*(UA is quit, it writes undeleted messages back to this file
283 Some special conventions are recognized for the string
285 which are documented for the
290 is not a direct argument to the flag
292 but is instead taken from the command line after option processing has
296 that starts with a hyphen, prefix it with a (relative) path, as in
297 .Ql ./-hyphenbox.mbox .
301 Display a summary of the
303 of all messages in the specified or system
306 A configurable summary view is available via the
312 Show a short usage summary.
313 Because of widespread use a
315 argument will have the same effect.
321 variable to ignore tty interrupt signals.
324 .It Fl L Ar spec-list
325 Display a summary of all
327 of only those messages in the specified or system
329 box that match the given
333 .Sx "Specifying messages"
340 option has been given in addition no header summary is produced,
341 but \*(UA will instead indicate via its exit status wether
347 note that any verbose output is suppressed in this mode and must instead
348 be enabled explicitly (e.g., by using the option
355 variable and thus inhibit initial display of message headers when
356 reading mail or editing a mail folder.
360 Standard flag that inhibits reading the system wide
365 allows more control over the startup sequence; also see
366 .Sx "Resource files" .
370 Initialize the message body with the contents of the specified file,
371 which may be standard input
373 only in non-interactive context.
374 May be given in send mode only.
378 Any folder opened will be in read-only mode.
384 is a valid address then it specifies the envelope sender address to be
387 when a message is send.
390 include a user name, then the address components will be separated and
391 the name part will be passed to the MTA individually via
395 will also be assigned to the
398 .Ql -Sfrom=address ) ,
399 therefore affecting possible SMTP data transfer;
400 note this assignment does not cause value fixation.
402 If instead an empty string is passed as
404 then the content of the variable
406 will be evaluated and used for this purpose whenever the MTA is
408 Note that \*(UA by default, without
410 that is, neither passes
414 flags to the MTA by itself.
417 .It Fl S Ar variable Ns Op = Ns value
420 and, in case of a value variable, assigns
423 Even though variables (see
424 .Sx "INTERNAL VARIABLES" )
428 may be overwritten from within resource files,
429 the command line setting will be reestablished after all resource files
434 Specify the subject of the to-be-sent message.
438 The message given (on standard input) is expected to contain, separated
439 from the message body with an empty line, a message header with
444 fields giving its recipients, which will be added to those given on the
446 If a message subject is specified via
448 then it'll be used in favour of one given on the command line.
457 Note you can also specify
461 and the envelope address possibly specified with the option
464 The following, which are normally created automatically based
465 upon the message context, can also be specified:
470 .Ql Mail-Followup-To:
471 (special address massage will however still occur for the latter).
472 In fact custom header fields may also be used, the content of which
473 is passed through unchanged.
477 can be embedded, too.
481 Initially read the primary system mailbox of
483 appropriate privileges presumed; effectively identical to
488 Show \*(UA's version and exit.
494 variable enables display of some informational context messages.
495 Using it twice increases the level of verbosity.
501 to the list of commands to be executed before normal operation starts.
505 .Va batch-exit-on-error ;
506 the only possibility to execute commands in non-interactive mode when
507 reading startup files is actively prohibited.
513 even if not in interactive mode.
514 This can be used to, e.g., automatically format the composed message
515 text before sending the message:
516 .Bd -literal -offset indent
517 $ ( echo 'line one. Word. Word2.'; \e
518 echo '~| /usr/bin/fmt -tuw66' ) |\e
519 LC_ALL=C \*(uA -:/ -d~ bob@exam.ple
525 In batch mode the full set of commands is available, just like in
526 interactive mode, and diverse variable settings and internal states are
527 adjusted for batch necessities, e.g., it sets
538 also no initial header listing will be printed, and processing of
540 is enabled in compose mode.
541 The following prepares an email message in a batched dry run:
542 .Bd -literal -offset indent
543 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en~.\enx\en' | \e
544 LC_ALL=C \*(uA -:/ -d#
549 This flag forces termination of option processing in order to prevent
552 It also forcefully puts \*(UA into send mode, see
553 .Sx "On sending mail, and non-interactive mode" .
557 In the above list of supported command line options,
561 are implemented by means of setting the respective option, as via
564 .Op Ar mta-option ...
566 arguments that are given at the end of the command line after a
568 separator will be passed through to the mail-transfer-agent (MTA) and
569 persist for an entire (interactive) session \(en if the setting of
571 allows their recognition;
572 MTA arguments can also be specified in the variable
573 .Va sendmail-arguments ;
574 find MTA interaction described in more detail in the documentation of
576 MTA arguments are ignored when mail is send via SMTP data transfer.
579 .\" .Ss "A starter" {{{
582 \*(UA is a direct descendant of
584 Mail, a successor of the Research
587 .Dq was there from the start
592 Mail reference manual begins with the following words:
594 .Bd -ragged -offset indent
595 Mail provides a simple and friendly environment for sending and
597 It divides incoming mail into its constituent messages and allows the
598 user to deal with them in any order.
599 In addition, it provides a set of
601 -like commands for manipulating messages and sending mail.
602 Mail offers the user simple editing capabilities to ease the composition
603 of outgoing messages, as well as providing the ability to define and
604 send to names which address groups of users.
608 \*(UA is thus the user side of the
610 mail system, whereas the system side (mail-transfer-agent, MTA) was
611 traditionally taken by
617 are often used for this purpose instead.
618 If the \*(OPal SMTP is included in the
620 of \*(UA then the system side is not a mandatory precondition for mail
624 Because \*(UA strives for compliance with POSIX
626 it is likely that some configuration settings have to be adjusted before
627 using it is a smooth experience.
630 file already bends those standard settings a bit towards more user
631 friendliness and safety, e.g., it sets the
635 variables in order to suppress the automatic moving of messages to
637 that would otherwise occur (see
638 .Sx "Message states" )
641 to not remove empty files in order not to mangle file permissions when
642 files eventually get recreated.
645 option so that by default file grouping (via the
647 prefix as documented also for
652 contains some further suggestions.
655 .\" .Ss "On sending mail, and non-interactive mode" {{{
656 .Ss "On sending mail, and non-interactive mode"
658 To send a message to one or more people, using a local
659 mail-transfer-agent (MTA; the executable path can be set via
661 or the \*(OPal builtin SMTP (set and see the variable
663 transport to actually deliver the generated mail message, \*(UA can be
664 invoked with arguments which are the names of people to whom the mail
665 will be sent, and the command line options
669 can be used to add (blind) carbon copy receivers:
671 .Bd -literal -offset indent
672 $ \*(uA -s ubject -a ttach.txt bill@exam.ple
673 # But... try it in an isolated dry-run mode first
674 $ LC_ALL=C \*(uA -:/ -d -vv -Ssendwait \e
675 -b bcc@exam.ple -c cc@exam.ple -s "A subject" -. \e
676 "(Lovely) Bob <bob@exam.ple>" eric@exam.ple
680 If standard input is a terminal rather than the message to be sent,
681 the user is expected to type in the message contents.
682 In this compose mode \*(UA treats lines beginning with the character
684 special \(en these are so-called
686 which can be used to read in files, process shell commands, add and edit
687 attachments and more; e.g., the tilde escape
689 will start the text editor to revise the message in it's current state,
691 allows editing of the most important message headers and
693 gives an overview of available tilde escapes.
697 at the beginning of an empty line leaves compose mode and causes the
698 message to be sent, whereas typing
701 twice will abort the current letter (saving its contents in the file
707 Messages are sent asynchronously unless the variable
709 is set, therefore send errors won't be reported.
715 .Sx "INTERNAL VARIABLES"
716 can be used to alter default behavior; e.g.,
721 will automatically startup a text editor when compose mode is entered,
723 will cause the user to be prompted actively for carbon-copy recipients
726 option will allow leaving compose mode by writing a line consisting
732 hook macros may be set to automatically adjust some settings dependend
733 on receiver, sender or subject contexts.
738 is often necessary (e.g., for
740 transfer), and saving a copy of sent messages in a
742 may be desirable \(en as for most mailbox file targets some special
743 syntax conventions are recognized (see the
745 command for more on that).
748 for the purpose of arranging a complete environment of settings that can
749 be switched to with a single command or command line option may be
752 contains example configurations for sending messages via some of the
753 well-known public mail providers and also gives a compact overview on
754 how to setup a secure SSL/TLS environment).
759 sandbox dry-run tests first will prove correctness.
763 .Sx "On URL syntax and credential lookup"
764 will spread light on the different ways of how to specify user email
765 account credentials, the
767 variable chains, and accessing protocol-specific resources,
770 goes into the details of character encoding and how to use them for
771 representing messages and MIME part contents by specifying them in
773 and reading the section
774 .Sx "The mime.types files"
775 should help to understand how the MIME-type of outgoing attachments are
776 classified, and what can be done for fine-tuning.
779 Message recipients (as specified on the command line or defined in
784 may not only be email addressees but can also be names of mailboxes and
785 even complete shell command pipe specifications.
788 is not set then only network addresses (see
790 for a description of mail addresses) and plain user names (including MTA
791 aliases) may be used, other types will be filtered out, giving a warning
794 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
795 .\" grep the latter for the complete picture
799 is set then extended recipient addresses will optionally be accepted:
800 Any name which starts with a vertical bar
802 character specifies a command pipe \(en the command string following the
804 is executed and the message is sent to its standard input;
805 Likewise, any name that starts with the character slash
807 or the character sequence dot slash
809 is treated as a file, regardless of the remaining content.
810 Any other name which contains an at sign
812 character is treated as a network address;
813 Any other name which starts with a plus sign
815 character specifies a mailbox name;
816 Any other name which contains a slash
818 character but no exclamation mark
822 character before also specifies a mailbox name;
823 What remains is treated as a network address.
825 .Bd -literal -offset indent
826 $ echo bla | \*(uA -Sexpandaddr -s test ./mbox.mbox
827 $ echo bla | \*(uA -Sexpandaddr -s test '|cat >> ./mbox.mbox'
828 $ echo safe | LC_ALL=C \e
829 \*(uA -:/ -Sv15-compat -Ssendwait -Snosave \e
830 -Sexpandaddr=fail,-all,+addr -s test \e
835 It is possible to create personal distribution lists via the
837 command, so that, for instance, the user can send mail to
839 and have it go to a group of people.
840 These aliases have nothing in common with the system wide aliases that
841 may be used by the MTA (mail-transfer-agent), which are subject to the
845 and are often tracked in a file
851 Personal aliases will be expanded by \*(UA before the message is sent,
852 and are thus a convenient alternative to specifying each addressee by
856 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
859 To avoid environmental noise scripts should
861 \*(UA from any configuration files and create a script-local
862 environment, ideally with the command line options
864 to disable any configuration file in conjunction with repititions of
866 to specify variables:
868 .Bd -literal -offset indent
870 \*(uA -:/ -Sv15-compat -Ssendwait -Snosave \e
871 -Sexpandaddr=fail,-all,+addr \e
872 -S 'smtp=smtps://mylogin@exam.ple:465' -Ssmtp-auth=login \e
873 -S 'from=scriptreply@exam.ple' \e
874 -s 'subject' -a attachment_file \e
875 -. "Recipient 1 <rec1@exam.ple>" rec2@exam.ple \e
880 In interactive mode, which is introduced in the next section, messages
881 can be sent by calling the
883 command with a list of recipient addresses \(em the semantics are
884 completely identical to non-interactive message sending, except that
885 it is likely necessary to separate recipient lists with commas:
887 .Bd -literal -offset indent
888 $ \*(uA -d -Squiet -Semptystart
889 "/var/spool/mail/user": 0 messages
890 ? mail "Recipient 1 <rec1@exam.ple>", rec2@exam.ple
891 ? # Will do the right thing (tm)
892 ? m rec1@exam.ple rec2@exam.ple
896 .\" .Ss "On reading mail, and interactive mode" {{{
897 .Ss "On reading mail, and interactive mode"
899 When invoked without addressees \*(UA enters interactive mode in which
901 When used like that the user's system
905 for an in-depth description of the different mailbox types that exist)
906 is read in and a one line header of each message therein is displayed.
907 The visual style of this summary of
909 can be adjusted through the variable
911 and the possible sorting criterion via
913 If the initially opened mailbox is empty \*(UA will instead exit
914 immediately (after displaying a message) unless the variable
923 will give a listing of all available commands and
925 will give a summary of some common ones.
926 If the \*(OPal documentation strings are available one can type
928 and see the actual expansion of
930 and what it's purpose is, i.e., commands can be abbreviated
931 (note that POSIX defines some abbreviations, so that the alphabetical
932 order of commands doesn't necessarily relate to the abbreviations; it is
933 possible to define overwrites with the
938 Messages are given numbers (starting at 1) which uniquely identify
939 messages; the current message \(en the
941 \(en will either be the first new message, or the first unread message,
942 or the first message of the mailbox; the option
944 will instead cause usage of the last message for this purpose.
949 ful of header summaries containing the
953 will display only the summaries of the given messages, defaulting to the
957 Messages can be displayed on the user's terminal with the
961 By default the current message
963 is displayed, but like with many other commands it is possible to give
964 a fancy message specification (see
965 .Sx "Specifying messages" ) ,
968 will display all unread messages,
973 will type the messages 1 and 5,
975 will type the messages 1 through 5, and
979 will display the last and the next message, respectively.
982 (a more substantial alias of the standard command
984 will display a header summary of the given message specification list
985 instead of their content, e.g., the following will search for subjects:
988 .Dl from """@Some subject to search for"""
991 In the default setup all header fields of a message will be displayed,
992 but this can be changed: either by blacklisting a list of fields via
994 or by whitelisting only a given list with the
997 .Ql Ic \:retain Ns \0date from to cc subject .
998 In order to display all header fields of a message regardless of
999 currently active ignore or retain lists, use the command
1003 controls wether and when \*(UA will use the configured
1005 for display instead of directly writing to the user terminal
1006 (generally speaking).
1007 Note that historically the global
1009 not only adjusts the list of displayed headers, but also sets
1013 Dependent upon the configuration a line editor (see the section
1014 .Sx "On terminal control and line editor" )
1015 aims at making user experience with the many
1018 When reading the system
1024 specified a mailbox explicitly prefixed with the special
1026 modifier (propagating the mailbox to a primary one) then messages which
1027 have been read will be moved to a secondary mailbox, the user's
1029 file, automatically when the mailbox is left, either by changing the
1030 active mailbox or by quitting \*(UA (also see
1031 .Sx "Message states" )
1032 \(en this automatic moving from a system or primary to the secondary
1033 mailbox is not performed when the variable
1038 After examining a message the user can also
1042 to the sender and all recipients or
1044 exclusively to the sender(s).
1045 Messages can also be
1047 ed (shorter alias is
1049 Note that when replying to or forwarding a message recipient addresses
1050 will be stripped from comments and names unless the option
1053 Deletion causes \*(UA to forget about the message;
1054 This is not irreversible, though, one can
1056 the message by giving its number,
1057 or the \*(UA session can be ended by giving the
1062 To end a mail processing session one may either issue
1064 to cause a full program exit, which possibly includes
1065 automatic moving of read messages to
1067 as well as updating the \*(OPal line editor
1071 instead in order to prevent any of these actions.
1074 .\" .Ss "HTML mail and MIME attachments" {{{
1075 .Ss "HTML mail and MIME attachments"
1077 Messages which are HTML-only get more and more common and of course many
1078 messages come bundled with a bouquet of MIME attachments.
1079 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1080 with HTML messages (see
1081 .Sx "The mime.types files" ) ,
1082 it normally can't deal with any of these itself, but instead programs
1083 need to become registered to deal with specific MIME types or file
1085 These programs may either prepare plain text versions of their input
1086 in order to enable \*(UA to display the content on the terminal,
1087 or display the content themselves, for example in a graphical window.
1090 To install an external handler program for a specific MIME type set an
1092 .Va pipe-TYPE/SUBTYPE
1093 variable; to instead define a handler for a specific file extension set
1096 variable \(en these handlers take precedence.
1097 \*(OPally \*(UA supports mail user agent configuration as defined in
1098 RFC 1524; this mechanism, documented in the section
1099 .Sx "The Mailcap files" ,
1100 will be queried for display or quote handlers if none of the former two
1101 .\" TODO v15-compat "will be" -> "is"
1102 did; it will be the sole source for handlers of other purpose.
1103 A last source for handlers may be the MIME type definition itself, if
1104 the \*(UA specific type-marker extension was used when defining the type
1107 (Many of the builtin MIME types do so by default.)
1111 .Va mime-counter-evidence
1112 can be set to improve dealing with faulty MIME part declarations as are
1113 often seen in real-life messages.
1114 E.g., to display a HTML message inline (that is, converted to a more
1115 fancy plain text representation than the builtin converter is capable to
1116 produce) with either of the text-mode browsers
1120 teach \*(UA about MathML documents and make it display them as plain
1121 text, and to open PDF attachments in an external PDF viewer,
1122 asynchronously and with some other magic attached:
1124 .Bd -literal -offset indent
1125 if $features !@ HTML-FILTER
1126 #set pipe-text/html='elinks -force-html -dump 1'
1127 set pipe-text/html='lynx -stdin -dump -force_html'
1128 # Display HTML as plain text instead
1129 #set pipe-text/html=@
1131 mimetype '@ application/mathml+xml mathml'
1132 wysh set pipe-application/pdf='@&=@ \e
1133 trap "rm -f \e"${NAIL_FILENAME_TEMPORARY}\e"" EXIT;\e
1134 trap "trap \e"\e" INT QUIT TERM; exit 1" INT QUIT TERM;\e
1135 mupdf "${NAIL_FILENAME_TEMPORARY}"'
1139 Note: special care must be taken when using such commands as mail
1140 viruses may be distributed by this method: if messages of type
1141 .Ql application/x-sh
1142 or files with the extension
1144 were blindly filtered through the shell, for example, a message sender
1145 could easily execute arbitrary code on the system \*(UA is running on.
1146 For more on MIME, also in respect to sending of messages, see the
1148 .Sx "The mime.types files" ,
1149 .Sx "The Mailcap files"
1154 .\" .Ss "Mailing lists" {{{
1157 \*(UA offers some support to ease handling of mailing lists.
1160 promotes all given arguments to known mailing lists, and
1162 sets their subscription attribute, creating them first as necessary.
1167 automatically, but only resets the subscription attribute.)
1168 Using the commands without arguments will show (a subset of) all
1169 currently defined mailing lists.
1174 can be used to mark out messages with configured list addresses
1175 in the header display.
1178 \*(OPally mailing lists may also be specified as (extended) regular
1179 expressions, which allows matching of many addresses with a single
1181 However, all fully qualified list addresses are matched via a fast
1182 dictionary, whereas expressions are placed in (a) list(s) which is
1183 (are) matched sequentially.
1185 .Bd -literal -offset indent
1186 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1187 wysh mlist a1@b1.c1 a2@b2.c2 '.*@lists\e.c3$'
1188 mlsubscribe a4@b4.c4 exact@lists.c3
1193 .Va followup-to-honour
1195 .Ql Mail-\:Followup-\:To:
1196 header is honoured when the message is being replied to (via
1202 controls wether this header is created when sending mails; it will be
1203 created automatically for a couple of reasons, too, like when the
1205 .Dq mailing list specific
1210 is used to respond to a message with its
1211 .Ql Mail-Followup-To:
1215 A difference in between the handling of known and subscribed lists is
1216 that the address of the sender is usually not part of a generated
1217 .Ql Mail-Followup-To:
1218 when addressing the latter, whereas it is for the former kind of lists.
1219 Usually because there are exceptions: say, if multiple lists are
1220 addressed and not all of them are subscribed lists.
1222 For convenience \*(UA will, temporarily, automatically add a list
1223 address that is presented in the
1225 header of a message that is being responded to to the list of known
1227 Shall that header have existed \*(UA will instead, dependend on the
1229 .Va reply-to-honour ,
1232 for this purpose in order to accept a list administrators' wish that
1233 is supposed to have been manifested like that (but only if it provides
1234 a single address which resides on the same domain as what is stated in
1238 .\" .Ss "Resource files" {{{
1239 .Ss "Resource files"
1241 Upon startup \*(UA reads in several resource files:
1243 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1246 System wide initialization file.
1247 Reading of this file can be suppressed, either by using the
1251 command line options, or by setting the
1254 .Ev NAIL_NO_SYSTEM_RC .
1258 File giving initial commands.
1259 A different file can be chosen by setting the
1263 Reading of this file can be suppressed with the
1265 command line option.
1267 .It Va NAIL_EXTRA_RC
1268 Can be used to define an optional startup file to be read after all
1269 other resource files.
1270 It can be used to specify settings that are not understood by other
1272 implementations, for example.
1273 This variable is only honoured when defined in a resource file, e.g.,
1275 .Sx "INTERNAL VARIABLES" .
1279 The content of these files is interpreted as follows:
1282 .Bl -bullet -compact
1284 A lines' leading whitespace is removed.
1286 Empty lines are ignored.
1288 Any other line is interpreted as a command.
1289 It may be spread over multiple input lines if the newline character is
1291 by placing a backslash character
1293 as the last character of the line; whereas any leading whitespace of
1294 follow lines is ignored, trailing whitespace before a escaped newline
1295 remains in the input.
1297 If the line (content) starts with the number sign
1299 then it is a comment-command \(en a real command! \(en and also ignored.
1300 This command is the only form of comment that is understood.
1304 Unless \*(UA is about to enter interactive mode syntax errors that occur
1305 while loading these files are treated as errors and cause program exit.
1306 More files with syntactically equal content can be
1308 The following, saved in a file, would be an examplary content:
1310 .Bd -literal -offset indent
1311 # This line is a comment command. And y\e
1312 es, it is really continued here.
1319 .\" .Ss "Character sets" {{{
1320 .Ss "Character sets"
1322 \*(OP \*(UA detects the character set of the terminal by using
1323 mechanisms that are controlled by the
1328 should give an overview); the \*(UA internal variable
1330 will be set to the detected terminal character set accordingly
1331 and will thus show up in the output of the commands
1337 However, a user supplied
1339 value is not overwritten by this detection mechanism: this
1341 must be used if the detection doesn't work properly,
1342 and it may be used to adjust the name of the locale character set.
1343 E.g., on BSD systems one may use a locale with the character set
1344 ISO8859-1, which is not a valid name for this character set; to be on
1345 the safe side, one may set
1347 to the correct name, which is ISO-8859-1.
1350 Note that changing the value doesn't mean much beside that,
1351 since several aspects of the real character set are implied by the
1352 locale environment of the system,
1353 and that stays unaffected by the content of an overwritten
1356 (This is mostly an issue when interactively using \*(UA, though.
1357 It is actually possible to send mail in a completely
1359 locale environment, an option that \*(UA's test-suite uses excessively.)
1362 If no character set conversion capabilities have been compiled into
1365 doesn't include the term
1369 will be the only supported character set,
1370 it is simply assumed that it can be used to exchange 8-bit messages,
1371 and the rest of this section does not apply;
1372 it may however still be necessary to explicitly set it if automatic
1373 detection fails, since in that case it defaults to the mentioned
1374 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1378 When reading messages, their text is converted into
1380 as necessary in order to display them on the users terminal.
1381 Unprintable characters and invalid byte sequences are detected
1382 and replaced by proper substitution characters (unless the variable
1384 was set once \*(UA was started).
1386 .Va charset-unknown-8bit
1387 to deal with another hairy aspect of message interpretation.
1390 When sending messages all their parts and attachments are classified.
1391 Whereas no character set conversion is performed on those parts which
1392 appear to be binary data,
1393 the character set being used must be declared within the MIME header of
1394 an outgoing text part if it contains characters that do not conform to
1395 the set of characters that are allowed by the email standards.
1396 Permissible values for character sets can be declared using the
1400 which defines a catch-all last-resort fallback character set that is
1401 implicitly appended to the list of character-sets in
1405 When replying to a message and the variable
1406 .Va reply-in-same-charset
1407 is set then the character set of the message being replied to is tried
1409 And it is also possible to make \*(UA work even more closely related to
1410 the current locale setting automatically by using the variable
1411 .Va sendcharsets-else-ttycharset ,
1412 please see there for more information.
1415 All the specified character sets are tried in order unless the
1416 conversion of the part or attachment succeeds.
1417 If none of the tried (8-bit) character sets is capable to represent the
1418 content of the part or attachment,
1419 then the message will not be sent and its text will optionally be
1423 In general, if the message
1424 .Dq Cannot convert from a to b
1425 appears, either some characters are not appropriate for the currently
1426 selected (terminal) character set,
1427 or the needed conversion is not supported by the system.
1428 In the first case, it is necessary to set an appropriate
1430 locale and/or the variable
1434 The best results are usually achieved when \*(UA is run in a UTF-8
1435 locale on a UTF-8 capable terminal, in which case the full Unicode
1436 spectrum of characters is available.
1437 In this setup characters from various countries can be displayed,
1438 while it is still possible to use more simple character sets for sending
1439 to retain maximum compatibility with older mail clients.
1442 On the other hand the POSIX standard defines a locale-independent 7-bit
1443 .Dq portable character set
1444 that should be used when overall portability is an issue, the even more
1445 restricted subset named
1446 .Dq portable filename character set
1447 consisting of A-Z, a-z, 0-9, period
1456 .\" .Ss "Message states" {{{
1457 .Ss "Message states"
1459 \*(UA differentiates in between several different message states;
1460 the current state will be reflected in header summary displays if
1462 is configured to do so (via the internal variable
1464 and messages can also be selected and be acted upon depending on their
1466 .Sx "Specifying messages" ) .
1467 When operating on the system
1469 box or in primary mailboxes opened with the special prefix
1473 special actions, like the automatic moving of messages to the secondary
1475 mailbox may be applied when the mailbox is left (also implicitly via
1476 a successful exit of \*(UA, but not if the special command
1478 is used) \(en however, because this may be irritating to users which
1481 mail-user-agents, the default global
1487 variables in order to suppress this behaviour.
1489 .Bl -tag -width ".It Ql _reserved"
1491 Message has neither been viewed nor moved to any other state.
1492 Such messages are retained even in the primary system mailbox.
1495 Message has neither been viewed nor moved to any other state, but the
1496 message was present already when the mailbox has been opened last:
1497 Such messages are retained even in the primary system mailbox.
1500 The message has been processed by one of the following commands:
1520 commands may also cause the next message to be marked as read, depending
1526 command is used, messages that are in the primary system mailbox or in
1527 mailboxes which were opened with the special
1531 state when the mailbox is left will be saved in
1538 The message has been processed by one of the following commands:
1544 can be used to access such messages.
1547 The message has been processed by a
1549 command and it will be retained in its current location.
1552 The message has been processed by one of the following commands:
1558 command is used, messages that are in the primary system mailbox or in
1559 mailboxes which were opened with the special
1563 state when the mailbox is left will be deleted; they will be saved in
1571 .\" .Ss "Specifying messages" {{{
1572 .Ss "Specifying messages"
1579 can be given a list of message numbers as arguments to apply to a number
1580 of messages at once.
1583 deletes messages 1 and 2,
1586 will delete the messages 1 through 5.
1587 In sorted or threaded mode (see the
1591 will delete the messages that are located between (and including)
1592 messages 1 through 5 in the sorted/threaded order, as shown in the
1595 Multiple colon modifiers can be joined into one, e.g.,
1597 The following special message names exist:
1599 .Bl -tag -width ".It Ar _n_u"
1605 All old messages (any not in state
1630 All answered messages
1635 All messages marked as draft.
1637 \*(OP All messages classified as spam.
1639 \*(OP All messages with unsure spam classification.
1641 The current message, the so-called
1644 The message that was previously the current message.
1646 The parent message of the current message,
1647 that is the message with the Message-ID given in the
1649 field or the last entry of the
1651 field of the current message.
1653 The next previous undeleted message,
1654 or the next previous deleted message for the
1657 In sorted/threaded mode,
1658 the next previous such message in the sorted/threaded order.
1660 The next undeleted message,
1661 or the next deleted message for the
1664 In sorted/threaded mode,
1665 the next such message in the sorted/threaded order.
1667 The first undeleted message,
1668 or the first deleted message for the
1671 In sorted/threaded mode,
1672 the first such message in the sorted/threaded order.
1675 In sorted/threaded mode,
1676 the last message in the sorted/threaded order.
1680 selects the message addressed with
1684 is any other message specification,
1685 and all messages from the thread that begins at it.
1686 Otherwise it is identical to
1691 the thread beginning with the current message is selected.
1696 All messages that were included in the message list for the previous
1699 .It Ar / Ns Ar string
1700 All messages that contain
1702 in the subject field (case ignored).
1709 the string from the previous specification of that type is used again.
1711 .It Xo Op Ar @ Ns Ar name-list Ns
1714 All messages that contain the given case-insensitive search
1716 ession; if the \*(OPal regular expression (see
1718 support is available
1720 will be interpreted as (an extended) one if any of the
1722 (extended) regular expression characters is seen.
1724 .Ar @ Ns Ar name-list
1725 part is missing, the search is restricted to the subject field body,
1728 specifies a comma-separated list of header fields to search, as in
1730 .Dl '@to,from,cc@Someone i ought to know'
1732 In order to search for a string that includes a
1734 (commercial at) character the
1736 is effectively non-optional, but may be given as the empty string.
1737 Some special header fields may be abbreviated:
1751 respectively and case-insensitively.
1756 can be used to search in (all of) the header(s) of the message, and the
1765 can be used to perform full text searches \(en whereas the former
1766 searches only the body, the latter also searches the message header.
1768 This message specification performs full text comparison, but even with
1769 regular expression support it is almost impossible to write a search
1770 expression that savely matches only a specific address domain.
1771 To request that the content of the header is treated as a list of
1772 addresses, and to strip those down to the plain email address which the
1773 search expression is to be matched against, prefix the header name
1774 (abbreviation) with a tilde
1777 .Dl @~f@@a\e.safe\e.domain\e.match$
1781 .Dq any substring matches
1784 header, which will match addresses (too) even if
1786 is set (and POSIX says
1787 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1790 variable is set, only the local part of the address is evaluated
1791 for the comparison, not ignoring case, and the setting of
1793 is completely ignored.
1794 For finer control and match boundaries use the
1796 search expression; the \*(OPal IMAP-style
1798 expression can also be used if substring matches are desired.
1802 \*(OP IMAP-style SEARCH expressions may also be used.
1803 This addressing mode is available with all types of folders;
1804 \*(UA will perform the search locally as necessary.
1805 Strings must be enclosed by double quotes
1807 in their entirety if they contain white space or parentheses;
1808 within the quotes, only backslash
1810 is recognized as an escape character.
1811 All string searches are case-insensitive.
1812 When the description indicates that the
1814 representation of an address field is used,
1815 this means that the search string is checked against both a list
1818 .Bd -literal -offset indent
1819 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1824 and the addresses without real names from the respective header field.
1825 These search expressions can be nested using parentheses, see below for
1829 .Bl -tag -compact -width ".It Ar _n_u"
1830 .It Ar ( criterion )
1831 All messages that satisfy the given
1833 .It Ar ( criterion1 criterion2 ... criterionN )
1834 All messages that satisfy all of the given criteria.
1836 .It Ar ( or criterion1 criterion2 )
1837 All messages that satisfy either
1842 To connect more than two criteria using
1844 specifications have to be nested using additional parentheses,
1846 .Ql (or a (or b c)) ,
1850 .Ql ((a or b) and c) .
1853 operation of independent criteria on the lowest nesting level,
1854 it is possible to achieve similar effects by using three separate
1858 .It Ar ( not criterion )
1859 All messages that do not satisfy
1861 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1862 All messages that contain
1864 in the envelope representation of the
1867 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1868 All messages that contain
1870 in the envelope representation of the
1873 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1874 All messages that contain
1876 in the envelope representation of the
1879 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1880 All messages that contain
1885 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1886 All messages that contain
1888 in the envelope representation of the
1891 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1892 All messages that contain
1897 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1898 All messages that contain
1901 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1902 All messages that contain
1904 in their header or body.
1905 .It Ar ( larger size )
1906 All messages that are larger than
1909 .It Ar ( smaller size )
1910 All messages that are smaller than
1914 .It Ar ( before date )
1915 All messages that were received before
1917 which must be in the form
1921 denotes the day of the month as one or two digits,
1923 is the name of the month \(en one of
1924 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1927 is the year as four digits, e.g.,
1931 All messages that were received on the specified date.
1932 .It Ar ( since date )
1933 All messages that were received since the specified date.
1934 .It Ar ( sentbefore date )
1935 All messages that were sent on the specified date.
1936 .It Ar ( senton date )
1937 All messages that were sent on the specified date.
1938 .It Ar ( sentsince date )
1939 All messages that were sent since the specified date.
1941 The same criterion as for the previous search.
1942 This specification cannot be used as part of another criterion.
1943 If the previous command line contained more than one independent
1944 criterion then the last of those criteria is used.
1948 .\" .Ss "On URL syntax and credential lookup" {{{
1949 .Ss "On URL syntax and credential lookup"
1951 \*(IN For accessing protocol-specific resources usage of Uniform
1952 Resource Locators (URL, RFC 1738) has become omnipresent.
1953 \*(UA expects and understands URLs in the following form;
1956 denote optional parts, optional either because there also exist other
1957 ways to define the information in question or because support of the
1958 part is protocol-specific (e.g.,
1960 is used by the IMAP protocol but not by POP3);
1965 are specified they must be given in URL percent encoded form (RFC 3986;
1973 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1976 Note that these \*(UA URLs most often don't conform to any real
1977 standard, but instead represent a normalized variant of RFC 1738 \(en
1978 they are not used in data exchange but only ment as a compact,
1979 easy-to-use way of defining and representing information in
1980 a well-known notation.
1983 Many internal variables of \*(UA exist in multiple versions, called
1984 variable chains for the rest of this document: the plain
1989 .Ql variable-USER@HOST .
1996 had been specified in the respective URL, otherwise it refers to the plain
2002 that had been found when doing the user chain lookup as is described
2005 will never be in URL percent encoded form, wether it came from an URL or
2006 not; i.e., values of
2007 .Sx "INTERNAL VARIABLES"
2008 must not be URL percent encoded.
2011 For example, wether an hypothetical URL
2012 .Ql smtp://hey%3Ayou@our.house
2013 had been given that includes a user, or wether the URL was
2014 .Ql smtp://our.house
2015 and the user had been found differently, to lookup the variable chain
2016 .Va smtp-use-starttls
2017 \*(UA first looks for wether
2018 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
2019 is defined, then wether
2020 .Ql smtp-\:use-\:starttls-\:our.house
2021 exists before finally ending up looking at the plain variable itself.
2024 \*(UA obeys the following logic scheme when dealing with the
2025 necessary credential informations of an account:
2031 has been given in the URL the variables
2035 are looked up; if no such variable(s) can be found then \*(UA will,
2036 when enforced by the \*(OPal variables
2037 .Va netrc-lookup-HOST
2044 specific entry which provides a
2046 name: this lookup will only succeed if unambiguous (one possible matching
2050 If there is still no
2052 then \*(UA will fall back to the user who is supposed to run \*(UA,
2053 the identity of which has been fixated during \*(UA startup and is
2054 known to be a valid user on the current host.
2057 Authentication: unless otherwise noted this will lookup the
2058 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
2059 variable chain, falling back to a protocol-specific default should this
2065 has been given in the URL, then if the
2067 has been found through the \*(OPal
2069 then that may have already provided the password, too.
2070 Otherwise the variable chain
2071 .Va password-USER@HOST , password-HOST , password
2072 is looked up and used if existent.
2074 \*(OP Then if any of the variables of the chain
2075 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2077 is set the shell command specified therein is run and the output (less
2078 newline characters) will be used as the password.
2079 It is perfectly valid for such an agent to simply not return any data,
2080 in which case the password lookup is continued somewhere else;
2081 Any command failure is treated as a hard error, however.
2083 Afterwards the complete \*(OPal variable chain
2084 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2088 cache is searched for a password only (multiple user accounts for
2089 a single machine may exist as well as a fallback entry without user
2090 but with a password).
2092 If at that point there is still no password available, but the
2093 (protocols') chosen authentication type requires a password, then in
2094 interactive mode the user will be prompted on the terminal.
2099 S/MIME verification works relative to the values found in the
2103 header field(s), which means that the values of
2104 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2106 .Va smime-sign-message-digest
2107 will not be looked up using the
2111 chains from above but instead use the corresponding values from the
2112 message that is being worked on.
2113 In unusual cases multiple and different
2117 combinations may therefore be involved \(en on the other hand those
2118 unusual cases become possible.
2119 The usual case is as short as:
2122 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2123 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2128 contains complete example configurations.
2131 .\" .Ss "On terminal control and line editor" {{{
2132 .Ss "On terminal control and line editor"
2134 \*(OP \*(UA can be configured to support a line editor,
2135 history lists that can be saved in between sessions,
2136 and terminal control to improve interactive usage experience.
2137 For the former one may either link against an external library
2138 .Pf ( Xr readline 3 ;
2139 behaviour of \*(UA may differ slightly),
2140 or enable the builtin Mailx-Line-Editor (MLE), which should work in all
2141 environments which comply to the ISO C standard
2143 and which will support wide glyphs if possible (the necessary
2144 functionality had been removed from ISO C, but was included in
2146 Prevent usage of a line editor in interactive mode by setting the
2148 .Va line-editor-disable .
2153 feature is available then input from line editor prompts will be saved
2154 in a history list that can be searched in and be expanded from.
2155 Such saving can be prevented by prefixing input with any amount of
2157 Aspects of history, like allowed content, maximum size etc., can be
2158 configured with the variables
2161 .Va history-gabby-persist
2166 \*(OP Terminal control will be realized through one of the standard
2168 libraries, either the
2170 or, alternatively, the
2172 both of which will be initialized to work with the environment variable
2174 Terminal control will enhance or enable interactive usage aspects, e.g.,
2175 .Sx "Coloured display" ,
2176 and extend behaviour of the MLE, which may learn the key-sequences of
2177 keys like the cursor and function keys, and which will automatically
2180 alternative screen shall the terminal support it.
2181 The internal variable
2183 can be used to overwrite settings or to learn (correct(ed)) keycodes.
2184 Actual interaction with the chosen library can be disabled completely by
2185 setting the internal variable
2186 .Va termcap-disable ,
2187 which may be necessary for proper operation on the actual terminal;
2189 will be queried regardless, even if the \*(OPal support for the
2190 libraries has not been enabled at configuration time.
2193 \*(OP The builtin \*(UA line editor MLE supports the following
2194 operations; the notation
2196 stands for the combination of the
2198 key plus the mentioned character, e.g.,
2201 .Dq hold down control key and press the A key .
2202 Especially without termcap support setting respective entries in
2204 will help shall the MLE misbehave.
2205 The MLE also supports several
2210 .Bl -tag -compact -width "Ql _M"
2212 Go to the start of the line.
2214 Move the cursor backward one character.
2216 Forward delete the character under the cursor;
2217 quits \*(UA if used on the empty line unless the
2221 Go to the end of the line.
2223 Move the cursor forward one character.
2226 Cancel current operation, full reset.
2227 If there is an active history search or tabulator expansion then this
2228 command will first reset that, reverting to the former line content;
2229 thus a second reset is needed for a full reset in this case.
2230 In all cases \*(UA will reset a possibly used multibyte character input
2236 backward delete one character.
2240 .Dq horizontal tabulator :
2241 try to expand the word before the cursor, also supporting \*(UA
2248 complete this line of input.
2250 Delete all characters from the cursor to the end of the line.
2254 \*(OP Go to the next history entry.
2259 \*(OP Go to the previous history entry.
2261 \*(OP Complete the current line from (the remaining older) history entries.
2268 Prompts for a Unicode character to be inserted.
2270 Delete the characters from the one preceding the cursor to the preceding
2273 Move the cursor forward one word boundary.
2275 Move the cursor backward one word boundary.
2279 If the keycodes are known then the left and right cursor keys will map to
2283 respectively, the up and down cursor keys will map to
2287 and the Home/End/PgUp/PgDown keys will call the
2289 command with the respective arguments
2295 (i.e., perform scrolling through the header summary list).
2296 Also the up and down cursor keys should invoke
2298 for up- and downwards movement if they are used while the
2303 .\" .Ss "Coloured display" {{{
2304 .Ss "Coloured display"
2306 \*(OP \*(UA can be configured to support a coloured display and font
2307 attributes by emitting ANSI / ISO 6429 SGR (select graphic rendition)
2309 Usage of colours and font attributes solely depends upon the
2310 capability of the detected terminal type that is defined by the
2311 environment variable
2313 and which can be fine-tuned by the user via the internal variable
2317 On top of what \*(UA knows about the terminal the boolean variable
2319 defines wether the actually applicable colour and font attribute
2320 sequences should also be generated when output is going to be paged
2321 through the external program defined by the environment variable
2326 This is not enabled by default because different pager programs need
2327 different command line switches or other configuration in order to
2328 support those sequences.
2329 \*(UA however knows about some widely used pagers and in a clean
2330 environment it is often enough to simply set
2332 please refer to that variable for more on this topic.
2337 is set then any active usage of colour and font attribute sequences
2338 is suppressed, but without affecting possibly established
2343 To define and control colours and font attributes a single multiplexer
2344 command family exists:
2346 shows or defines colour mappings for the given colour type (e.g.,
2349 can be used to remove mappings of a given colour type.
2350 Since colours are only available in interactive mode, it may make
2351 sense to conditionalize the colour setup by encapsulating it with
2354 .Bd -literal -offset indent
2355 if terminal && $features =@ +colour
2356 colour iso view-msginfo ft=bold,fg=green
2357 colour iso view-header ft=bold,fg=red "from,subject"
2358 colour iso view-header fg=red
2360 uncolour iso view-header from,subject
2361 colour iso view-header ft=bold,fg=magenta,bg=cyan
2362 colour 256 view-header ft=bold,fg=208,bg=230 subject,from
2363 colour mono view-header ft=bold
2364 colour mono view-header ft=bold,ft=reverse subject,from
2368 .\" }}} (DESCRIPTION)
2371 .\" .Sh COMMANDS {{{
2374 Each command is typed on a line by itself,
2375 and may take arguments following the command word.
2376 Command names may be abbreviated, in which case the first command that
2377 matches the given prefix will be used.
2380 can be used to show the list of all commands, either alphabetically
2381 sorted or in prefix search order (these don't match, also because the
2382 POSIX standard prescribes a set of abbreviations).
2383 \*(OPally the command
2387 when given an argument, will show a documentation string for the
2388 command matching the expanded argument, as in
2390 which should be a shorthand of
2394 For commands which take message lists as arguments, the next message
2395 forward that satisfies the command's requirements will be used shall no
2396 explicit message list have been specified.
2397 If there are no messages forward of the current message,
2398 the search proceeds backwards,
2399 and if there are no good messages at all,
2400 \*(UA shows an error message and aborts the command.
2401 \*(ID Non-message-list arguments can be quoted using the following methods:
2404 .Bl -bullet -compact -offset indent
2406 An argument can be enclosed between paired double-quotes
2411 any white space, shell word expansion, or backslash characters (except
2412 as described next) within the quotes are treated literally as part of
2414 A double-quote will be treated literally within single-quotes and vice
2416 Inside such a quoted string the actually used quote character can be
2417 used nonetheless by escaping it with a backslash
2423 An argument that is not enclosed in quotes, as above, can usually still
2424 contain space characters if those spaces are backslash-escaped, as in
2428 A backslash outside of the enclosing quotes is discarded
2429 and the following character is treated literally as part of the argument.
2434 Some commands which don't take message-list arguments can also be
2435 prefixed with the special keyword
2437 to choose \*(INible behaviour, and some new commands support only the
2438 new quoting style (without that keyword) and are flagged \*(NQ.
2439 In the future \*(UA will (mostly) use
2441 compatible argument parsing:
2442 Non-message-list arguments can be quoted using the following shell-style
2443 mechanisms: the escape character, single-quotes, double-quotes and
2444 dollar-single-quotes; any unquoted number sign
2446 starts a comment that ends argument processing.
2447 The overall granularity of error reporting and diagnostics, also
2448 regarding function arguments and their content, will improve.
2452 .Bl -bullet -compact -offset indent
2454 The literal value of any character can be preserved by preceeding it
2455 with the escape character backslash
2459 will cause variable expansion of the given name: \*(UA
2460 .Sx "INTERNAL VARIABLES"
2463 (shell) variables can be accessed through this mechanism, brace
2464 enclosing the name is supported.
2467 Arguments which are enclosed in
2468 .Ql 'single-\:quotes'
2469 retain their literal value.
2470 A single-quote cannot occur within single-quotes.
2473 The literal value of all characters enclosed in
2474 .Ql \(dqdouble-\:quotes\(dq
2475 is retained, with the exception of dollar
2477 which will cause variable expansion, as above, backquote (grave accent)
2479 (which not yet means anything special), backslash
2481 which will escape any of the characters dollar
2483 (to prevent variable expansion), backquote (grave accent)
2487 (to prevent ending the quote) and backslash
2489 (to prevent escaping, i.e., to embed a backslash character as-is), but
2490 has no special meaning otherwise.
2493 Arguments enclosed in
2494 .Ql $'dollar-\:single-\:quotes'
2495 extend normal single quotes in that backslash escape sequences are
2496 expanded as follows:
2498 .Bl -tag -compact -width "Ql \eNNN"
2504 an escape character.
2506 an escape character.
2518 backslash character.
2522 double quote (escaping is optional).
2524 eight-bit byte with the octal value
2526 (one to three octal digits), optionally with an additional
2529 A 0 byte will suppress further output for the quoted argument.
2531 eight-bit byte with the hexadecimal value
2533 (one or two hexadecimal characters).
2534 A 0 byte will suppress further output for the quoted argument.
2536 the Unicode / ISO-10646 character with the hexadecimal codepoint value
2538 (one to eight hexadecimal digits) \(em note that Unicode defines the
2539 maximum code to be ever supported as
2544 This escape is only supported in locales which support Unicode (see
2545 .Sx "Character sets" ) ,
2546 in other cases the sequence will remain unexpanded unless the given code
2547 point is ASCII compatible.
2548 The character NUL will suppress further output for the quoted argument.
2552 except it takes only one to four hexadecimal digits.
2557 This is a mechanism that allows usage of the non-printable (ASCII and
2558 compatible) control codes 0 to 31: to be able to create a printable
2559 representation the numeric value 64 is added to the control code of
2560 desire, and the resulting ASCII character set code point is then
2561 printed, e.g., BEL is
2562 .Ql 7 + 64 = 71 = G .
2563 Often circumflex notation is used for the visualization purpose, e.g,
2565 but the reverse solid notation has been standardized:
2567 The control code NUL
2569 ends argument processing without producing further output.
2571 Non-standard extension: expand the given variable name, as above.
2572 Brace enclosing the name is supported.
2574 Not yet supported, just to raise awareness: Non-standard extension.
2580 .Sy Compatibility notes:
2581 \*(ID Note these are new mechanisms which are not supported by all
2583 Round-tripping (feeding in things shown in list modes again) are not yet
2584 stable or possible at all.
2585 Before \*(UA will switch entirely to shell-style argument parsing there
2586 will be a transition phase where using
2588 will emit obsoletion warnings.
2589 E.g., the following are equivalent:
2591 .Bd -literal -offset indent
2592 mlist @any\e\e.where\e\e.example\e\e.com
2593 wysh mlist '@any\e.where\e.example\e.com' # This is a comment
2594 wysh mlist $'@any\e\e\ex2Ewhere\e\e.example\e\e\e56com' # A comment
2595 wysh mlist "@any\e.where\e.example\e.com"
2599 In any event an unquoted backslash at the end of a command line is
2600 discarded and the next line continues the command.
2601 \*(ID Note that line continuation is handled before the above parsing is
2602 applied, i.e., the parsers documented above will see merged lines.
2603 Filenames, where expected, are subsequently subjected to the following
2604 transformations, in sequence:
2607 .Bl -bullet -compact -offset indent
2609 If the filename begins with an unquoted plus sign, and the
2611 variable is defined,
2612 the plus sign will be replaced by the value of the
2614 variable followed by a slash.
2617 variable is unset or is set to null, the filename will be unchanged.
2620 Meta expansions are applied to the filename: a leading tilde
2622 character will be replaced by the expansion of
2624 except when followed by a valid user name, in which case the home
2625 directory of the given user is used instead.
2630 will be replaced by the expansion of the variable, if possible; \*(UA
2631 .Sx "INTERNAL VARIABLES"
2634 (shell) variables can be accessed through this mechanism, and the usual
2635 escape mechanism has to be applied to prevent interpretation.
2636 If the fully expanded filename results in multiple pathnames and the
2637 command is expecting only one file, an error results.
2639 In interactive context, in order to allow simple value acceptance (via
2641 arguments will usually be displayed in a properly quoted form, e.g., a file
2642 .Ql diet\e is \ecurd.txt
2644 .Ql 'diet\e is \ecurd.txt' .
2648 The following commands are available:
2650 .Bl -tag -width ".Ic _ccount"
2657 ) command which follows.
2661 The comment-command causes the entire line to be ignored.
2663 this really is a normal command which' purpose is to discard its
2666 indicating special character, which means that, e.g., trailing comments
2667 on a line are not possible.
2671 Goes to the next message in sequence and types it
2677 Display the preceding message, or the n'th previous message if given
2678 a numeric argument n.
2682 Show the current message number (the
2687 Show a brief summary of commands.
2688 \*(OP Given an argument a synopsis for the command in question is
2689 shown instead; commands can be abbreviated in general and this command
2690 can be used to see the full expansion of an abbreviation including the
2691 synopsis, try, e.g.,
2696 and see how the output changes.
2706 Interprets the remainder of the word as a macro name and passes it
2711 is a shorter synonym for
2712 .Ql call Ar mymacro .
2716 (ac) Creates, selects or lists (an) account(s).
2717 Accounts are special incarnations of
2719 macros and group commands and variable settings which together usually
2720 arrange the environment for the purpose of creating an email account.
2721 Different to normal macros settings which are covered by
2723 \(en here by default enabled! \(en will not be reverted before the
2728 (case-insensitive) always exists, and all but it can be deleted via
2731 Without arguments a listing of all defined accounts is shown.
2732 With one argument the given account is activated: the system
2734 box of that account will be activated (as via
2736 and a possibly installed
2739 The two argument form is identical to defining a macro as via
2741 .Bd -literal -offset indent
2743 set folder=~/mail MAIL=+syste.mbox record=+sent.mbox
2744 set from='myname@myisp.example (My Name)'
2745 set smtp=smtp://mylogin@smtp.myisp.example
2751 (a) With no arguments, shows all currently-defined aliases.
2752 With one argument, shows that alias.
2753 With more than one argument,
2754 creates a new alias or appends to an existing one.
2756 can be used to delete aliases.
2760 (alt) Manage a list of alternate addresses / names of the active user,
2761 members of which will be removed from recipient lists when replying to
2764 variable is not set).
2765 If arguments are given the set of alternate names is replaced by them,
2766 without arguments the current set is displayed.
2770 Takes a message list and marks each message as having been answered.
2771 This mark has no technical meaning in the mail system;
2772 it just causes messages to be marked in the header summary,
2773 and makes them specially addressable.
2777 Calls a macro that has been created via
2782 (ch) Change the working directory to
2784 or the given argument.
2790 \*(OP Only applicable to S/MIME signed messages.
2791 Takes a message list and a file name and saves the certificates
2792 contained within the message signatures to the named file in both
2793 human-readable and PEM format.
2794 The certificates can later be used to send encrypted messages to the
2795 respective message senders by setting
2796 .Va smime-encrypt-USER@HOST
2801 (ch) Change the working directory to
2803 or the given argument.
2809 Only applicable to threaded mode.
2810 Takes a message list and makes all replies to these messages invisible
2811 in header summaries, unless they are in state
2817 \*(OP\*(NQ Manage colour mappings for the type of colour given as the
2818 (case-insensitive) first argument, which must be one of
2820 for 256-colour terminals,
2825 for the standard 8-colour ANSI / ISO 6429 color palette and
2829 for monochrome terminals.
2830 Monochrome terminals cannot deal with colours, but only (some) font
2834 Without further arguments the list of all currently defined mappings
2835 for the given colour type is shown (as a special case giving
2839 will iterate over all types in order).
2840 Otherwise the second argument defines the mappable slot, the third
2841 argument a (comma-separated list of) colour and font attribute
2842 specification(s), and the optional fourth argument can be used to
2843 specify a precondition: if conditioned mappings exist they are tested in
2844 (creation) order unless a (case-insensitive) match has been found, and
2845 the default mapping (if any has been established) will only be chosen as
2847 The types of precondition available depend on the mappable slot, the
2848 following of which exist:
2851 Mappings prefixed with
2853 are used for the \*(OPal builtin Mailx-Line-Editor (MLE, see
2854 .Sx "On terminal control and line editor" )
2855 and don't support preconditions.
2857 .Bl -tag -compact -width view-partinfo
2859 This mapping is used for the position indicator that is visible when
2860 a line cannot be fully displayed on the screen.
2867 Mappings prefixed with
2869 are used in header summaries, and they all understand the preconditions
2871 (the current message) and
2873 for elder messages (only honoured in conjunction with
2874 .Va datefield-markout-older ) .
2876 .Bl -tag -compact -width view-partinfo
2878 This mapping is used for the
2880 that can be created with the
2884 formats of the variable
2887 For the complete header summary line except the
2889 and the thread structure.
2891 For the thread structure which can be created with the
2893 format of the variable
2898 Mappings prefixed with
2900 are used when displaying messages.
2902 .Bl -tag -compact -width view-partinfo
2904 This mapping is used for so-called
2906 lines, which are MBOX file format specific header lines.
2909 A comma-separated list of headers to which the mapping applies may be
2910 given as a precondition; if the \*(OPal regular expression support is
2911 available then if any of the
2913 (extended) regular expression characters is seen the precondition will
2914 be evaluated as (an extended) one.
2916 For the introductional message info line.
2917 .It Cd view-partinfo
2918 For MIME part info lines.
2922 The following (case-insensitive) colour definitions and font attributes
2923 are understood, multiple of which can be specified in a comma-separated
2933 It is possible (and often applicable) to specify multiple font
2934 attributes for a single mapping.
2937 foreground colour attribute:
2947 To specify a 256-color mode a decimal number colour specification in
2948 the range 0 to 255, inclusive, is supported, and interpreted as follows:
2950 .Bl -tag -compact -width "999 - 999"
2952 the standard ISO 6429 colors, as above.
2954 high intensity variants of the standard colors.
2956 216 colors in tuples of 6.
2958 grayscale from black to white in 24 steps.
2960 .Bd -literal -offset indent
2962 fg() { printf "\e033[38;5;${1}m($1)"; }
2963 bg() { printf "\e033[48;5;${1}m($1)"; }
2965 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
2966 printf "\e033[0m\en"
2968 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
2969 printf "\e033[0m\en"
2973 background colour attribute (see
2975 for possible values).
2979 Mappings may be removed with the command
2981 For a generic overview see the section
2982 .Sx "Coloured display" .
2987 (C) Copy messages to files whose names are derived from the author of
2988 the respective message and don't mark them as being saved;
2989 otherwise identical to
2994 (c) Copy messages to the named file and don't mark them as being saved;
2995 otherwise identical to
3000 \*(NQ With no arguments, shows all currently-defined custom headers.
3001 With one argument, shows that custom header.
3002 With more than one argument, creates a new or replaces an existing
3003 custom header with the name given as the first argument, the content of
3004 which being defined by the concatenated remaining arguments.
3006 can be used to delete custom headers.
3007 \*(ID Overwriting of automatically managed headers is neither supported
3009 Defined custom headers will be injected into newly composed or forwarded
3012 .Dl customhdr OpenPGP id=12345678; url=http://www.YYY.ZZ
3016 may also be used to inject custom headers; it is covered by
3021 Show the name of the current working directory.
3025 \*(OP For unencrypted messages this command is identical to
3027 Encrypted messages are first decrypted, if possible, and then copied.
3031 \*(OP For unencrypted messages this command is identical to
3033 Encrypted messages are first decrypted, if possible, and then copied.
3037 Without arguments the current list of macros, including their content,
3038 is shown, otherwise a macro is defined.
3039 A macro definition is a sequence of commands in the following form:
3040 .Bd -literal -offset indent
3049 A defined macro can be invoked explicitly by using the
3053 commands, or implicitly if a macro hook is triggered, e.g., a
3055 Note that interpretation of
3057 depends on how (i.e.,
3059 normal macro, folder hook, hook, account switch) the macro is invoked.
3060 Macros can be deleted via
3064 Macro behaviour, including option localization, will change in v15.
3065 Please be aware of that and possibly embed a version check in a resource
3070 (d) Marks the given message list as
3072 Deleted messages will neither be saved in
3074 nor will they be available for most other commands.
3086 Deletes the current message and displays the next message.
3087 If there is no next message, \*(UA says
3094 up or down by one message when given
3098 argument, respectively.
3102 Takes a message list and marks each given message as a draft.
3103 This mark has no technical meaning in the mail system;
3104 it just causes messages to be marked in the header summary,
3105 and makes them specially addressable.
3109 (ec) Echoes its arguments after applying
3111 expansions and filename transformations, as documented for
3116 (e) Point the text editor (as defined in
3118 at each message from the given list in turn.
3119 Modified contents are discarded unless the
3126 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3127 conditional \(em if the condition of a preceeding
3129 was false, check the following condition and execute the following block
3130 if it evaluates true.
3135 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3136 conditional \(em if none of the conditions of the preceeding
3140 commands was true, the
3146 (en) Marks the end of an
3147 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3148 conditional execution block.
3153 \*(NQ \*(UA has a strict notion about which variables are
3154 .Sx "INTERNAL VARIABLES"
3155 and which are managed in the program
3157 Since some of the latter are a vivid part of \*(UAs functioning,
3158 however, they are transparently integrated into the normal handling of
3159 internal variables via
3163 To integrate other environment variables of choice into this
3164 transparent handling, and also to export internal variables into the
3165 process environment where they normally are not, a
3167 needs to become established with this command, as in, e.g.,
3170 .Dl environ link PERL5LIB from TZ
3173 Afterwards changing such variables with
3175 will cause automatic updates of the program environment, and therefore
3176 be inherited by newly created child processes.
3177 Sufficient system support provided (it was in BSD as early as 1987, and
3178 is standardized since Y2K) removing such variables with
3180 will remove them also from the program environment, but in any way
3181 the knowledge they ever have been
3184 Note this implies that
3186 may cause loss of links.
3191 will remove an existing link, but leaves the variables as such intact.
3192 Additionally the subcommands
3196 are provided, which work exactly the same as the documented commands
3200 but (additionally) link the variable(s) with the program environment and
3201 thus immediately export them to, or remove them from (if possible),
3202 respectively, the program environment.
3207 \*(OP Since \*(UA uses the console as a user interface it can happen
3208 that messages scroll by too fast to become recognized.
3209 Optionally an error message ring queue is available which stores
3210 duplicates of any error message and notifies the user in interactive
3211 sessions whenever a new error has occurred.
3212 The queue is finite: if its maximum size is reached any new message
3213 replaces the eldest.
3216 can be used to manage this message queue: if given
3218 or no argument the queue will be displayed and cleared,
3220 will only clear all messages from the queue.
3224 (ex or x) Exit from \*(UA without changing the active mailbox and skip
3225 any saving of messages in
3227 as well as a possibly tracked line editor history file.
3231 Show the list of features that have been compiled into \*(UA.
3232 (Outputs the contents of the variable
3239 but open the mailbox readonly.
3243 (fi) The file command switches to a new mailbox.
3244 Without arguments it shows status information of the current mailbox.
3245 If an argument is given, it will write out changes (such as deletions)
3246 the user has made and open a new mailbox.
3247 Some special conventions are recognized for the
3251 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
3253 (number sign) means the previous file,
3255 (percent sign) means the invoking user's system
3259 means the primary system mailbox of
3261 (and never the value of
3263 regardless of its actual setting),
3265 (ampersand) means the invoking user's
3275 expands to the same value as
3277 but the file is handled as a primary system mailbox by, e.g., the
3281 commands, meaning that messages that have been read in the current
3282 session will be moved to the
3284 mailbox instead of simply being flagged as read.
3287 If the name matches one of the strings defined with the command
3289 it is replaced by its long form and expanded.
3290 If the name ends with
3295 it is treated as being compressed with
3300 respectively, and transparently handled through an intermediate
3301 (un)compression step (using a temporary file) with the according
3302 facility, sufficient support provided.
3303 Likewise, if the named file doesn't exist, but a file with one of the
3304 mentioned compression extensions does, then the name is automatically
3305 expanded and the compressed file is used.
3307 Otherwise, if the name ends with an extension for which
3308 .Va file-hook-load-EXTENSION
3310 .Va file-hook-save-EXTENSION
3311 variables are set, then the given hooks will be used to load and save
3313 and \*(UA will work with an intermediate temporary file.
3315 MBOX files (flat file-based mailboxes) are generally locked during file
3316 operations in order to avoid inconsistencies due to concurrent
3318 \*(OPal Mailbox files which \*(UA treats as system
3320 boxes or primary mailboxes will also be protected by so-called dotlock
3321 files, the traditional way of mail spool file locking: for any file
3325 will be created for the duration of the synchronization \(em
3326 as necessary a privilege-separated dotlock child process will be used
3327 to accommodate for necessary privilege adjustments in order to create
3328 the dotlock file in the same directory
3329 and with the same user and group identities as the file of interest.
3332 for fine-tuning the handling of MBOX files.
3336 refers to a directory with the subdirectories
3341 then it is treated as a folder in
3343 format; \*(ID the variable
3345 can be used to control the format of yet non-existent folders.
3348 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3349 .Dl \*(OU protocol://[user@]host[:port][/path]
3351 is taken as an Internet mailbox specification.
3352 The \*(OPally supported protocols are
3356 (POP3 with SSL/TLS encrypted transport).
3359 part is valid only for IMAP; there it defaults to
3361 Also see the section
3362 .Sx "On URL syntax and credential lookup" .
3366 contains special characters, in particular
3370 they must be escaped in URL notation \(en the command
3372 can be used to show the necessary conversion.
3376 Takes a message list and marks the messages as
3378 ged for urgent/special attention.
3379 This mark has no technical meaning in the mail system;
3380 it just causes messages to be highlighted in the header summary,
3381 and makes them specially addressable.
3390 With no arguments, list the names of the folders in the folder directory.
3391 With an existing folder as an argument,
3392 lists the names of folders below the named folder.
3398 but saves the message in a file named after the local part of the first
3399 recipient's address (instead of in
3406 but saves the message in a file named after the local part of the first
3407 recipient's address (instead of in
3414 but responds to all recipients regardless of the
3419 .It Ic followupsender
3422 but responds to the sender only regardless of the
3438 (f) Takes a list of message specifications and displays a summary of
3439 their message headers, as via
3441 An alias of this command is
3444 .Sx "Specifying messages" .
3450 but saves the message in a file named after the local part of the
3451 recipient's address (instead of in
3456 Takes a message and the address of a recipient
3457 and forwards the message to him.
3458 The text of the original message is included in the new one,
3459 with the value of the
3461 variable preceding it.
3466 commands specify which header fields are included in the new message.
3467 Only the first part of a multipart message is included unless the
3468 .Va forward-as-attachment
3472 is set recipient addresses will be stripped from comments, names etc.
3476 Specifies which header fields are to be ignored with the command
3478 This command has no effect when the
3479 .Va forward-as-attachment
3484 Specifies which header fields are to be retained with the command
3489 This command has no effect when the
3490 .Va forward-as-attachment
3495 Define or list command aliases, so-called ghosts.
3496 Without arguments a list of all currently known aliases is shown.
3497 With one argument the expansion of the given alias is shown.
3498 With two or more arguments a command alias is defined or updated: the
3499 first argument is the name under which the remaining command line should
3500 be accessible, the content of which can be just about anything.
3501 A ghost can be used everywhere a normal command can be used, but always
3502 takes precedence; any arguments that are given to the command alias are
3503 joined onto the alias content, and the resulting string forms the
3504 command line that is, in effect, executed.
3507 .Bd -literal -offset indent
3509 `ghost': no such alias: "xx"
3512 ghost xx "echo hello,"
3521 (h) Show the current group of headers, the size of which depends on
3524 and the style of which can be adjusted with the variable
3526 If a message-specification is given the group of headers containing the
3527 first message therein is shown and the message at the top of the screen
3542 the list of history entries;
3545 argument selects and shows the respective history entry \(en
3548 to accept it, and the history entry will become the new history top.
3549 The default mode if no arguments are given is
3556 Takes a message list and marks each message therein to be saved in the
3561 Does not override the
3564 \*(UA deviates from the POSIX standard with this command, because a
3566 command issued after
3568 will display the following message, not the current one.
3573 (i) Part of the nestable
3574 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3575 conditional execution construct \(em if the given condition is true then
3576 the encapsulated block is executed.
3577 POSIX only supports the (case-insensitive) conditions
3582 end, all remaining conditions are non-portable extensions; note that
3583 falsely specified conditions cause the execution of the entire
3584 conditional construct until the (matching) closing
3586 command to be suppressed.
3587 The syntax of the nestable
3589 conditional execution construct requires that each condition and syntax
3590 element is surrounded by whitespace.
3592 .Bd -literal -offset indent
3601 The (case-insensitive) condition
3603 erminal will evaluate to true if the standard input is a terminal, i.e.,
3604 in interactive sessions.
3605 Another condition can be any boolean value (see the section
3606 .Sx "INTERNAL VARIABLES"
3607 for textual boolean representations) to mark an enwrapped block as
3610 .Dq always execute .
3611 It is possible to check
3612 .Sx "INTERNAL VARIABLES"
3615 variables for existence or compare their expansion against a user given
3616 value or another variable by using the
3618 .Pf ( Dq variable next )
3619 conditional trigger character;
3620 a variable on the right hand side may be signalled using the same
3622 The variable names may be enclosed in a pair of matching braces.
3625 The available comparison operators are
3629 (less than or equal to),
3635 (greater than or equal to),
3639 (is substring of) and
3641 (is not substring of).
3642 The values of the left and right hand side are treated as strings and
3643 are compared 8-bit byte-wise, ignoring case according to the rules of
3644 the US-ASCII encoding (therefore, dependend on the active locale,
3645 possibly producing false results for strings in the locale encoding).
3646 Except for the substring checks the comparison will instead be performed
3647 arithmetically if both, the user given value as well as the variable
3648 content, can be parsed as numbers (integers).
3649 An unset variable is treated as the empty string.
3652 When the \*(OPal regular expression support is available, the additional
3658 They treat the right hand side as an extended regular expression that is
3659 matched case-insensitively and according to the active
3661 locale, meaning that strings in the locale encoding should be matched
3665 Conditions can be joined via AND-OR lists (where the AND operator is
3667 and the OR operator is
3669 which have equal precedence and will be evaluated with left
3670 associativity, thus using the same syntax that is known for the
3672 It is also possible to form groups of conditions and lists by enclosing
3673 them in pairs of brackets
3674 .Ql [\ \&.\&.\&.\ ] ,
3675 which may be interlocked within each other, and also be joined via
3679 The results of individual conditions and entire groups may be modified
3680 via unary operators: the unary operator
3682 will reverse the result.
3684 .Bd -literal -offset indent
3688 if $ttycharset == "UTF-8"
3689 echo *ttycharset* is set to UTF-8, case-insensitively
3693 echo These two variables are equal
3695 if $version-major >= 15
3696 echo Running a new version..
3697 if $features =@ "regex"
3698 if $TERM =~ "^xterm\&.*"
3699 echo ..in an X terminal
3702 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
3705 if true && $debug || ${verbose}
3706 echo Left associativity, as is known from the shell
3708 if ! ! true && ! [ ! $debug && ! $verbose ]
3709 echo Unary operator support
3717 Without arguments the list of ignored header fields is shown,
3718 otherwise the given list of header fields is added to the ignore list:
3719 Header fields in the ignore list are not shown on the terminal when
3720 a message is displayed.
3721 To display a message in its entirety, use the commands
3732 Shows the names of all available commands, alphabetically sorted.
3733 If given any non-whitespace argument the list will be shown in the order
3734 in which command prefixes are searched.
3738 This command can be used to localize changes to variables, meaning that
3739 their state will be reverted to the former one once the covered scope
3741 It can only be used inside of macro definition blocks introduced by
3745 and is interpreted as a boolean (string, see
3746 .Sx "INTERNAL VARIABLES" ) ;
3749 of an account is left once it is switched off again.
3750 .Bd -literal -offset indent
3751 define temporary_settings {
3766 enables change localization and calls
3768 which explicitly resets localization, then any value changes within
3770 will still be reverted by
3772 \*(ID Once the outermost level, the one which enabled localization
3773 first, is left, but no earlier, all adjustments will be unrolled.
3777 Reply to messages that come in via known
3780 .Pf ( Ic mlsubscribe )
3781 mailing lists, or pretend to do so (see
3782 .Sx "Mailing lists" ) :
3785 functionality this will actively resort and even remove message
3786 recipients in order to generate a message that is supposed to be sent to
3788 For example it will also implicitly generate a
3789 .Ql Mail-Followup-To:
3790 header if that seems useful, regardless of the setting of the variable
3797 but saves the message in a file named after the local part of the first
3798 recipient's address (instead of in
3803 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3804 or asks on standard input if none were given;
3805 then collects the remaining mail content and sends it out.
3809 (mb) The given message list is to be sent to
3811 when \*(UA is quit; this is the default action unless the
3814 \*(ID This command can only be used in a primary system mailbox (see
3819 Without any arguments the content of the MIME type cache will displayed.
3820 Otherwise each argument defines a complete MIME type specification of
3821 a type that shall be added (prepended) to the cache.
3822 In any event MIME type sources are loaded first as necessary \(en
3823 .Va mimetypes-load-control
3824 can be used to fine-tune which sources are actually loaded.
3825 Refer to the section on
3826 .Sx "The mime.types files"
3827 for more on MIME type specifications and this topic in general.
3828 MIME type unregistration and cache resets can be triggered with
3833 Without arguments the list of all currently defined mailing lists
3834 (and their attributes, if any) is shown; a more verbose listing will be
3835 produced if either of
3840 Otherwise all given arguments (which need not be quoted except for
3841 whitespace) will be added and henceforth be recognized as mailing lists.
3842 Mailing lists may be removed via the command
3845 If the \*(OPal regular expression support is available then mailing
3846 lists may also be specified as (extended) regular expressions (see
3852 Without arguments the list of all currently defined mailing lists which
3853 have a subscription attribute is shown; a more verbose listing will be
3854 produced if either of
3859 Otherwise this attribute will be set for all given mailing lists,
3860 newly creating them as necessary (as via
3862 Subscription attributes may be removed via the command
3871 but moves the messages to a file named after the local part of the
3872 sender address of the first message (instead of in
3879 but marks the messages for deletion if they were transferred
3886 but also displays ignored header fields and all MIME parts.
3894 on the given messages, even in non-interactive mode and as long as the
3895 standard output is a terminal.
3901 \*(OP When used without arguments or if
3903 has been given the content of the
3905 cache is shown, loading it first as necessary,
3908 then the cache will only be initialized and
3910 will remove its contents.
3911 Note that \*(UA will try to load the file only once, use
3912 .Ql Ic \&\&netrc Ns \:\0\:clear
3913 to unlock further attempts.
3917 .Sx "On URL syntax and credential lookup" ;
3919 .Sx "The .netrc file"
3920 documents the file format in detail.
3924 Checks for new mail in the current folder without committing any changes
3926 If new mail is present, a message is shown.
3930 the headers of each new message are also shown.
3938 Goes to the next message in sequence and types it.
3939 With an argument list, types the next matching message.
3953 If the current folder is accessed via a network connection, a
3955 command is sent, otherwise no operation is performed.
3961 but also displays ignored header fields and all MIME parts.
3969 on the given messages, even in non-interactive mode and as long as the
3970 standard output is a terminal.
3978 but also pipes ignored header fields and all parts of MIME
3979 .Ql multipart/alternative
3984 (pi) Takes a message list and a shell command
3985 and pipes the messages through the command.
3986 Without an argument the current message is piped through the command
3993 every message is followed by a formfeed character.
4014 (q) Terminates the session, saving all undeleted, unsaved messages in
4017 preserving all messages marked with
4021 or never referenced in the system
4023 box, and removing all other messages from the primary system mailbox.
4024 If new mail has arrived during the session,
4026 .Dq You have new mail
4028 If given while editing a mailbox file with the command line flag
4030 then the edit file is rewritten.
4031 A return to the shell is effected,
4032 unless the rewrite of edit file fails,
4033 in which case the user can escape with the exit command.
4047 Removes the named files or directories.
4048 If a name refer to a mailbox, e.g., a Maildir mailbox, then a mailbox
4049 type specific removal will be performed, deleting the complete mailbox.
4050 The user is asked for confirmation in interactive mode.
4054 Takes the name of an existing folder
4055 and the name for the new folder
4056 and renames the first to the second one.
4057 Both folders must be of the same type.
4061 (R) Reply to originator.
4062 Does not reply to other recipients of the original message.
4064 will exchange this command with
4068 is set the recipient address will be stripped from comments, names etc.
4072 (r) Take a message and group-responds to it by addressing the sender
4075 .Va followup-to-honour ,
4078 .Va recipients-in-cc
4079 influence response behaviour.
4082 offers special support for replying to mailing lists.
4085 is set recipient addresses will be stripped from comments, names etc.
4098 but initiates a group-reply regardless of the value of
4105 but responds to the sender only regardless of the value of
4112 but does not add any header lines.
4113 This is not a way to hide the sender's identity,
4114 but useful for sending a message again to the same recipients.
4118 Takes a list of messages and a user name
4119 and sends each message to the named user.
4121 and related header fields are prepended to the new copy of the message.
4139 .It Ic respondsender
4145 (ret) Without arguments the list of retained header fields is shown,
4146 otherwise the given list of header fields is added to the retain list:
4147 Header fields in the retain list are shown on the terminal when
4148 a message is displayed, all other header fields are suppressed.
4149 To display a message in its entirety, use the commands
4158 takes precedence over the mentioned.
4164 but saves the messages in a file named after the local part of the
4165 sender of the first message instead of (in
4167 and) taking a filename argument.
4171 (s) Takes a message list and a filename and appends each message in turn
4172 to the end of the file.
4173 If no filename is given, the
4176 The filename in quotes, followed by the generated character count
4177 is echoed on the user's terminal.
4178 If editing a primary system mailbox the messages are marked for deletion.
4179 Filename interpretation as described for the
4181 command is performed.
4198 Header fields thus marked are filtered out when saving a message by
4200 or when automatically saving to
4202 This command should only be applied to header fields that do not contain
4203 information needed to decode the message,
4204 as MIME content fields do.
4216 Header fields thus marked are the only ones saved with a message when
4219 or when automatically saving to
4224 The use of this command is strongly discouraged since it may strip
4225 header fields that are needed to decode the message correctly.
4229 Takes a message specification (list) and displays a header summary of
4230 all matching messages, as via
4232 This command is an alias of
4235 .Sx "Specifying messages" .
4239 Takes a message list and marks all messages as having been read.
4243 (se) Without arguments this command shows all internal variables which
4244 are currently known to \*(UA (they have been set).
4245 A more verbose listing will be produced if either of
4249 are set, in which case variables may be preceeded with a comment line
4250 that gives some context of what \*(UA knows about the given variable.
4252 Otherwise the given variables (and arguments) are set or adjusted.
4253 Arguments are of the form
4255 (no space before or after
4259 if there is no value, i.e., a boolean variable.
4260 Quotation marks may be placed around any part of the assignment
4261 statement to quote blanks or tabs, e.g.,
4263 .Dl set indentprefix='->'
4265 If an argument begins with
4269 the effect is the same as invoking the
4271 command with the remaining part of the variable
4272 .Pf ( Ql unset save ) .
4276 that is known to map to an environment variable will automatically cause
4277 updates in the program environment (unsetting a variable in the
4278 environment requires corresponding system support).
4279 Please use the command
4281 for further environmental control.
4286 .Sx "INTERNAL VARIABLES"
4292 (sh) Invokes an interactive version of the shell.
4296 Without arguments the list of all currently defined shortcuts is
4298 Otherwise all given arguments (which need not be quoted except for
4299 whitespace) are treated as pairs of shortcuts and their expansions,
4300 creating new or changing already existing shortcuts, as necessary.
4301 Shortcuts may be removed via the command
4303 The expansion strings should be in the syntax that has been described
4312 but performs neither MIME decoding nor decryption, so that the raw
4313 message text is shown.
4317 (si) Shows the size in characters of each message of the given
4322 Shows the current sorting criterion when used without an argument.
4323 Otherwise creates a sorted representation of the current folder,
4326 command and the addressing modes such that they refer to messages in
4328 Message numbers are the same as in regular mode.
4332 a header summary in the new order is also displayed.
4333 Automatic folder sorting can be enabled by setting the
4335 variable, as in, e.g.,
4336 .Ql set autosort=thread .
4337 Possible sorting criterions are:
4339 .Bl -tag -compact -offset indent -width "subject"
4341 Sort the messages by their
4343 field, that is by the time they were sent.
4345 Sort messages by the value of their
4347 field, that is by the address of the sender.
4350 variable is set, the sender's real name (if any) is used.
4352 Sort the messages by their size.
4354 \*(OP Sort the message by their spam score, as has been classified by
4357 Sort the messages by their message status.
4359 Sort the messages by their subject.
4361 Create a threaded display.
4363 Sort messages by the value of their
4365 field, that is by the address of the recipient.
4368 variable is set, the recipient's real name (if any) is used.
4373 (so) The source command reads commands from the given file, which is
4374 subject to the usual filename expansions (see introductional words of
4376 If the given argument ends with a vertical bar
4378 then the argument will instead be interpreted as a shell command and
4379 \*(UA will read the output generated by it.
4382 cannot be used from within macros that execute as
4383 .Va folder-hook Ns s
4386 i.e., it can only be called from macros that were
4393 (beside not supporting pipe syntax a.k.a. shell command input) is that
4394 this command will not generate an error if the given file argument
4395 cannot be opened successfully.
4396 This can matter in, e.g., resource files, since loading of those is
4397 stopped when an error is encountered.
4401 \*(OP Takes a list of messages and clears their
4407 \*(OP Takes a list of messages and causes the
4409 to forget it has ever used them to train its Bayesian filter.
4410 Unless otherwise noted the
4412 flag of the message is inspected to chose wether a message shall be
4420 \*(OP Takes a list of messages and informs the Bayesian filter of the
4424 This also clears the
4426 flag of the messages in question.
4430 \*(OP Takes a list of messages and rates them using the configured
4431 .Va spam-interface ,
4432 without modifying the messages, but setting their
4434 flag as appropriate; because the spam rating headers are lost the rate
4435 will be forgotten once the mailbox is left.
4436 Refer to the manual section
4438 for the complete picture of spam handling in \*(UA.
4442 \*(OP Takes a list of messages and sets their
4448 \*(OP Takes a list of messages and informs the Bayesian filter of the
4454 flag of the messages in question.
4463 Create a threaded representation of the current folder,
4464 i.\|e. indent messages that are replies to other messages in the header
4465 display and change the
4467 command and the addressing modes such that they refer to messages in the
4469 Message numbers are the same as in unthreaded mode.
4473 a header summary in threaded order is also displayed.
4477 (to) Takes a message list and displays the top few lines of each.
4478 The number of lines shown is controlled by the variable
4483 (tou) Takes a message list and marks the messages for saving in
4485 \*(UA deviates from the POSIX standard with this command,
4488 command will display the following message instead of the current one.
4494 but also displays out ignored header fields and all parts of MIME
4495 .Ql multipart/alternative
4500 (t) Takes a message list and types out each message on the user's
4506 For MIME multipart messages, all parts with a content type of
4510 are shown, the other are hidden except for their headers.
4511 Messages are decrypted and converted to the terminal character set
4516 Delete all given accounts.
4517 An error message is shown if a given account is not defined.
4520 will discard all existing accounts.
4524 (una) Takes a list of names defined by alias commands
4525 and discards the remembered groups of users.
4528 will discard all existing aliases.
4532 Takes a message list and marks each message as not having been answered.
4536 Only applicable to threaded mode.
4537 Takes a message list and makes the message and all replies to it visible
4538 in header summaries again.
4539 When a message becomes the current message,
4540 it is automatically made visible.
4541 Also when a message with collapsed replies is displayed,
4542 all of these are automatically uncollapsed.
4548 mapping for the given colour type (see
4550 for a list of types) and mapping; if the optional precondition argument
4551 is used then only the exact tuple of mapping and precondition is removed.
4554 will remove all mappings (no precondition allowed).
4556 .Sx "Coloured display"
4557 for the general picture.
4561 Deletes the custom headers given as arguments.
4564 will remove all custom headers.
4568 Undefine all given macros.
4569 An error message is shown if a given macro is not defined.
4572 will discard all existing macros.
4576 (u) Takes a message list and marks each message as not being deleted.
4580 Takes a message list and
4586 Takes a message list and marks each message as not being
4591 Removes the header field names from the list of ignored fields for the
4596 will remove all fields.
4600 Removes the header field names from the list of retained fields for the
4605 will remove all fields.
4609 Remove all the given command
4613 will remove all ghosts.
4617 Removes the header field names from the list of ignored fields.
4620 will remove all fields.
4624 Delete all given MIME types, e.g.,
4625 .Ql unmimetype text/plain
4626 will remove all registered specifications for the MIME type
4630 will discard all existing MIME types, just as will
4632 but which also reenables cache initialization via
4633 .Va mimetypes-load-control .
4637 Forget about all the given mailing lists.
4640 will remove all lists.
4645 .It Ic unmlsubscribe
4646 Remove the subscription attribute from all given mailing lists.
4649 will clear the attribute from all lists which have it set.
4660 Takes a message list and marks each message as not having been read.
4664 Removes the header field names from the list of retained fields.
4667 will remove all fields.
4671 Removes the header field names from the list of ignored fields for
4675 will remove all fields.
4679 Removes the header field names from the list of retained fields for
4683 will remove all fields.
4687 (uns) Takes a list of internal variable names and discards their
4688 remembered values; the reverse of
4695 Deletes the shortcut names given as arguments.
4698 will remove all shortcuts.
4702 Disable sorted or threaded mode
4708 return to normal message order and,
4712 displays a header summary.
4722 Decode the given URL-encoded string arguments and show the results.
4723 Note the resulting strings may not be valid in the current locale, see
4728 URL-encode the given arguments and show the results.
4729 Because the arguments effectively are in the character set of the
4730 current locale the results will vary accordingly unless the input solely
4731 consists of characters in the portable character set, see
4732 .Sx "Character sets" .
4736 Edit the values of or create the given variable(s) in the
4738 Boolean variables cannot be edited.
4742 This command produces the same output as the listing mode of
4746 ity adjustments, but only for the given variables.
4750 \*(OP Takes a message list and verifies each message.
4751 If a message is not a S/MIME signed message,
4752 verification will fail for it.
4753 The verification process checks if the message was signed using a valid
4755 if the message sender's email address matches one of those contained
4756 within the certificate,
4757 and if the message content has been altered.
4761 (v) Takes a message list and invokes the display editor on each message.
4762 Modified contents are discarded unless the
4768 (w) For conventional messages the body without all headers is written.
4769 The output is decrypted and converted to its native format as necessary.
4770 If the output file exists, the text is appended.
4771 If a message is in MIME multipart format its first part is written to
4772 the specified file as for conventional messages,
4773 and the user is asked for a filename to save each other part.
4774 For convience saving of each part may be skipped by giving an empty value;
4775 the same result can also be achieved by writing it to
4777 For the second and subsequent parts a leading
4779 character causes the part to be piped to the remainder of the user input
4780 interpreted as a shell command;
4781 otherwise the user input is expanded as usually for folders,
4782 e.g., tilde expansion is performed.
4783 In non-interactive mode, only the parts of the multipart message
4784 that have a filename given in the part header are written,
4785 the others are discarded.
4786 The original message is never marked for deletion in the originating
4789 the contents of the destination file are overwritten if the file
4791 No special handling of compressed files is performed.
4800 \*(UA presents message headers in windowfuls as described under the
4803 This command scrolls to the next window of messages.
4804 If an argument is given,
4805 it specifies the window to use.
4806 A number prefixed by
4810 indicates that the window is calculated in relation to the current position.
4811 A number without a prefix specifies an absolute window number,
4814 lets \*(UA scroll to the last window of messages.
4820 but scrolls to the next or previous window that contains at least one
4829 .\" .Sh TILDE ESCAPES {{{
4832 Here is a summary of the tilde escapes,
4833 which are used to perform special functions when composing messages.
4834 Tilde escapes are only recognized at the beginning of lines.
4837 is somewhat of a misnomer since the actual escape character can be
4838 changed by adjusting the option
4841 .Bl -tag -width ".Ic __ filename"
4844 Insert the string of text in the message prefaced by a single
4846 (If the escape character has been changed,
4847 that character must be doubled
4848 in order to send it at the beginning of a line.)
4851 .It Ic ~! Ar command
4852 Execute the indicated shell
4854 then return to the message.
4858 Same effect as typing the end-of-file character.
4861 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4862 Execute the given \*(UA command.
4863 Not all commands, however, are allowed.
4867 Write a summary of command escapes.
4870 .It Ic ~< Ar filename
4875 .It Ic ~<! Ar command
4877 is executed using the shell.
4878 Its standard output is inserted into the message.
4881 .It Ic ~@ Op Ar filename...
4882 With no arguments, edit the attachment list interactively.
4883 If an attachment's file name is left empty,
4884 that attachment is deleted from the list.
4885 When the end of the attachment list is reached,
4886 \*(UA will ask for further attachments until an empty name is given.
4887 If a given file name solely consists of the number sign
4889 followed by a valid message number of the currently active mailbox, then
4890 the given message is attached as a MIME
4892 and the rest of this section does not apply.
4894 If character set conversion has been compiled into \*(UA, then this mode
4895 gives the user the option to specify input and output character sets,
4896 unless the file extension indicates binary content, in which case \*(UA
4897 asks wether this step shall be skipped for the attachment in question.
4898 If not skipped, then the charset that succeeds to represent the
4899 attachment data will be used in the
4901 MIME parameter of the mail message:
4903 .Bl -bullet -compact
4905 If input and output character sets are specified, then the conversion is
4906 performed on the fly.
4907 The user will be asked repeatedly until the desired conversion succeeds.
4909 If only an output character set is specified, then the input is assumed
4912 charset and will be converted to the given output charset on the fly.
4913 The user will be asked repeatedly until the desired conversion succeeds.
4915 If no character sets are specified at all then the algorithm that is
4916 documented in the section
4917 .Sx "Character sets"
4918 is applied, but directly and on the fly.
4919 The user will be asked repeatedly until the desired conversion succeeds.
4921 Finally, if an input-, but no output character set is specified, then no
4922 conversion is ever performed, but the
4924 MIME parameter value will still be set to the user input.
4926 The character set selection loop can be left by typing
4928 i.e., causing an interrupt.
4929 .\" \*(OU next sentence
4930 Note that before \*(UA version 15.0 this terminates the entire
4931 current attachment selection, not only the character set selection.
4934 Without character set conversion support, \*(UA will ask for the input
4935 character set only, and it'll set the
4937 MIME parameter value to the given input, if any;
4938 if no user input is seen then the
4940 character set will be used for the parameter value instead.
4941 Note that the file extension check isn't performed in this mode, since
4942 no conversion will take place anyway.
4944 Note that in non-interactive mode, for reproduceabilities sake, there
4945 will always be two questions for each attachment, regardless of wether
4946 character set conversion is available and what the file extension is.
4947 The first asks for the filename, and the second asks for the input
4948 character set to be passed through to the corresponding MIME parameter;
4949 no conversion will be tried if there is input to the latter question,
4950 otherwise the usual conversion algorithm, as above, is applied.
4951 For message attachments, the answer to the second question is completely
4956 arguments are specified for the
4958 command they are treated as a file list of
4960 -style quoted arguments, optionally also separated by commas, which are
4961 expanded and then appended to the existing list of message attachments.
4962 Message attachments can only be added via the first method.
4963 In this mode the (text) attachments are assumed to be in
4965 encoding, and will be evaluated as documented in the section
4966 .Sx "Character sets" .
4970 Inserts the string contained in the
4973 .Ql Ic ~i Ns \0Sign ) .
4974 The escape sequences tabulator
4982 Inserts the string contained in the
4985 .Ql Ic ~i Ns \0sign ) .
4986 The escape sequences tabulator
4993 .It Ic ~b Ar name ...
4994 Add the given names to the list of blind carbon copy recipients.
4997 .It Ic ~c Ar name ...
4998 Add the given names to the list of carbon copy recipients.
5002 Read the file specified by the
5004 variable into the message.
5008 Invoke the text editor on the message collected so far.
5009 After the editing session is finished,
5010 the user may continue appending text to the message.
5013 .It Ic ~F Ar messages
5014 Read the named messages into the message being sent, including all
5015 message headers and MIME parts.
5016 If no messages are specified, read in the current message.
5019 .It Ic ~f Ar messages
5020 Read the named messages into the message being sent.
5021 If no messages are specified, read in the current message.
5025 lists are used to modify the message headers.
5026 For MIME multipart messages,
5027 only the first displayable part is included.
5031 Edit the message header fields
5036 by typing each one in turn and allowing the user to edit the field.
5037 The default values for these fields originate from the
5045 Edit the message header fields
5051 by typing each one in turn and allowing the user to edit the field.
5054 .It Ic ~i Ar variable
5055 Insert the value of the specified variable into the message,
5056 adding a newline character at the end.
5057 The message remains unaltered if the variable is unset or empty.
5058 The escape sequences tabulator
5065 .It Ic ~M Ar messages
5066 Read the named messages into the message being sent,
5069 If no messages are specified, read the current message.
5072 .It Ic ~m Ar messages
5073 Read the named messages into the message being sent,
5076 If no messages are specified, read the current message.
5080 lists are used to modify the message headers.
5081 For MIME multipart messages,
5082 only the first displayable part is included.
5086 Display the message collected so far,
5087 prefaced by the message header fields
5088 and followed by the attachment list, if any.
5092 Abort the message being sent,
5093 copying it to the file specified by the
5100 .It Ic ~R Ar filename
5101 Read the named file into the message, indented by
5105 .It Ic ~r Ar filename
5106 Read the named file into the message.
5110 Cause the named string to become the current subject field.
5113 .It Ic ~t Ar name ...
5114 Add the given name(s) to the direct recipient list.
5117 .It Ic ~U Ar messages
5118 Read in the given / current message(s) excluding all headers, indented by
5122 .It Ic ~u Ar messages
5123 Read in the given / current message(s), excluding all headers.
5127 Invoke an alternate editor (defined by the
5129 option) on the message collected so far.
5130 Usually, the alternate editor will be a screen editor.
5131 After the editor is quit,
5132 the user may resume appending text to the end of the message.
5135 .It Ic ~w Ar filename
5136 Write the message onto the named file.
5138 the message is appended to it.
5144 except that the message is not saved at all.
5147 .It Ic ~| Ar command
5148 Pipe the message through the specified filter command.
5149 If the command gives no output or terminates abnormally,
5150 retain the original text of the message.
5153 is often used as a rejustifying filter.
5158 .\" .Sh INTERNAL VARIABLES {{{
5159 .Sh "INTERNAL VARIABLES"
5161 Internal \*(UA variables are controlled via the
5165 commands; prefixing a variable name with the string
5169 has the same effect as using
5175 Creation or editing of variables can be performed in the
5180 will give more insight on the given variable(s), and
5182 when called without arguments, will show a listing of all variables.
5183 Some well-known variables will also become inherited from the
5186 implicitly, others can be explicitly imported with the command
5188 and henceforth share the said properties.
5191 Two different kind of internal variables exist.
5192 There are boolean variables, which can only be in one of the two states
5196 and value variables with a(n optional) string value.
5197 For the latter proper quoting is necessary upon assignment time, the
5198 introduction of the section
5200 documents the supported quoting rules.
5202 .Bd -literal -offset indent
5203 wysh set one=val\e 1 two="val 2" \e
5204 three='val "3"' four=$'val \e'4\e''
5205 varshow one two three four
5206 unset one two three four
5210 Dependent upon the actual option the string values will be interpreted
5211 as numbers, colour names, normal text etc., but there also exists
5212 a special kind of string value, the
5213 .Dq boolean string ,
5214 which must either be a decimal integer (in which case
5218 and any other value is true) or any of the (case-insensitive) strings
5223 for a false boolean and
5228 for a true boolean; a special kind of boolean string is the
5230 which is a boolean string that can optionally be prefixed with the
5231 (case-insensitive) term
5235 which causes prompting of the user in interactive mode, with the given
5236 boolean as the default value.
5238 .\" .Ss "Initial settings" {{{
5239 .\" (Keep in SYNC: ./nail.h:okeys, ./nail.rc, ./nail.1:"Initial settings")
5240 .Ss "Initial Settings"
5242 The standard POSIX 2008/Cor 1-2013 mandates the following initial
5248 .Pf no Va autoprint ,
5262 .Pf no Va ignoreeof ,
5264 .Pf no Va keepsave ,
5266 .Pf no Va outfolder ,
5271 (note that \*(UA deviates from the standard by using
5275 special prompt escape results in
5283 .Pf no Va sendwait ,
5292 Notes: \*(UA doesn't support the
5294 variable \(en use command line options or
5295 .Va sendmail-arguments
5296 to pass options through to a MTA.
5297 And the default global
5299 file (which is loaded unless the
5301 command line flag has been used or the
5302 .Ev NAIL_NO_SYSTEM_RC
5303 environment variable is set) bends those initial settings a bit, e.g.,
5304 it sets the variables
5309 to name a few, calls
5311 etc., and should thus be taken into account.
5314 .\" .Ss "Variables" {{{
5317 .Bl -tag -width ".It Va _utoprin_"
5319 .It Va add-file-recipients
5320 \*(BO When file or pipe recipients have been specified,
5321 mention them in the corresponding address fields of the message instead
5322 of silently stripping them from their recipient list.
5323 By default such addressees are not mentioned.
5325 .Mx Va agent-shell-lookup
5326 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5328 \*(IN\*(OP Account passwords can be fetched via an external agent
5329 program in order to permit encrypted password storage \(en see
5330 .Sx "On URL syntax and credential lookup"
5331 for more on credential lookup.
5332 If this is set then the content is interpreted as a shell command the
5333 output of which (with newline characters removed) is treated as the
5334 account password shall the command succeed (and have produced non-empty
5335 non-newline output); e.g., via
5337 .Bd -literal -offset indent
5338 $ echo PASSWORD > .pass
5340 $ eval `gpg-agent --daemon \e
5341 --pinentry-program=/usr/bin/pinentry-curses \e
5342 --max-cache-ttl 99999 --default-cache-ttl 99999`
5343 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5347 A couple of environment variables will be set for the agent:
5349 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5351 The temporary directory that \*(UA uses.
5352 Usually identical to
5354 but guaranteed to be set and usable by child processes;
5355 to ensure the latter condition for
5361 for which the password is looked up.
5362 .It Ev NAIL_USER_ENC
5363 The URL percent-encoded variant of
5366 The plain machine hostname of the user account.
5367 .It Ev NAIL_HOST_PORT
5370 (hostname possibly including port) of the user account.
5375 \*(BO Causes only the local part to be evaluated
5376 when comparing addresses.
5380 \*(BO Causes messages saved in
5382 to be appended to the end rather than prepended.
5383 This should always be set.
5387 \*(BO Causes \*(UA to prompt for the subject of each message sent.
5388 If the user responds with simply a newline,
5389 no subject field will be sent.
5393 \*(BO Causes the prompts for
5397 lists to appear after the message has been edited.
5401 \*(BO If set, \*(UA asks for files to attach at the end of each message,
5402 shall the list be found empty at that time.
5403 An empty line finalizes the list.
5407 \*(BO Causes the user to be prompted for carbon copy recipients
5408 (at the end of each message if
5412 are set) shall the list be found empty (at that time).
5413 An empty line finalizes the list.
5417 \*(BO Causes the user to be prompted for blind carbon copy
5418 recipients (at the end of each message if
5422 are set) shall the list be found empty (at that time).
5423 An empty line finalizes the list.
5427 \*(BO\*(OP Causes the user to be prompted if the message is to be
5428 signed at the end of each message.
5431 variable is ignored when this variable is set.
5435 \*(BO Alternative name for
5442 .It Va attachment-ask-content-description , \
5443 attachment-ask-content-disposition , \
5444 attachment-ask-content-id , \
5445 attachment-ask-content-type
5446 \*(BO If set then the user will be prompted for some attachment
5447 information when editing the attachment list.
5448 It is advisable to not use these but for the first of the variables;
5449 even for that it has to be noted that the data is used
5455 A sequence of characters to display in the
5459 as shown in the display of
5461 each for one type of messages (see
5462 .Sx "Message states" ) ,
5463 with the default being
5466 .Ql NU\ \ *HMFAT+\-$~
5469 variable is set, in the following order:
5471 .Bl -tag -compact -offset indent -width ".It Ql _"
5493 start of a collapsed thread.
5495 an uncollapsed thread (TODO ignored for now).
5499 classified as possible spam.
5505 Specifies a list of recipients to which a blind carbon copy of each
5506 outgoing message will be sent automatically.
5510 Specifies a list of recipients to which a carbon copy of each outgoing
5511 message will be sent automatically.
5515 \*(BO Causes threads to be collapsed automatically when threaded mode
5522 \*(BO Causes the delete command to behave like
5524 thus, after deleting a message the next one will be typed automatically.
5528 \*(BO\*(OB Causes threaded mode (see the
5530 command) to be entered automatically when a folder is opened.
5532 .Ql autosort=thread .
5536 Causes sorted mode (see the
5538 command) to be entered automatically with the value of this option as
5539 sorting method when a folder is opened, e.g.,
5540 .Ql set autosort=thread .
5544 \*(BO Enables the substitution of
5546 by the contents of the last command line in shell escapes.
5549 .It Va batch-exit-on-error
5550 \*(BO If the batch mode has been enabled via the
5552 command line option, then this variable will be consulted whenever \*(UA
5553 completes one operation (returns to the command prompt); if it is set
5554 then \*(UA will terminate if the last operation generated an error.
5558 \*(BO Causes automatic display of a header summary after executing a
5564 \*(BO Sets some cosmetical features to traditional BSD style;
5565 has the same affect as setting
5567 and all other variables prefixed with
5569 it also changes the meaning of the \*(UA specific
5572 escape sequence and changes behaviour of
5574 (which doesn't exist in BSD).
5578 \*(BO Changes the letters shown in the first column of a header
5579 summary to traditional BSD style.
5583 \*(BO Changes the display of columns in a header summary to traditional
5588 \*(BO Changes some informational messages to traditional BSD style.
5594 field to appear immediately after the
5596 field in message headers and with the
5598 .Sx "TILDE ESCAPES" .
5602 The value that should appear in the
5606 MIME header fields when no character set conversion of the message data
5608 This defaults to US-ASCII, and the chosen character set should be
5609 US-ASCII compatible.
5613 \*(OP The default 8-bit character set that is used as an implicit last
5614 member of the variable
5616 This defaults to UTF-8.
5617 If no character set conversion capabilities are available in \*(UA then
5618 the only supported character set is
5620 Refer to the section
5621 .Sx "Character sets"
5622 for the complete picture of character set conversion in \*(UA.
5625 .It Va charset-unknown-8bit
5626 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5628 the content of a mail message by using a character set with the name
5630 Because of the unclassified nature of this character set \*(UA will not
5631 be capable to convert this character set to any other character set.
5632 If this variable is set any message part which uses the character set
5634 is assumed to really be in the character set given in the value,
5635 otherwise the (final) value of
5637 is used for this purpose.
5639 This variable will also be taken into account if a MIME type (see
5640 .Sx "The mime.types files" )
5641 of a MIME message part that uses the
5643 character set is forcefully treated as text.
5647 The default value for the
5652 .It Va colour-disable
5653 \*(BO\*(OP Forcefully disable usage of colours.
5654 Also see the section
5655 .Sx "Coloured display" .
5659 \*(BO\*(OP Wether colour shall be used for output that is paged through
5661 Note that pagers may need special flags, e.g.,
5669 in order to support colours.
5670 Often doing manual adjustments is unnecessary since \*(UA may perform
5671 adjustments dependend on the value of the environment variable
5673 (see there for more).
5677 In a(n interactive) terminal session, then if this valued option is set
5678 it'll be used as a threshold to determine how many lines the given
5679 output has to span before it will be displayed via the configured
5683 can be forced by setting this to the value
5685 setting it without a value will deduce the current height of the
5686 terminal screen to compute the treshold (see
5694 \*(OB A variable counterpart of the
5696 command (see there for documentation), interpreted as a comma-separated
5697 list of custom headers to be injected, to include commas in the header
5698 bodies escape them with backslash, e.g.:
5700 .Dl set customhdr='Hdr1: Body1-1\e, Body1-2, Hdr2: Body2'
5706 the message date, if any is to be displayed according to the format of
5708 is by default taken from the
5710 line of the message.
5711 If this variable is set the date as given in the
5713 header field is used instead, converted to local time.
5714 To control the display format of the date assign a valid
5719 format should not be used, because \*(UA doesn't take embedded newlines
5720 into account when calculating how many lines fit onto the screen.)
5722 .Va datefield-markout-older .
5725 .It Va datefield-markout-older
5726 This option, when set in addition to
5730 messages (concept is rather comparable to the
5732 option of the POSIX utility
5734 The content interpretation is identical to
5739 \*(BO Enables debug messages and obsoletion warnings, disables the
5740 actual delivery of messages and also implies
5746 .It Va disposition-notification-send
5748 .Ql Disposition-Notification-To:
5749 header (RFC 3798) with the message.
5753 .\" TODO .It Va disposition-notification-send-HOST
5755 .\".Va disposition-notification-send
5756 .\" for SMTP accounts on a specific host.
5757 .\" TODO .It Va disposition-notification-send-USER@HOST
5759 .\".Va disposition-notification-send
5760 .\"for a specific account.
5764 \*(BO When dot is set, a period
5766 on a line by itself during message input in (interactive) compose mode
5767 will be treated as end-of-message (in addition to the normal end-of-file
5776 .It Va dotlock-ignore-error
5777 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5778 mailboxes (see the command
5780 will be protected with so-called dotlock files\(emthe traditional mail
5781 spool file locking method\(emin addition to system file locking.
5782 Because \*(UA ships with a privilege-separated dotlock creation program
5783 that should always be able to create such a dotlock file there is no
5784 good reason to ignore dotlock file creation errors, and thus these are
5785 fatal unless this variable is set.
5789 \*(BO If this variable is set then the editor is started automatically
5790 when a message is composed in interactive mode, as if the
5796 variable is implied for this automatically spawned editor session.
5800 \*(BO When a message is edited while being composed,
5801 its header is included in the editable text.
5811 fields are accepted within the header, other fields are ignored.
5815 \*(BO When entering interactive mode \*(UA normally writes
5816 .Dq \&No mail for user
5817 and exits immediately if a mailbox is empty or doesn't exist.
5818 If this option is set \*(UA starts even with an empty or nonexistent
5819 mailbox (the latter behaviour furtherly depends upon
5825 Suggestion for the MIME encoding to use in outgoing text messages
5827 Valid values are the default
5828 .Ql quoted-printable ,
5833 may cause problems when transferring mail messages over channels that
5834 are not ESMTP (RFC 1869) compliant.
5835 If there is no need to encode a message,
5837 transfer mode is always used regardless of this variable.
5838 Binary data is always encoded as
5843 If defined, the first character of this option
5844 gives the character to use in place of
5847 .Sx "TILDE ESCAPES" .
5851 If not set then file and command pipeline targets are not allowed,
5852 and any such address will be filtered out, giving a warning message.
5853 If set without a value then all possible recipient address
5854 specifications will be accepted \(en see the section
5855 .Sx "On sending mail, and non-interactive mode"
5857 To accept them, but only in interactive mode, or when tilde commands
5858 were enabled explicitly by using one of the command line options
5862 set this to the (case-insensitive) value
5864 (note right now this is actually like setting
5865 .Ql restrict,-all,+name,+addr ) .
5867 In fact the value is interpreted as a comma-separated list of values.
5870 then the existence of disallowed specifications is treated as a hard
5871 send error instead of only filtering them out.
5872 The remaining values specify wether a specific type of recipient
5873 address specification is allowed (optionally indicated by a plus sign
5875 prefix) or disallowed (prefixed with a hyphen
5879 addresses all possible address specifications,
5883 command pipeline targets,
5885 plain user names and (MTA) aliases (\*(OB
5887 may be used as an alternative syntax to
5892 These kind of values are interpreted in the given order, so that
5893 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5894 will cause hard errors for any non-network address recipient address
5895 unless \*(UA is in interactive mode or has been started with the
5899 command line option; in the latter case(s) any address may be used, then.
5903 Unless this variable is set additional mail-transfer-agent (MTA)
5904 arguments from the command line, as can be given after a
5906 separator, are ignored due to safety reasons.
5907 However, if set to the special (case-insensitive) value
5909 then the presence of additional MTA arguments is treated as a hard
5910 error that causes \*(UA to exit with failure status.
5911 A lesser strict variant is the otherwise identical
5913 which does accept such arguments in interactive mode, or if tilde
5914 commands were enabled explicitly by using one of the command line options
5921 \*(RO Information on the features compiled into \*(UA \(en the content
5922 of this variable is identical to the output of the command
5927 \*(BO This option reverses the meanings of a set of reply commands,
5928 turning the lowercase variants, which by default address all recipients
5929 included in the header of a message
5930 .Pf ( Ic reply , respond , followup )
5931 into the uppercase variants, which by default address the sender only
5932 .Pf ( Ic Reply , Respond , Followup )
5935 .Ic replysender , respondsender , followupsender
5937 .Ic replyall , respondall , followupall
5938 are not affected by the current setting of
5943 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5944 It is possible to install file hooks which will be used by the
5946 command in order to be able to transparently handle (through an
5947 intermediate temporary file) files with specific
5949 s: the variable values can include shell snippets and are expected to
5950 write data to standard output / read data from standard input,
5952 \*(ID The variables may not be changed while there is a mailbox
5954 .Bd -literal -offset indent
5955 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5956 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5957 record=+null-sent.xy
5962 The default path under which mailboxes are to be saved:
5963 file names that begin with the plus-sign
5965 will be expanded by prefixing them with the value of this variable.
5966 The same special syntax conventions as documented for the
5968 command may be used; if the non-empty value doesn't start with a slash
5972 will be prefixed automatically.
5973 If unset or the empty string any
5975 prefixing file names will remain unexpanded.
5979 This variable can be set to the name of a
5981 macro which will be called whenever a
5984 The macro will also be invoked when new mail arrives,
5985 but message lists for commands executed from the macro
5986 only include newly arrived messages then.
5988 are activated by default in a folder hook, causing the covered settings
5989 to be reverted once the folder is left again.
5992 Macro behaviour, including option localization, will change in v15.
5993 Please be aware of that and possibly embed a version check in a resource
5997 .It Va folder-hook-FOLDER
6002 Unlike other folder specifications, the fully expanded name of a folder,
6003 without metacharacters, is used to avoid ambiguities.
6004 However, if the mailbox resides under
6008 specification is tried in addition, e.g., if
6012 (and thus relative to the user's home directory) then
6013 .Pa /home/usr1/mail/sent
6015 .Ql folder-hook-/home/usr1/mail/sent
6016 first, but then followed by
6017 .Ql folder-hook-+sent .
6021 \*(BO Controls wether a
6022 .Ql Mail-Followup-To:
6023 header is generated when sending messages to known mailing lists.
6025 .Va followup-to-honour
6027 .Ic mlist , mlsubscribe , reply
6032 .It Va followup-to-honour
6034 .Ql Mail-Followup-To:
6035 header is honoured when group-replying to a message via
6039 This is a quadoption; if set without a value it defaults to
6049 .It Va forward-as-attachment
6050 \*(BO Original messages are normally sent as inline text with the
6053 and only the first part of a multipart message is included.
6054 With this option messages are sent as unmodified MIME
6056 attachments with all of their parts included.
6060 The address (or a list of addresses) to put into the
6062 field of the message header, quoting RFC 5322:
6063 the author(s) of the message, that is, the mailbox(es) of the person(s)
6064 or system(s) responsible for the writing of the message.
6065 If replying to messages these addresses are handled as if they were in
6069 If the machine's hostname is not valid at the Internet (for example at
6070 a dialup machine) then either this variable or
6075 adds even more fine-tuning capabilities),
6079 contains more than one address,
6082 variable is required (according to the standard RFC 5322).
6086 \*(BO When replying to or forwarding a message \*(UA normally removes
6087 the comment and name parts of email addresses.
6088 If this variable is set such stripping is not performed,
6089 and comments, names etc. are retained.
6093 The string to put before the text of a message with the
6097 .Va forward-as-attachment
6100 .Dq -------- Original Message --------
6101 if unset; No heading is put if it is set to the empty string.
6105 \*(BO Causes the header summary to be written at startup and after
6106 commands that affect the number of messages or the order of messages in
6107 the current folder; enabled by default.
6108 The command line option
6116 A format string to use for the summary of
6118 similar to the ones used for
6121 Format specifiers in the given string start with a percent character
6123 and may be followed by an optional decimal number indicating the field
6124 width \(em if that is negative, the field is to be left-aligned.
6125 Valid format specifiers are:
6128 .Bl -tag -compact -offset indent -width "_%%_"
6130 A plain percent character.
6133 a space character but for the current message
6135 for which it expands to
6139 a space character but for the current message
6141 for which it expands to
6144 \*(OP The spam score of the message, as has been classified via the
6147 Shows only a replacement character if there is no spam support.
6149 Message attribute character (status flag); the actual content can be
6153 The date when the message was received, or the date found in the
6157 variable is set (optionally to a date display format string).
6159 The indenting level in threaded mode.
6161 The address of the message sender.
6163 The message thread tree structure.
6164 (Note that this format doesn't support a field width.)
6166 The number of lines of the message, if available.
6170 The number of octets (bytes) in the message, if available.
6172 Message subject (if any).
6174 Message subject (if any) in double quotes.
6176 Message recipient flags: is the addressee of the message a known or
6177 subscribed mailing list \(en see
6182 The position in threaded/sorted order.
6186 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
6188 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
6199 .It Va headline-bidi
6200 Bidirectional text requires special treatment when displaying headers,
6201 because numbers (in dates or for file sizes etc.) will not affect the
6202 current text direction, in effect resulting in ugly line layouts when
6203 arabic or other right-to-left text is to be displayed.
6204 On the other hand only a minority of terminals is capable to correctly
6205 handle direction changes, so that user interaction is necessary for
6207 Note that extended host system support is required nonetheless, e.g.,
6208 detection of the terminal character set is one precondition;
6209 and this feature only works in an Unicode (i.e., UTF-8) locale.
6211 In general setting this variable will cause \*(UA to encapsulate text
6212 fields that may occur when displaying
6214 (and some other fields, like dynamic expansions in
6216 with special Unicode control sequences;
6217 it is possible to fine-tune the terminal support level by assigning
6219 no value (or any value other than
6224 will make \*(UA assume that the terminal is capable to properly deal
6225 with Unicode version 6.3, in which case text is embedded in a pair of
6226 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6228 In addition no space on the line is reserved for these characters.
6230 Weaker support is chosen by using the value
6232 (Unicode 6.3, but reserve the room of two spaces for writing the control
6233 sequences onto the line).
6238 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6239 again reserves room for two spaces in addition.
6243 \*(OP If a line editor is available then this can be set to
6244 name the (expandable) path of the location of a permanent history file.
6247 .It Va history-gabby
6248 \*(BO\*(OP Add more entries to the history as is normally done.
6251 .It Va history-gabby-persist
6252 \*(BO\*(OP \*(UA's own MLE will not save the additional
6254 entries in persistent storage unless this variable is set.
6255 On the other hand it will not loose the knowledge of wether a persistent
6256 entry was gabby or not.
6262 \*(OP If a line editor is available this value restricts the
6263 amount of history entries that are saved into a set and valid
6265 A value of less than 0 disables this feature;
6266 note that loading and incorporation of
6268 upon program startup can also be suppressed by doing this.
6269 If unset or 0, a default value will be used.
6270 Dependent on the available line editor this will also define the
6271 number of history entries in memory;
6272 it is also editor-specific wether runtime updates of this value will be
6277 \*(BO This option is used to hold messages in the system
6279 box, and it is set by default.
6283 Use this string as hostname when expanding local addresses instead of
6284 the value obtained from
6295 transport is not used then it is normally the responsibility of the MTA
6296 to create these fields, \*(IN in conjunction with
6300 also influences the results;
6301 you should produce some test messages with the desired combination of
6310 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
6311 names according to the rules of IDNA (internationalized domain names
6313 Since the IDNA code assumes that domain names are specified with the
6315 character set, an UTF-8 locale charset is required to represent all
6316 possible international domain names (before conversion, that is).
6320 \*(BO Ignore interrupt signals from the terminal while entering
6321 messages; instead echo them as
6323 characters and discard the current line.
6327 \*(BO Ignore end-of-file conditions
6328 .Pf ( Ql control-D )
6329 in compose mode on message input and in interactive command input.
6330 If set an interactive command input session can only be left by
6331 explicitly using one of the commands
6335 and message input in compose mode can only be terminated by entering
6338 on a line by itself or by using the
6340 .Sx "TILDE ESCAPES" ;
6342 overrides a setting of
6354 option for indenting messages,
6355 in place of the normal tabulator character
6357 which is the default.
6358 Be sure to quote the value if it contains spaces or tabs.
6362 \*(BO If set, an empty mailbox file is not removed.
6363 This may improve the interoperability with other mail user agents
6364 when using a common folder directory, and prevents malicious users
6365 from creating fake mailboxes in a world-writable spool directory.
6366 Note this only applies to local regular (MBOX) files, other mailbox
6367 types will never be removed.
6370 .It Va keep-content-length
6371 \*(BO When (editing messages and) writing
6373 mailbox files \*(UA can be told to keep the
6377 header fields that some MUAs generate by setting this variable.
6378 Since \*(UA does neither use nor update these non-standardized header
6379 fields (which in itself shows one of their conceptual problems),
6380 stripping them should increase interoperability in between MUAs that
6381 work with with same mailbox files.
6382 Note that, if this is not set but
6383 .Va writebackedited ,
6384 as below, is, a possibly performed automatic stripping of these header
6385 fields already marks the message as being modified.
6389 \*(BO When a message is saved it is usually discarded from the
6390 originating folder when \*(UA is quit.
6391 Setting this option causes all saved message to be retained.
6394 .It Va line-editor-disable
6395 \*(BO Turn off any enhanced line editing capabilities (see
6396 .Sx "On terminal control and line editor"
6401 \*(BO When a message is replied to and this variable is set,
6402 it is marked as having been answered.
6403 This mark has no technical meaning in the mail system;
6404 it just causes messages to be marked in the header summary,
6405 and makes them specially addressable.
6409 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6411 Messages which are fetched over the network or from within already
6412 existing Maildir (or any non-MBOX) mailboxes may require so-called
6414 quoting (insertion of additional
6416 characters to prevent line content misinterpretation) to be applied in
6417 order to be storable in MBOX mailboxes, however, dependent on the
6418 circumspection of the message producer.
6419 (E.g., \*(UA itself will, when newly generating messages, choose a
6420 .Pf Content-Transfer- Va encoding
6421 that prevents the necessity for such quoting \(en a necessary
6422 precondition to ensure message checksums won't change.)
6424 By default \*(UA will perform this
6426 quoting in a way that results in a MBOX file that is compatible with
6427 the POSIX MBOX layout, which means that, in order not to exceed the
6428 capabilities of simple applications, many more
6430 lines get quoted (thus modified) than necessary according to RFC 4155.
6431 Set this option to instead generate MBOX files which comply to RFC 4155.
6435 \*(BO Internal development variable.
6438 .It Va message-id-disable
6439 \*(BO By setting this option the generation of
6441 can be completely suppressed, effectively leaving this task up to the
6442 mail-transfer-agent (MTA) or the SMTP server.
6443 (According to RFC 5321 your SMTP server is not required to add this
6444 field by itself, so you should ensure that it accepts messages without a
6448 .It Va message-inject-head
6449 A string to put at the beginning of each new message.
6450 The escape sequences tabulator
6457 .It Va message-inject-tail
6458 A string to put at the end of each new message.
6459 The escape sequences tabulator
6467 \*(BO Usually, when an
6469 expansion contains the sender, the sender is removed from the expansion.
6470 Setting this option suppresses these removals.
6475 option to be passed to mail-transfer-agents (MTAs);
6476 though most of the modern MTAs don't (no longer) document this flag, no
6477 MTA is known which doesn't support it (for historical compatibility).
6480 .It Va mime-allow-text-controls
6481 \*(BO When sending messages, each part of the message is MIME-inspected
6482 in order to classify the
6485 .Ql Content-Transfer-Encoding:
6488 that is required to send this part over mail transport, i.e.,
6489 a computation rather similar to what the
6491 command produces when used with the
6495 This classification however treats text files which are encoded in
6496 UTF-16 (seen for HTML files) and similar character sets as binary
6497 octet-streams, forcefully changing any
6502 .Ql application/octet-stream :
6503 If that actually happens a yet unset charset MIME parameter is set to
6505 effectively making it impossible for the receiving MUA to automatically
6506 interpret the contents of the part.
6508 If this option is set, and the data was unambiguously identified as text
6509 data at first glance (by a
6513 file extension), then the original
6515 will not be overwritten.
6518 .It Va mime-alternative-favour-rich
6519 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6520 HTML) will be preferred in favour of included plain text versions when
6521 displaying messages, provided that a handler exists which produces
6522 output that can be (re)integrated into \*(UA's normal visual display.
6523 (E.g., at the time of this writing some newsletters ship their full
6524 content only in the rich HTML part, whereas the plain text part only
6525 contains topic subjects.)
6528 .It Va mime-counter-evidence
6531 field is used to decide how to handle MIME parts.
6532 Some MUAs however don't use
6534 or a similar mechanism to correctly classify content, but simply specify
6535 .Ql application/octet-stream ,
6536 even for plain text attachments like
6538 If this variable is set then \*(UA will try to classify such MIME
6539 message parts on its own, if possible, for example via a possibly
6540 existent attachment filename.
6541 A non-empty value may also be given, in which case a number is expected,
6542 actually a carrier of bits.
6543 Creating the bit-carrying number is a simple addition:
6544 .Bd -literal -offset indent
6545 ? !echo Value should be set to $((2 + 4 + 8))
6546 Value should be set to 14
6549 .Bl -bullet -compact
6551 If bit two is set (2) then the detected
6553 content-type will be carried along with the message and be used for
6555 .Va pipe-TYPE/SUBTYPE
6556 is responsible for the MIME part, shall that question arise;
6557 when displaying such a MIME part the part-info will indicate the
6558 overridden content-type by showing a plus-sign
6561 If bit three is set (4) then the counter-evidence is always produced
6562 and a positive result will be used as the MIME type, even forcefully
6563 overriding the parts given MIME type.
6565 If bit four is set (8) then as a last resort the actual content of
6566 .Ql application/octet-stream
6567 parts will be inspected, so that data which looks like plain text can be
6572 .It Va mimetypes-load-control
6573 This option can be used to control which of the
6575 databases are loaded by \*(UA, as furtherly described in the section
6576 .Sx "The mime.types files" .
6579 is part of the option value, then the user's personal
6581 file will be loaded (if it exists); likewise the letter
6583 controls loading of the system wide
6584 .Pa /etc/mime.types ;
6585 directives found in the user file take precedence, letter matching is
6587 If this option is not set \*(UA will try to load both files.
6588 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6589 but they will be matched last.
6591 More sources can be specified by using a different syntax: if the
6592 value string contains an equals sign
6594 then it is instead parsed as a comma-separated list of the described
6597 pairs; the given filenames will be expanded and loaded, and their
6598 content may use the extended syntax that is described in the section
6599 .Sx "The mime.types files" .
6600 Directives found in such files always take precedence (are prepended to
6601 the MIME type cache).
6604 .It Va NAIL_EXTRA_RC
6605 The name of an optional startup file to be read last.
6606 This variable has an effect only if it is set in any of the
6607 .Sx "Resource files" ,
6608 it is not imported from the environment.
6609 Use this file for commands that are not understood by other POSIX
6614 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6615 \*(BO\*(IN\*(OP Used to control usage of the users
6617 file for lookup of account credentials, as documented in the section
6618 .Sx "On URL syntax and credential lookup"
6622 .Sx "The .netrc file"
6623 documents the file format.
6627 If this variable has the value
6629 newly created local folders will be in Maildir format.
6633 Checks for new mail in the current folder each time the prompt is shown.
6634 A Maildir folder must be re-scanned to determine if new mail has arrived.
6635 If this variable is set to the special value
6637 then a Maildir folder will not be rescanned completely, but only
6638 timestamp changes are detected.
6642 .It Va on-compose-enter , on-compose-leave
6643 \*(ID Macro hooks which will be executed before compose mode is
6644 entered, and after composing has been finished, respectively.
6645 Please note that this interface is very likely to change in v15, and
6646 should therefore possibly even be seen as experimental.
6648 are by default enabled for these hooks, causing any setting to be
6649 forgotten after the message has been sent.
6650 The following variables will be set temporarily during execution of the
6653 .Bl -tag -compact -width ".It Va compose_subject"
6656 .It Va compose-sender
6658 .It Va compose-to , compose-cc , compose-bcc
6659 The list of receiver addresses as a space-separated list.
6660 .It Va compose-subject
6666 \*(BO Causes the filename given in the
6669 and the sender-based filenames for the
6673 commands to be interpreted relative to the directory given in the
6675 variable rather than to the current directory,
6676 unless it is set to an absolute pathname.
6680 \*(BO If set, each message feed through the command given for
6682 is followed by a formfeed character
6686 .It Va password-USER@HOST , password-HOST , password
6687 \*(IN Variable chain that sets a password, which is used in case none has
6688 been given in the protocol and account-specific URL;
6689 as a last resort \*(UA will ask for a password on the user's terminal if
6690 the authentication method requires a password.
6691 Specifying passwords in a startup file is generally a security risk;
6692 the file should be readable by the invoking user only.
6694 .It Va password-USER@HOST
6695 \*(OU (see the chain above for \*(IN)
6696 Set the password for
6700 If no such variable is defined for a host,
6701 the user will be asked for a password on standard input.
6702 Specifying passwords in a startup file is generally a security risk;
6703 the file should be readable by the invoking user only.
6707 \*(BO Send messages to the
6709 command without performing MIME and character set conversions.
6713 .It Va pipe-TYPE/SUBTYPE
6714 When a MIME message part of type
6716 (case-insensitive) is displayed or quoted,
6717 its text is filtered through the value of this variable interpreted as
6721 forces interpretation of the message part as plain text, e.g.,
6722 .Ql set pipe-application/xml=@
6723 will henceforth display XML
6725 (The same could also be achieved by adding a MIME type marker with the
6728 And \*(OPally MIME type handlers may be defined via
6729 .Sx "The Mailcap files"
6730 \(em corresponding flag strings are shown in parenthesis below.)
6735 can in fact be used to adjust usage and behaviour of a following shell
6736 command specification by appending trigger characters to it, e.g., the
6737 following hypothetical command specification could be used:
6738 .Bd -literal -offset indent
6739 set pipe-X/Y='@*!++=@vim ${NAIL_FILENAME_TEMPORARY}'
6743 .Bl -tag -compact -width ".It Ql __"
6745 Simply by using the special
6747 prefix the MIME type (shell command) handler will only be invoked to
6748 display or convert the MIME part if the message is addressed directly
6749 and alone by itself.
6750 Use this trigger to disable this and always invoke the handler
6751 .Pf ( Cd x-mailx-always ) .
6754 If set the handler will not be invoked when a message is to be quoted,
6755 but only when it will be displayed
6756 .Pf ( Cd x-mailx-noquote ) .
6759 The command will be run asynchronously, i.e., without blocking \*(UA,
6760 which may be a handy way to display a, e.g., PDF file while also
6761 continuing to read the mail message
6762 .Pf ( Cd x-mailx-async ) .
6763 Asynchronous execution implies
6767 The command must be run on an interactive terminal, \*(UA will
6768 temporarily release the terminal to it
6769 .Pf ( Cd needsterminal ) .
6770 This flag is mutual exclusive with
6772 will only be used in interactive mode and implies
6776 Request creation of a zero-sized temporary file, the absolute pathname
6777 of which will be made accessable via the environment variable
6778 .Ev NAIL_FILENAME_TEMPORARY
6779 .Pf ( Cd x-mailx-tmpfile ) .
6780 If this trigger is given twice then the file will be unlinked
6781 automatically by \*(UA when the command loop is entered again at latest
6782 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6783 (Don't use this for asynchronous handlers.)
6786 Normally the MIME part content is passed to the handler via standard
6787 input; if this flag is set then the data will instead be written into
6788 .Ev NAIL_FILENAME_TEMPORARY
6789 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6790 the creation of which is implied; note however that in order to cause
6791 deletion of the temporary file you still have to use two plus signs
6796 To avoid ambiguities with normal shell command content you can use
6797 another at-sign to forcefully terminate interpretation of remaining
6799 (Any character not in this list will have the same effect.)
6803 Some information about the MIME part to be displayed is embedded into
6804 the environment of the shell command:
6807 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6810 The MIME content-type of the part, if known, the empty string otherwise.
6813 .It Ev NAIL_CONTENT_EVIDENCE
6815 .Va mime-counter-evidence
6816 includes the carry-around-bit (2), then this will be set to the detected
6817 MIME content-type; not only then identical to
6818 .Ev \&\&NAIL_CONTENT
6822 .It Ev NAIL_FILENAME
6823 The filename, if any is set, the empty string otherwise.
6826 .It Ev NAIL_FILENAME_GENERATED
6830 .It Ev NAIL_FILENAME_TEMPORARY
6831 If temporary file creation has been requested through the command prefix
6832 this variable will be set and contain the absolute pathname of the
6837 The temporary directory that \*(UA uses.
6838 Usually identical to
6840 but guaranteed to be set and usable by child processes;
6841 to ensure the latter condition for
6848 .It Va pipe-EXTENSION
6849 This is identical to
6850 .Va pipe-TYPE/SUBTYPE
6853 (normalized to lowercase using character mappings of the ASCII charset)
6854 names a file extension, e.g.,
6856 Handlers registered using this method take precedence.
6859 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6860 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6861 The only possible value as of now is
6863 which is thus the default.
6866 .Mx Va pop3-bulk-load
6867 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6868 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6869 the messages, and only requests the message bodies on user request.
6870 For the POP3 protocol this means that the message headers will be
6872 If this option is set then \*(UA will download only complete messages
6873 from the given POP3 server(s) instead.
6875 .Mx Va pop3-keepalive
6876 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6877 \*(OP POP3 servers close the connection after a period of inactivity;
6878 the standard requires this to be at least 10 minutes,
6879 but practical experience may vary.
6880 Setting this variable to a numeric value greater than
6884 command to be sent each value seconds if no other operation is performed.
6887 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6888 \*(BO\*(OP Unless this variable is set the
6890 authentication method will be used when connecting to a POP3 server that
6894 is that the password is not sent in clear text over the wire and that
6895 only a single packet is sent for the user/password tuple.
6897 .Va pop3-no-apop-HOST
6900 .Mx Va pop3-use-starttls
6901 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6902 \*(BO\*(OP Causes \*(UA to issue a
6904 command to make an unencrypted POP3 session SSL/TLS encrypted.
6905 This functionality is not supported by all servers,
6906 and is not used if the session is already encrypted by the POP3S method.
6908 .Va pop3-use-starttls-HOST
6912 .It Va print-alternatives
6913 \*(BO When a MIME message part of type
6914 .Ql multipart/alternative
6915 is displayed and it contains a subpart of type
6917 other parts are normally discarded.
6918 Setting this variable causes all subparts to be displayed,
6919 just as if the surrounding part was of type
6920 .Ql multipart/mixed .
6924 The string shown when a command is accepted.
6925 Prompting may be prevented by setting this to the null string
6927 .Pf no Va prompt ) .
6928 If a value is assigned the following \*(UA specific additional sequences
6935 is set, in which case it expands to
6939 is the default value of
6942 which will expand to
6944 if the last command failed and to
6948 which will expand to the name of the currently active
6950 if any, and to the empty string otherwise, and
6952 which will expand to the name of the currently active mailbox.
6953 (Note that the prompt buffer is size-limited, excess is cut off.)
6959 to encapsulate the expansions of the
6963 escape sequences as necessary to correctly display bidirectional text,
6964 this is not true for the final string that makes up
6966 as such, i.e., real BIDI handling is not supported.
6970 \*(BO Suppresses the printing of the version when first invoked.
6974 If set, \*(UA starts a replying message with the original message
6975 prefixed by the value of the variable
6977 Normally, a heading consisting of
6978 .Dq Fromheaderfield wrote:
6979 is put before the quotation.
6984 variable, this heading is omitted.
6987 is assigned, the headers selected by the
6988 .Ic ignore Ns / Ns Ic retain
6989 commands are put above the message body,
6992 acts like an automatic
6998 is assigned, all headers are put above the message body and all MIME
6999 parts are included, making
7001 act like an automatic
7004 .Va quote-as-attachment .
7007 .It Va quote-as-attachment
7008 \*(BO Add the original message in its entirety as a
7010 MIME attachment when replying to a message.
7011 Note this works regardless of the setting of
7016 \*(OP Can be set in addition to
7018 Setting this turns on a more fancy quotation algorithm in that leading
7019 quotation characters are compressed and overlong lines are folded.
7021 can be set to either one or two (space separated) numeric values,
7022 which are interpreted as the maximum (goal) and the minimum line length,
7023 respectively, in a spirit rather equal to the
7025 program, but line-, not paragraph-based.
7026 If not set explicitly the minimum will reflect the goal algorithmically.
7027 The goal can't be smaller than the length of
7029 plus some additional pad.
7030 Necessary adjustments take place silently.
7033 .It Va recipients-in-cc
7034 \*(BO On group replies, specify only the sender of the original mail in
7036 and mention the other recipients in the secondary
7038 By default all recipients of the original mail will be addressed via
7043 If defined, gives the pathname of the folder used to record all outgoing
7045 If not defined, then outgoing mail is not saved.
7046 When saving to this folder fails the message is not sent,
7047 but instead saved to
7051 .It Va record-resent
7052 \*(BO If both this variable and the
7059 commands save messages to the
7061 folder as it is normally only done for newly composed messages.
7064 .It Va reply-in-same-charset
7065 \*(BO If this variable is set \*(UA first tries to use the same
7066 character set of the original message for replies.
7067 If this fails, the mechanism described in
7068 .Sx "Character sets"
7069 is evaluated as usual.
7072 .It Va reply_strings
7073 Can be set to a comma-separated list of (case-insensitive according to
7074 ASCII rules) strings which shall be recognized in addition to the
7077 reply message indicators \(en builtin are
7079 which is mandated by RFC 5322, as well as the german
7084 A list of addresses to put into the
7086 field of the message header.
7087 Members of this list are handled as if they were in the
7092 .It Va reply-to-honour
7095 header is honoured when replying to a message via
7099 This is a quadoption; if set without a value it defaults to
7103 .It Va rfc822-body-from_
7104 \*(BO This variable can be used to force displaying a so-called
7106 line for messages that are embedded into an envelope mail via the
7108 MIME mechanism, for more visual convenience.
7112 \*(BO Enable saving of (partial) messages in
7114 upon interrupt or delivery error.
7118 When \*(UA initially displays the message headers it determines the
7119 number to display by looking at the speed of the terminal.
7120 The faster the terminal, the more will be shown.
7121 This option specifies the number to use and overrides the calculation.
7122 This number is also used for scrolling with the
7125 Overall screen dimensions and pager usage is influenced by the
7126 environment variables
7134 .It Va searchheaders
7135 \*(BO Expand message-list specifiers in the form
7137 to all messages containing the substring
7141 The string search is case insensitive.
7145 \*(OP A comma-separated list of character set names that can be used in
7146 outgoing internet mail.
7147 The value of the variable
7149 is automatically appended to this list of character-sets.
7150 If no character set conversion capabilities are compiled into \*(UA then
7151 the only supported charset is
7154 .Va sendcharsets-else-ttycharset
7155 and refer to the section
7156 .Sx "Character sets"
7157 for the complete picture of character set conversion in \*(UA.
7160 .It Va sendcharsets-else-ttycharset
7161 \*(BO\*(OP If this variable is set, but
7163 is not, then \*(UA acts as if
7165 had been set to the value of the variable
7167 In effect this combination passes through the message data in the
7168 character set of the current locale (given that
7170 hasn't been set manually), i.e., without converting it to the
7172 fallback character set.
7173 Thus, mail message text will be in ISO-8859-1 encoding when send from
7174 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
7176 If no character set conversion capabilities are available in \*(UA then
7177 the only supported character set is
7182 An address that is put into the
7184 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
7185 responsible for the actual transmission of the message.
7186 This field should normally not be used unless the
7188 field contains more than one address, on which case it is required.
7191 address is handled as if it were in the
7197 To use an alternate mail transport agent (MTA),
7198 set this option to the full pathname of the program to use.
7199 It may be necessary to set
7200 .Va sendmail-progname
7203 The MTA will be passed command line arguments from several possible
7204 sources: from the variable
7205 .Va sendmail-arguments
7206 if set, from the command line if given and the variable
7209 Argument processing of the MTA will be terminated with a
7213 The otherwise occurring implicit usage of the following MTA command line
7214 arguments can be disabled by setting the boolean option
7215 .Va sendmail-no-default-arguments
7216 (which will also disable passing
7220 (for not treating a line with only a dot
7222 character as the end of input),
7230 option is set); in conjunction with the
7232 command line option \*(UA will also pass
7238 .It Va sendmail-arguments
7239 Arguments to pass through to the Mail-Transfer-Agent can be given via
7241 The content of this variable will be split up in a vector of arguments
7242 which will be joined onto other possible MTA options:
7244 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7247 .It Va sendmail-no-default-arguments
7248 \*(BO Unless this option is set \*(UA will pass some well known
7249 standard command line options to the defined
7251 program, see there for more.
7254 .It Va sendmail-progname
7255 Many systems use a so-called
7257 environment to ensure compatibility with
7259 This works by inspecting the name that was used to invoke the mail
7261 If this variable is set then the mailwrapper (the program that is
7262 actually executed when calling
7264 will treat its contents as that name.
7270 \*(BO When sending a message wait until the MTA (including the builtin
7271 SMTP one) exits before accepting further commands.
7273 with this variable set errors reported by the MTA will be recognizable!
7274 If the MTA returns a non-zero exit status,
7275 the exit status of \*(UA will also be non-zero.
7279 \*(BO Setting this option causes \*(UA to start at the last message
7280 instead of the first one when opening a mail folder.
7284 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7285 address in the header field summary and in message specifications.
7289 \*(BO Causes the recipient of the message to be shown in the header
7290 summary if the message was sent by the user.
7294 A string for use with the
7300 A string for use with the
7306 Must correspond to the name of a readable file if set.
7307 The file's content is then appended to each singlepart message
7308 and to the first part of each multipart message.
7309 Be warned that there is no possibility to edit the signature for an
7313 .It Va skipemptybody
7314 \*(BO If an outgoing message does not contain any text in its first or
7315 only message part, do not send it but discard it silently (see also the
7321 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7322 Enhanced Mail) format for verification of S/MIME signed messages.
7325 .It Va smime-ca-file
7326 \*(OP Specifies a file with CA certificates in PEM format for
7327 verification of S/MIME signed messages.
7330 .It Va smime-cipher-USER@HOST , smime-cipher
7331 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7332 messages (for the specified account).
7333 RFC 5751 mandates a default of
7336 Possible values are (case-insensitive and) in decreasing cipher strength:
7344 (DES EDE3 CBC, 168 bits; default if
7346 isn't available) and
7350 The actually available cipher algorithms depend on the cryptographic
7351 library that \*(UA uses.
7352 \*(OP Support for more cipher algorithms may be available through
7353 dynamic loading via, e.g.,
7354 .Xr EVP_get_cipherbyname 3
7355 (OpenSSL) if \*(UA has been compiled to support this.
7358 .It Va smime-crl-dir
7359 \*(OP Specifies a directory that contains files with CRLs in PEM format
7360 to use when verifying S/MIME messages.
7363 .It Va smime-crl-file
7364 \*(OP Specifies a file that contains a CRL in PEM format to use when
7365 verifying S/MIME messages.
7368 .It Va smime-encrypt-USER@HOST
7369 \*(OP If this variable is set, messages send to the given receiver are
7370 encrypted before sending.
7371 The value of the variable must be set to the name of a file that
7372 contains a certificate in PEM format.
7374 If a message is sent to multiple recipients,
7375 each of them for whom a corresponding variable is set will receive an
7376 individually encrypted message;
7377 other recipients will continue to receive the message in plain text
7379 .Va smime-force-encryption
7381 It is recommended to sign encrypted messages, i.e., to also set the
7386 .It Va smime-force-encryption
7387 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7390 .It Va smime-no-default-ca
7391 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7396 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7397 and include the user's certificate as a MIME attachment.
7398 Signing a message enables a recipient to verify that the sender used
7399 a valid certificate,
7400 that the email addresses in the certificate match those in the message
7401 header and that the message content has not been altered.
7402 It does not change the message text,
7403 and people will be able to read the message as usual.
7405 .Va smime-sign-cert , smime-sign-include-certs
7407 .Va smime-sign-message-digest .
7409 .Mx Va smime-sign-cert
7410 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7411 \*(OP Points to a file in PEM format.
7412 For the purpose of signing and decryption this file needs to contain the
7413 user's private key as well as his certificate.
7417 is always derived from the value of
7419 (or, if that contains multiple addresses,
7421 For the purpose of encryption the recipient's public encryption key
7422 (certificate) is expected; the command
7424 can be used to save certificates of signed messages (the section
7425 .Sx "Signed and encrypted messages with S/MIME"
7426 gives some details).
7427 This mode of operation is usually driven by the specialized form.
7429 When decrypting messages the account is derived from the recipient
7434 of the message, which are searched for addresses for which such
7436 \*(UA always uses the first address that matches,
7437 so if the same message is sent to more than one of the user's addresses
7438 using different encryption keys, decryption might fail.
7440 .Mx Va smime-sign-include-certs
7441 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7442 \*(OP If used, this is supposed to a consist of a comma-separated list
7443 of files, each of which containing a single certificate in PEM format to
7444 be included in the S/MIME message in addition to the
7447 This is most useful for long certificate chains if it is desired to aid
7448 the receiving party's verification process.
7449 Note that top level certificates may also be included in the chain but
7450 don't play a role for verification.
7452 .Va smime-sign-cert .
7453 Remember that for this
7455 refers to the variable
7457 (or, if that contains multiple addresses,
7460 .Mx Va smime-sign-message-digest
7461 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7462 \*(OP Specifies the message digest to use when signing S/MIME messages.
7463 RFC 5751 mandates a default of
7465 Possible values are (case-insensitive and) in decreasing cipher strength:
7473 The actually available message digest algorithms depend on the
7474 cryptographic library that \*(UA uses.
7475 \*(OP Support for more message digest algorithms may be available
7476 through dynamic loading via, e.g.,
7477 .Xr EVP_get_digestbyname 3
7478 (OpenSSL) if \*(UA has been compiled to support this.
7479 Remember that for this
7481 refers to the variable
7483 (or, if that contains multiple addresses,
7489 \*(OP Normally \*(UA invokes the program defined via
7491 to transfer messages, as described in
7492 .Sx "On sending mail, and non-interactive mode" .
7495 variable will instead cause SMTP network connections be made to the
7496 server specified therein in order to directly submit the message.
7497 \*(UA knows about three different
7498 .Dq SMTP protocols :
7500 .Bl -bullet -compact
7502 The plain SMTP protocol (RFC 5321) that normally lives on the
7503 server port 25 and requires setting the
7504 .Va smtp-use-starttls
7505 variable to enter a SSL/TLS encrypted session state.
7506 Assign a value like \*(IN
7507 .Ql [smtp://][user[:password]@]server[:port]
7509 .Ql [smtp://]server[:port] )
7510 to choose this protocol.
7512 Then the so-called SMTPS which is supposed to live on server port 465
7513 and is automatically SSL/TLS secured.
7514 Unfortunately it never became a standardized protocol and may thus not
7515 be supported by your hosts network service database
7516 \(en in fact the port number has already been reassigned to other
7519 SMTPS is nonetheless a commonly offered protocol and thus can be
7520 chosen by assigning a value like \*(IN
7521 .Ql smtps://[user[:password]@]server[:port]
7523 .Ql smtps://server[:port] ) ;
7524 due to the mentioned problems it is usually necessary to explicitly
7529 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7530 lives on server port 587 and is practically identically to the SMTP
7531 protocol from \*(UA's point of view beside that; it requires setting the
7532 .Va smtp-use-starttls
7533 variable to enter a SSL/TLS secured session state.
7534 Assign a value like \*(IN
7535 .Ql submission://[user[:password]@]server[:port]
7537 .Ql submission://server[:port] ) .
7540 For more on credentials etc. please see
7541 .Sx "On URL syntax and credential lookup" .
7542 The SMTP transfer is executed in a child process, which runs
7543 asynchronously unless either the
7548 If it receives a TERM signal, it will abort and save the message to
7553 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7554 \*(OP Variable chain that sets the SMTP authentication method.
7561 as well as the \*(OPal methods
7567 method doesn't need any user credentials,
7569 requires a user name and all other methods require a user name and
7577 .Va smtp-auth-password
7579 .Va smtp-auth-user ) .
7584 .Va smtp-auth-USER@HOST :
7585 may override dependend on sender address in the variable
7588 .It Va smtp-auth-password
7589 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7590 If the authentication method requires a password, but neither
7591 .Va smtp-auth-password
7593 .Va smtp-auth-password-USER@HOST
7595 \*(UA will ask for a password on the user's terminal.
7597 .It Va smtp-auth-password-USER@HOST
7599 .Va smtp-auth-password
7600 for specific values of sender addresses, dependent upon the variable
7603 .It Va smtp-auth-user
7604 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7605 If the authentication method requires a user name, but neither
7608 .Va smtp-auth-user-USER@HOST
7610 \*(UA will ask for a user name on the user's terminal.
7612 .It Va smtp-auth-user-USER@HOST
7615 for specific values of sender addresses, dependent upon the variable
7619 .It Va smtp-hostname
7620 \*(IN Normally \*(UA uses the variable
7622 to derive the necessary
7624 information to issue a
7629 can be used to use the
7631 from the SMTP account
7638 from the content of this variable (or, if that is the empty string,
7640 or the local hostname as a last resort).
7641 This often allows using an address that is itself valid but hosted by
7642 a provider other than which (in
7644 is about to send the message.
7645 Setting this variable also influences the generated
7648 .Mx Va smtp-use-starttls
7649 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7650 \*(BO\*(OP Causes \*(UA to issue a
7652 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7653 transport layer security.
7657 .It Va spam-interface
7658 \*(OP In order to use any of the spam-related commands (like, e.g.,
7660 the desired spam interface must be defined by setting this variable.
7661 Please refer to the manual section
7663 for the complete picture of spam handling in \*(UA.
7664 All or none of the following interfaces may be available:
7666 .Bl -tag -width ".It Ql _ilte_"
7672 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7674 Different to the generic filter interface \*(UA will automatically add
7675 the correct arguments for a given command and has the necessary
7676 knowledge to parse the program's output.
7679 will have been compiled into the \*(UA binary if
7684 Shall it be necessary to define a specific connection type (rather than
7685 using a configuration file for that), the variable
7687 can be used as in, e.g.,
7688 .Ql -d server.example.com -p 783 .
7689 It is also possible to specify a per-user configuration via
7691 Note that this interface doesn't inspect the
7693 flag of a message for the command
7697 \*(UA will directly communicate with the
7703 stream socket as specified in
7705 It is possible to specify a per-user configuration via
7709 generic spam filter support via freely configurable hooks.
7710 This interface is ment for programs like
7714 and requires according behaviour in respect to the hooks' exit
7715 status for at least the command
7718 meaning a message is spam,
7722 for unsure and any other return value indicating a hard error);
7723 since the hooks can include shell code snippets diverting behaviour
7724 can be intercepted as necessary.
7726 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7729 .Va spamfilter-spam ;
7732 contains examples for some programs.
7733 The process environment of the hooks will have the variables
7734 .Ev NAIL_TMPDIR , TMPDIR
7736 .Ev NAIL_FILENAME_GENERATED
7738 Note that spam score support for
7740 isn't supported unless the \*(OPtional regular expression support is
7742 .Va spamfilter-rate-scanscore
7749 \*(OP Messages that exceed this size won't be passed through to the
7751 .Va spam-interface .
7752 If unset or 0, the default of 420000 bytes is used.
7755 .It Va spamc-command
7756 \*(OP The path to the
7760 .Va spam-interface .
7761 Note that the path is not expanded, but used
7763 A fallback path will have been compiled into the \*(UA binary if the
7764 executable had been found during compilation.
7767 .It Va spamc-arguments
7768 \*(OP Even though \*(UA deals with most arguments for the
7771 automatically, it may at least sometimes be desirable to specifiy
7772 connection-related ones via this variable, e.g.,
7773 .Ql -d server.example.com -p 783 .
7777 \*(OP Specify a username for per-user configuration files for the
7779 .Va spam-interface .
7780 If this is set to the empty string then \*(UA will use the name of the
7786 \*(OP Specify the path of the
7788 domain socket on which
7790 listens for connections for the
7792 .Va spam-interface .
7793 Note that the path is not expanded, but used
7798 \*(OP Specify a username for per-user configuration files for the
7800 .Va spam-interface .
7801 If this is set to the empty string then \*(UA will use the name of the
7810 .It Va spamfilter-ham , spamfilter-noham , \
7811 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7812 \*(OP Command and argument hooks for the
7814 .Va spam-interface .
7817 contains examples for some programs.
7820 .It Va spamfilter-rate-scanscore
7821 \*(OP Because of the generic nature of the
7824 spam scores are not supported for it by default, but if the \*(OPtional
7825 regular expression support is available then setting this variable can
7826 be used to overcome this restriction.
7827 It is interpreted as follows: first a number (digits) is parsed that
7828 must be followed by a semicolon
7830 and an extended regular expression.
7831 Then the latter is used to parse the first output line of the
7833 hook, and, in case the evaluation is successful, the group that has been
7834 specified via the number is interpreted as a floating point scan score.
7838 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7839 Enhanced Mail) for verification of of SSL/TLS server certificates.
7841 .Xr SSL_CTX_load_verify_locations 3
7842 for more information.
7846 \*(OP Specifies a file with CA certificates in PEM format for
7847 verification of SSL/TLS server certificates.
7849 .Xr SSL_CTX_load_verify_locations 3
7850 for more information.
7853 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7854 \*(OP Variable chain that sets the file name for a SSL/TLS client
7855 certificate required by some servers.
7856 This is a direct interface to the
7860 function of the OpenSSL library, if available.
7862 .Mx Va ssl-cipher-list
7863 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7864 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7865 This is a direct interface to the
7869 function of the OpenSSL library, if available; see
7871 for more information.
7872 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7874 specific cipher (protocol standards ship with a list of acceptable
7875 ciphers), possibly cramped to what the actually used SSL/TLS library
7876 supports \(en the manual section
7877 .Sx "An example configuration"
7878 also contains a SSL/TLS use case.
7881 .It Va ssl-config-file
7882 \*(OP If this variable is set \*(UA will call
7883 .Xr CONF_modules_load_file 3
7884 to allow OpenSSL to be configured according to the host system wide
7886 If a non-empty value is given then this will be used to specify the
7887 configuration file to be used instead of the global OpenSSL default;
7888 note that in this case it is an error if the file cannot be loaded.
7889 The application name will always be passed as
7894 \*(OP Specifies a file that contains a CRL in PEM format to use when
7895 verifying SSL/TLS server certificates.
7899 \*(OP Specifies a directory that contains files with CRLs in PEM format
7900 to use when verifying SSL/TLS server certificates.
7903 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7904 \*(OP Variable chain that sets the file name for the private key of
7905 a SSL/TLS client certificate.
7906 If unset, the name of the certificate file is used.
7907 The file is expected to be in PEM format.
7908 This is a direct interface to the
7912 function of the OpenSSL library, if available.
7915 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7917 \*(OB Please use the newer and more flexible
7919 instead: if both values are set,
7921 will take precedence!
7922 Can be set to the following values, the actually used
7924 specification to which it is mapped is shown in parenthesis:
7926 .Pf ( Ql -ALL, TLSv1.2 ) ,
7928 .Pf ( Ql -ALL, TLSv1.1 ) ,
7930 .Pf ( Ql -ALL, TLSv1 )
7933 .Pf ( Ql -ALL, SSLv3 ) ;
7938 and thus includes the SSLv3 protocol.
7939 Note that SSLv2 is no longer supported at all.
7942 .It Va ssl-no-default-ca
7943 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7947 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7948 \*(OP Specify the used SSL/TLS protocol.
7949 This is a direct interface to the
7953 function of the OpenSSL library, if available;
7954 otherwise an \*(UA internal parser is used which understands the
7955 following subset of (case-insensitive) command strings:
7961 as well as the special value
7963 Multiple specifications may be given via a comma-separated list which
7964 ignores any whitespace.
7967 plus prefix will enable a protocol, a
7969 minus prefix will disable it, so that
7971 will enable only the TLSv1.2 protocol.
7973 It depends upon the used TLS/SSL library which protocols are actually
7974 supported and which protocols are used if
7976 is not set, but note that SSLv2 is no longer supported at all and
7978 Especially for older protocols explicitly securing
7980 may be worthwile, see
7981 .Sx "An example configuration" .
7985 \*(OP Gives the pathname to an entropy daemon socket, see
7987 Not all SSL/TLS libraries support this.
7990 .It Va ssl-rand-file
7991 \*(OP Gives the filename to a file with random entropy data, see
7992 .Xr RAND_load_file 3 .
7993 If this variable is not set, or set to the empty string, or if the
7994 filename expansion failed, then
7995 .Xr RAND_file_name 3
7996 will be used to create the filename if, and only if,
7998 documents that the SSL PRNG is not yet sufficiently seeded.
7999 If \*(UA successfully seeded the SSL PRNG then it'll update the file via
8000 .Xr RAND_write_file 3 .
8001 This variable is only used if
8003 is not set (or not supported by the SSL/TLS library).
8006 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
8007 \*(OP Variable chain that sets the action to be performed if an error
8008 occurs during SSL/TLS server certificate validation.
8009 Valid (case-insensitive) values are
8011 (fail and close connection immediately),
8013 (ask whether to continue on standard input),
8015 (show a warning and continue),
8017 (do not perform validation).
8023 If only set without an assigned value, then this option inhibits the
8028 header fields that include obvious references to \*(UA.
8029 There are two pitfalls associated with this:
8030 First, the message id of outgoing messages is not known anymore.
8031 Second, an expert may still use the remaining information in the header
8032 to track down the originating mail user agent.
8037 suppression doesn't occur.
8042 (\*(OP) This specifies a comma-separated list of
8047 .Sx "On terminal control and line editor" ,
8048 escape commas with backslash) to be used to overwrite or define entries.
8050 that this variable will only be queried once at program startup and can
8051 thus only be specified in resource files or on the command line.
8054 String capabilities form
8056 pairs and are expected unless noted otherwise.
8057 Numerics have to be notated as
8059 where the number is expected in normal decimal notation.
8060 Finally, booleans don't have any value but indicate a true or false
8061 state simply by being defined or not; this indeed means that \*(UA
8062 doesn't support undefining a boolean that normally exists.
8063 The following example defines that the terminal has 256 colours:
8065 .Bd -literal -offset indent
8066 set termcap="colors=256"
8070 Keycodes can easily be detected with the command
8072 by running it on an interactive terminal via
8076 command line option if available) and pressing some keys: here
8084 (actually a visualized numeric where
8086 stands for 1 etc.; in fact: the numeric value of
8088 in the US-ASCII character set bitwise XORd with
8091 .Ql $ echo $((0x41 ^ 0x40)) .
8094 and other control characters have to be notated as shell-style
8095 escape sequences, e.g.,
8105 The following terminal capabilities are or may be meaningful for the
8106 operation of the builtin line editor or \*(UA in general:
8109 .Bl -tag -compact -width yay
8111 .It Cd colors Ns \0or Cd Co
8113 numeric capability specifying the maximum number of colours.
8114 Note that \*(UA doesn't actually care about the terminal beside that,
8115 but always emits ANSI/ISO 6429 escape sequences for producing the
8116 colour and font attributes.
8119 .It Cd rmcup Ns \0or Cd te Ns \0/ Cd smcup Ns \0or Cd ti
8123 respectively: exit and enter the alternative screen
8125 effectively turning \*(UA into a fullscreen application.
8126 To disable that, set (at least) one to the empty string.
8128 .It Cd smkx Ns \0or Cd ks Ns \0/ Cd rmkx Ns \0or Cd ke
8132 respectively: enable and disable the keypad.
8133 This is always enabled if available, because it seems even keyboards
8134 without keypads generate other key codes for, e.g., cursor keys in that
8135 case, and only if enabled we see the codes that we are interested in.
8137 .It Cd ed Ns \0or Cd cd
8141 .It Cd clear Ns \0or Cd cl
8143 clear the screen and home cursor.
8144 (Will be simulated via
8149 .It Cd home Ns \0or Cd ho
8154 .It Cd el Ns \0or Cd ce
8156 clear to the end of line.
8157 (Will be simulated via
8159 plus repititions of space characters.)
8161 .It Cd hpa Ns \0or Cd ch
8162 .Cd column_address :
8163 move the cursor (to the given column parameter) in the current row.
8164 (Will be simulated via
8170 .Cd carriage_return :
8171 move to the first column in the current row.
8172 The default builtin fallback is
8175 .It Cd cub1 Ns \0or Cd le
8177 move the cursor left one space (non-destructively).
8178 The default builtin fallback is
8181 .It Cd cuf1 Ns \0or Cd nd
8183 move the cursor right one space (non-destructively).
8184 The default builtin fallback is
8186 which is used by most terminals.
8195 .It Va termcap-disable
8196 \*(OP Disable any interaction with a terminal control library.
8197 If set only some generic fallback builtins and possibly the content of
8199 describe the terminal to \*(UA.
8201 that this variable will only be queried once at program startup and can
8202 thus only be specified in resource files or on the command line.
8206 If defined, gives the number of lines of a message to be displayed
8209 normally, the first five lines are printed.
8213 The character set of the terminal \*(UA operates on,
8214 and the one and only supported character set that \*(UA can use if no
8215 character set conversion capabilities have been compiled into it,
8216 in which case it defaults to ISO-8859-1 unless it can deduce a value
8220 Refer to the section
8221 .Sx "Character sets"
8222 for the complete picture about character sets.
8225 .It Va user-HOST , user
8226 \*(IN Variable chain that sets a global fallback user name, which is
8227 used in case none has been given in the protocol and account-specific
8229 This variable defaults to the name of the user who runs \*(UA.
8233 \*(BO Setting this option enables upward compatibility with \*(UA
8234 version 15.0 in respect to which configuration options are available and
8235 how they are handled.
8236 This manual uses \*(IN and \*(OU to refer to the new and the old way of
8237 doing things, respectively.
8241 \*(BO Setting this option, also controllable via the command line option
8243 causes \*(UA to be more verbose, e.g., it will display obsoletion
8244 warnings and SSL/TLS certificate chains.
8245 Even though marked \*(BO this option may be set twice in order to
8246 increase the level of verbosity even more, in which case even details of
8247 the actual message delivery and protocol conversations are shown.
8250 is sufficient to disable verbosity as such.
8256 .It Va version , version-major , version-minor , version-update
8257 \*(RO \*(UA version information: the first variable contains a string
8258 containing the complete version identification \(en this is identical to
8259 the output of the command
8261 The latter three contain only digits: the major, minor and update
8265 .It Va writebackedited
8266 If this variable is set messages modified using the
8270 commands are written back to the current folder when it is quit;
8271 it is only honoured for writable folders in MBOX format, though.
8272 Note that the editor will be pointed to the raw message content in that
8273 case, i.e., neither MIME decoding nor decryption will have been
8274 performed, and proper RFC 4155
8276 quoting of newly added or edited content is also left as an excercise to
8280 .\" }}} (INTERNAL VARIABLES)
8283 .\" .Sh ENVIRONMENT {{{
8287 .Dq environment variable
8288 should be considered an indication that these variables are either
8289 standardized as vivid parts of process environments, or that they are
8290 commonly found in there.
8291 The process environment is inherited from the
8293 once \*(UA is started, and unless otherwise explicitly noted handling of
8294 the following variables transparently integrates into that of the
8295 .Sx "INTERNAL VARIABLES"
8296 from \*(UA's point of view.
8297 This means that, e.g., they can be managed via
8301 causing automatic program environment updates (to be inherited by
8302 newly created child processes).
8305 In order to transparently integrate other environment variables equally
8306 they need to be imported (linked) with the command
8308 This command can also be used to set and unset non-integrated
8309 environment variables from scratch, sufficient system support provided.
8310 The following example, applicable to a POSIX shell, sets the
8312 environment variable for \*(UA only, and beforehand exports the
8314 in order to affect any further processing in the running shell:
8316 .Bd -literal -offset indent
8317 $ EDITOR="vim -u ${HOME}/.vimrc"
8319 $ COLUMNS=80 \*(uA -R
8322 .Bl -tag -width ".It Ev _AILR_"
8325 The user's preferred width in column positions for the terminal screen
8327 Queried and used once on program startup, actively managed for child
8328 processes and the MLE (see
8329 .Sx "On terminal control and line editor" )
8330 in interactive mode thereafter.
8334 The name of the file to use for saving aborted messages if
8336 is set; this defaults to
8344 Pathname of the text editor to use in the
8348 .Sx "TILDE ESCAPES" .
8349 A default editor is used if this value is not defined.
8353 The user's home directory.
8354 This variable is only used when it resides in the process environment.
8361 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
8365 .Sx "Character sets" .
8366 (Only recognized by the system in the process environment.)
8370 The user's preferred number of lines on a page or the vertical screen
8371 or window size in lines.
8372 Queried and used once on program startup, actively managed for child
8373 processes in interactive mode thereafter.
8377 Pathname of the directory lister to use in the
8379 command when operating on local mailboxes.
8382 (path search through
8387 Upon startup \*(UA will actively ensure that this variable refers to the
8388 name of the user who runs \*(UA, in order to be able to pass a verified
8389 name to any newly created child process.
8393 Is used as the user's primary system mailbox, if set.
8394 Otherwise, a system-dependent default is used.
8395 Supports the special syntax conventions that are documented for the
8401 \*(OP Overrides the default path search for
8402 .Sx "The Mailcap files" ,
8403 which is defined in the standard RFC 1524 as
8404 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
8405 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8406 (\*(UA makes it a configuration option, however.)
8407 Note this is not a search path, but a path search.
8411 Is used as a startup file instead of
8414 When \*(UA scripts are invoked on behalf of other users,
8415 either this variable should be set to
8419 command line option should be used in order to avoid side-effects from
8420 reading their configuration files.
8421 This variable is only used when it resides in the process environment.
8425 The name of the user's mbox file.
8426 A logical subset of the special conventions that are documented for the
8431 The fallback default is
8436 Traditionally this secondary mailbox is used as the file to save
8437 messages from the primary system mailbox that have been read.
8439 .Sx "Message states" .
8442 .It Ev NAIL_NO_SYSTEM_RC
8443 If this variable is set then reading of
8445 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8446 had been started up with the option
8448 This variable is only used when it resides in the process environment.
8452 \*(IN\*(OP This variable overrides the default location of the user's
8458 Pathname of the program to use for backing the command
8462 variable enforces usage of a pager for output.
8463 The default paginator is
8465 (path search through
8468 \*(UA inspects the contents of this variable: if its contains the string
8470 then a non-existing environment variable
8477 dependent on whether terminal control support is available and whether
8478 that supports full (alternative) screen mode or not (also see
8479 .Sx "On terminal control and line editor" ) .
8483 will optionally be set to
8490 A list of directories that is searched by the shell when looking for
8491 commands (as such only recognized in the process environment).
8495 The shell to use for the commands
8501 and when starting subprocesses.
8502 A default shell is used if this option is not defined.
8506 \*(OP The terminal type for which output is to be prepared.
8507 For extended colour and font control please refer to
8508 .Sx "Coloured display" ,
8509 and for terminal management in general to
8510 .Sx "On terminal control and line editor" .
8514 Used as directory for temporary files instead of
8517 This variable is only used when it resides in the process environment.
8523 (see there), but this variable is not standardized, should therefore not
8524 be used, and is only corrected if already set.
8528 Pathname of the text editor to use in the
8532 .Sx "TILDE ESCAPES" .
8540 .Bl -tag -width ".It Pa _etc/mime.type_"
8542 File giving initial commands.
8545 System wide initialization file.
8549 \*(OP Personal MIME type handler definition file, see
8550 .Sx "The Mailcap files" .
8551 (RFC 1524 location, the actual path is a configuration option.)
8555 \*(OP System wide MIME type handler definition file, see
8556 .Sx "The Mailcap files" .
8557 (RFC 1524 location, the actual path is a configuration option.)
8560 .It Pa ~/.mime.types
8561 Personal MIME types, see
8562 .Sx "The mime.types files" .
8565 .It Pa /etc/mime.types
8566 System wide MIME types, see
8567 .Sx "The mime.types files" .
8571 \*(IN\*(OP The default location of the users
8573 file \(en the section
8574 .Sx "The .netrc file"
8575 documents the file format.
8578 .\" .Ss "The mime.types files" {{{
8579 .Ss "The mime.types files"
8581 When sending messages \*(UA tries to determine the content type of all
8583 When displaying message content or attachments \*(UA uses the content
8584 type to decide wether it can directly display data or wether it needs to
8585 deal with content handlers.
8586 It learns about MIME types and how to treat them by reading
8588 files, the loading of which can be controlled by setting the variable
8589 .Va mimetypes-load-control .
8592 can also be used to deal with MIME types.)
8594 files have the following syntax:
8597 .Dl type/subtype extension [extension ...]
8602 are strings describing the file contents, and one or multiple
8604 s, separated by whitespace, name the part of a filename starting after
8605 the last dot (of interest).
8606 Comments may be introduced anywhere on a line with a number sign
8608 causing the remaining line to be discarded.
8610 \*(UA also supports an extended, non-portable syntax in specially
8611 crafted files, which can be loaded via the alternative value syntax of
8612 .Va mimetypes-load-control
8613 and prepends an optional
8617 .Dl [type-marker ]type/subtype extension [extension ...]
8620 The following type markers are supported:
8623 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8625 Treat message parts with this content as plain text.
8630 Treat message parts with this content as HTML tagsoup.
8631 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8632 the content as plain text instead.
8636 but instead of falling back to plain text require an explicit content
8637 handler to be defined.
8642 for sending messages:
8644 .Va mime-allow-text-controls ,
8645 .Va mimetypes-load-control .
8646 For reading etc. messages:
8647 .Sx "HTML mail and MIME attachments" ,
8648 .Sx "The Mailcap files" ,
8650 .Va mime-counter-evidence ,
8651 .Va mimetypes-load-control ,
8652 .Va pipe-TYPE/SUBTYPE ,
8653 .Va pipe-EXTENSION .
8656 .\" .Ss "The Mailcap files" {{{
8657 .Ss "The Mailcap files"
8660 .Dq User Agent Configuration Mechanism
8661 which \*(UA \*(OPally supports.
8662 It defines a file format to be used to inform mail user agent programs
8663 about the locally-installed facilities for handling various data
8664 formats, i.e., about commands and how they can be used to display, edit
8665 etc. MIME part contents, as well as a default path search that includes
8666 multiple possible locations of
8670 environment variable that can be used to overwrite that (repeating here
8671 that it is not a search path, but instead a path search specification).
8672 Any existing files will be loaded in sequence, appending any content to
8673 the list of MIME type handler directives.
8677 files consist of a set of newline separated entries.
8678 Comment lines start with a number sign
8680 (in the first column!) and are ignored.
8681 Empty lines are also ignored.
8682 All other lines form individual entries that must adhere to the syntax
8684 To extend a single entry (not comment) its line can be continued on
8685 follow lines if newline characters are
8687 by preceding them with the backslash character
8689 The standard doesn't specify how leading whitespace of follow lines is
8690 to be treated, therefore \*(UA retains it.
8694 entries consist of a number of semicolon
8696 separated fields, and the backslash
8698 character can be used to escape any following character including
8699 semicolon and itself.
8700 The first two fields are mandatory and must occur in the specified
8701 order, the remaining fields are optional and may appear in any order.
8702 Leading and trailing whitespace of content is ignored (removed).
8705 The first field defines the MIME
8707 the entry is about to handle (case-insensitively, and no backslash
8708 escaping is possible in this field).
8709 If the subtype is specified as an asterisk
8711 the entry is ment to match all subtypes of the named type, e.g.,
8713 would match any audio type.
8714 The second field defines the shell command which shall be used to
8716 MIME parts of the given type; it is implicitly called the
8723 shell commands message (MIME part) data is passed via standard input
8724 unless the given shell command includes one or more instances of the
8727 in which case these instances will be replaced with a temporary filename
8728 and the data will have been stored in the file that is being pointed to.
8731 shell commands data is assumed to be generated on standard output unless
8732 the given command includes (one ore multiple)
8734 In any case any given
8736 format is replaced with a(n already) properly quoted filename.
8737 Note that when a command makes use of a temporary file via
8739 then \*(UA will remove it again, as if the
8740 .Cd x-mailx-tmpfile ,
8741 .Cd x-mailx-tmpfile-fill
8743 .Cd x-mailx-tmpfile-unlink
8744 flags had been set; see below for more.
8747 The optional fields either define a shell command or an attribute (flag)
8748 value, the latter being a single word and the former being a keyword
8749 naming the field followed by an equals sign
8751 succeeded by a shell command, and as usual for any
8753 content any whitespace surrounding the equals sign will be removed, too.
8754 Optional fields include the following:
8757 .Bl -tag -width textualnewlines
8759 A program that can be used to compose a new body or body part in the
8766 field, but is to be used when the composing program needs to specify the
8768 header field to be applied to the composed data.
8772 A program that can be used to edit a body or body part in the given
8777 A program that can be used to print a message or body part in the given
8782 Specifies a program to be run to test some condition, e.g., the machine
8783 architecture, or the window system in use, to determine whether or not
8784 this mailcap entry applies.
8785 If the test fails, a subsequent mailcap entry should be sought; also see
8786 .Cd x-mailx-test-once .
8788 .It Cd needsterminal
8789 This flag field indicates that the given shell command must be run on
8790 an interactive terminal.
8791 \*(UA will temporarily release the terminal to the given command in
8792 interactive mode, in non-interactive mode this entry will be entirely
8793 ignored; this flag implies
8794 .Cd x-mailx-noquote .
8796 .It Cd copiousoutput
8797 A flag field which indicates that the output of the
8799 command will be an extended stream of textual output that can be
8800 (re)integrated into \*(UA's normal visual display.
8801 It is mutually exclusive with
8804 .Cd x-mailx-always .
8806 .It Cd textualnewlines
8807 A flag field which indicates that this type of data is line-oriented and
8810 all newlines should be converted to canonical form (CRLF) before
8811 encoding, and will be in that form after decoding.
8815 This field gives a file name format, in which
8817 will be replaced by a random string, the joined combination of which
8818 will be used as the filename denoted by
8819 .Ev NAIL_FILENAME_TEMPORARY .
8820 One could specify that a GIF file being passed to an image viewer should
8821 have a name ending in
8824 .Ql nametemplate=%s.gif .
8825 Note that \*(UA ignores the name template unless that solely specifies
8826 a filename suffix that consists of (ASCII) alphabetic and numeric
8827 characters, the underscore and dot only.
8830 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8831 icon to be used to visually denote the presence of this kind of data.
8832 This field is not used by \*(UA.
8835 A textual description that describes this type of data.
8837 .It Cd x-mailx-always
8838 Extension flag field that denotes that the given
8840 command shall be executed even if multiple messages will be displayed
8842 Normally messages which require external viewers that produce output
8843 which doesn't integrate into \*(UA's visual display (i.e., don't have
8845 set) have to be addressed directly and individually.
8846 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8849 .It Cd x-mailx-even-if-not-interactive
8850 An extension flag test field \(em by default handlers without
8852 are entirely ignored in non-interactive mode, but if this flag is set
8853 then their use will be considered.
8854 It is an error if this flag is set for commands that use the flag
8857 .It Cd x-mailx-noquote
8858 An extension flag field that indicates that even a
8861 command shall not be used to generate message quotes
8862 (as it would be by default).
8864 .It Cd x-mailx-async
8865 Extension flag field that denotes that the given
8867 command shall be executed asynchronously, without blocking \*(UA.
8868 Cannot be used in conjunction with
8871 .It Cd x-mailx-test-once
8872 Extension flag which denotes wether the given
8874 command shall be evaluated once only and the (boolean) result be cached.
8875 This is handy if some global unchanging condition is to be queried, like
8876 .Dq running under the X Window System .
8878 .It Cd x-mailx-tmpfile
8879 Extension flag field that requests creation of a zero-sized temporary
8880 file, the name of which is to be placed in the environment variable
8881 .Ev NAIL_FILENAME_TEMPORARY .
8882 It is an error to use this flag with commands that include a
8886 .It Cd x-mailx-tmpfile-fill
8887 Normally the MIME part content is passed to the handler via standard
8888 input; if this flag is set then the data will instead be written into
8890 .Cd x-mailx-tmpfile .
8891 In order to cause deletion of the temporary file you will have to set
8892 .Cd x-mailx-tmpfile-unlink
8894 It is an error to use this flag with commands that include a
8898 .It Cd x-mailx-tmpfile-unlink
8899 Extension flag field that requests that the temporary file shall be
8900 deleted automatically when the command loop is entered again at latest.
8901 (Don't use this for asynchronous handlers.)
8902 It is an error to use this flag with commands that include a
8904 format, or without also setting
8907 .Cd x-mailx-tmpfile-fill .
8909 .It Cd x-mailx-tmpfile-keep
8912 implies the three tmpfile related flags above, but if you want, e.g.,
8914 and deal with the temporary file yourself, you can add in this flag to
8916 .Cd x-mailx-tmpfile-unlink .
8921 The standard includes the possibility to define any number of additional
8922 entry fields, prefixed by
8924 Flag fields apply to the entire
8926 entry \(em in some unusual cases, this may not be desirable, but
8927 differentiation can be accomplished via separate entries, taking
8928 advantage of the fact that subsequent entries are searched if an earlier
8929 one does not provide enough information.
8932 command needs to specify the
8936 command shall not, the following will help out the latter (with enabled
8940 level \*(UA will show informations about handler evaluation):
8942 .Bd -literal -offset indent
8943 application/postscript; ps-to-terminal %s; needsterminal
8944 application/postscript; ps-to-terminal %s; compose=idraw %s
8948 In fields any occurrence of the format string
8950 will be replaced by the
8953 Named parameters from the
8955 field may be placed in the command execution line using
8957 followed by the parameter name and a closing
8960 The entire parameter should appear as a single command line argument,
8961 regardless of embedded spaces; thus:
8963 .Bd -literal -offset indent
8965 Content-type: multipart/mixed; boundary=42
8968 multipart/*; /usr/local/bin/showmulti \e
8969 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8971 # Executed shell command
8972 /usr/local/bin/showmulti multipart/mixed 42
8976 .\" TODO v15: Mailcap: %n,%F
8977 Note that \*(UA doesn't support handlers for multipart MIME parts as
8978 shown in this example (as of today).
8979 \*(UA doesn't support the additional formats
8983 An example file, also showing how to properly deal with the expansion of
8985 which includes any quotes that are necessary to make it a valid shell
8986 argument by itself and thus will cause undesired behaviour when placed
8987 in additional user-provided quotes:
8989 .Bd -literal -offset indent
8991 text/richtext; richtext %s; copiousoutput
8993 text/x-perl; perl -cWT %s
8997 trap "rm -f ${infile}" EXIT\e; \e
8998 trap "exit 75" INT QUIT TERM\e; \e
9000 x-mailx-async; x-mailx-tmpfile-keep
9002 application/*; echo "This is \e"%t\e" but \e
9003 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
9004 copiousoutput; x-mailx-noquote
9009 .Sx "HTML mail and MIME attachments" ,
9010 .Sx "The mime.types files" ,
9013 .Va mime-counter-evidence ,
9014 .Va pipe-TYPE/SUBTYPE ,
9015 .Va pipe-EXTENSION .
9018 .\" .Ss "The .netrc file" {{{
9019 .Ss "The .netrc file"
9023 file contains user credentials for machine accounts.
9024 The default location in the user's
9026 directory may be overridden by the
9028 environment variable.
9029 The file consists of space, tabulator or newline separated tokens.
9030 \*(UA implements a parser that supports a superset of the original BSD
9031 syntax, but users should nonetheless be aware of portability glitches
9032 of that file format, shall their
9034 be usable across multiple programs and platforms:
9037 .Bl -bullet -compact
9039 BSD doesn't support single, but only double quotation marks, e.g.,
9040 .Ql password="pass with spaces" .
9042 BSD (only?) supports escaping of single characters via a backslash
9043 (e.g., a space can be escaped via
9045 in- as well as outside of a quoted string.
9047 BSD doesn't require the final quotation mark of the final user input token.
9049 The original BSD (Berknet) parser also supported a format which allowed
9050 tokens to be separated with commas \(en whereas at least Hewlett-Packard
9051 still seems to support this syntax, \*(UA does not!
9053 As a non-portable extension some widely-used programs support
9054 shell-style comments: if an input line starts, after any amount of
9055 whitespace, with a number sign
9057 then the rest of the line is ignored.
9059 Whereas other programs may require that the
9061 file is accessible by only the user if it contains a
9067 \*(UA will always require these strict permissions.
9071 Of the following list of supported tokens \*(UA only uses (and caches)
9076 At runtime the command
9078 can be used to control \*(UA's
9082 .Bl -tag -width password
9083 .It Cd machine Ar name
9084 The hostname of the entries' machine, lowercase-normalized by \*(UA
9086 Any further file content, until either end-of-file or the occurrence
9091 first-class token is bound (only related) to the machine
9094 As an extension that shouldn't be the cause of any worries
9095 \*(UA supports a single wildcard prefix for
9097 .Bd -literal -offset indent
9098 machine *.example.com login USER password PASS
9099 machine pop3.example.com login USER password PASS
9100 machine smtp.example.com login USER password PASS
9106 .Ql pop3.example.com ,
9110 .Ql local.smtp.example.com .
9111 Note that in the example neither
9112 .Ql pop3.example.com
9114 .Ql smtp.example.com
9115 will be matched by the wildcard, since the exact matches take
9116 precedence (it is however faster to specify it the other way around).
9121 except that it is a fallback entry that is used shall none of the
9122 specified machines match; only one default token may be specified,
9123 and it must be the last first-class token.
9125 .It Cd login Ar name
9126 The user name on the remote machine.
9128 .It Cd password Ar string
9129 The user's password on the remote machine.
9131 .It Cd account Ar string
9132 Supply an additional account password.
9133 This is merely for FTP purposes.
9135 .It Cd macdef Ar name
9137 A macro is defined with the specified
9139 it is formed from all lines beginning with the next line and continuing
9140 until a blank line is (consecutive newline characters are) encountered.
9143 entries cannot be utilized by multiple machines, too, but must be
9144 defined following the
9146 they are intended to be used with.)
9149 exists, it is automatically run as the last step of the login process.
9150 This is merely for FTP purposes.
9157 .\" .Sh EXAMPLES {{{
9160 .\" .Ss "An example configuration" {{{
9161 .Ss "An example configuration"
9163 .Bd -literal -offset indent
9164 # This example assumes v15.0 compatibility mode
9167 # Where are the up-to-date SSL certificates?
9168 #set ssl-ca-dir=/etc/ssl/certs
9169 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
9171 # (Since we manage up-to-date ones explicitly, don't use any,
9172 # possibly outdated, default certificates shipped with OpenSSL
9173 set ssl-no-default-ca
9175 # Don't use protocols older than TLS v1.2.
9176 # Change this only when the remote server doesn't support it:
9177 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
9178 # such explicit exceptions, then
9179 set ssl-protocol='-ALL,+TLSv1.2'
9181 # Explicitly define the list of ciphers, which may improve security,
9182 # especially with protocols older than TLS v1.2. See ciphers(1).
9183 # Hint: it is important to include "@STRENGTH": only with it the
9184 # final list will be sorted by algorithm strength.
9185 # This is an example: in reality it is possibly best to only use
9186 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
9187 set ssl-cipher-list='ALL:!aNULL:!MEDIUM:!LOW:\e
9188 !MD5:!RC4:!EXPORT:@STRENGTH'
9190 # Request strict transport security checks!
9191 set ssl-verify=strict
9193 # Essential setting: select allowed character sets
9194 set sendcharsets=utf-8,iso-8859-1
9196 # A very kind option: when replying to a message, first try to
9197 # use the same encoding that the original poster used herself!
9198 set reply-in-same-charset
9200 # When replying to or forwarding a message the comment and name
9201 # parts of email addresses are removed unless this variable is set
9204 # When sending messages, wait until the Mail-Transfer-Agent finishs.
9205 # Only like this you'll be able to see errors reported through the
9206 # exit status of the MTA (including the builtin SMTP one)!
9209 # Only use builtin MIME types, no mime.types(5) files
9210 set mimetypes-load-control
9212 # Default directory where we act in (relative to $HOME)
9214 # A leading "+" (often) means: under *folder*
9215 # *record* is used to save copies of sent messages
9216 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
9218 # Make "file mymbox" and "file myrec" go to..
9219 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
9221 # Not really optional, e.g., for S/MIME
9222 set from='Your Name <address@exam.ple>'
9224 # It may be necessary to set hostname and/or smtp-hostname
9225 # if the "SERVER" of smtp and "domain" of from don't match.
9226 # The `urlencode' command can be used to encode USER and PASS
9227 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
9228 smtp-auth=login/plain... \e
9231 # Never refuse to start into interactive mode, and more
9233 colour-pager crt= \e
9234 followup-to followup-to-honour=ask-yes \e
9235 history-file=+.\*(uAhist history-size=-1 history-gabby \e
9236 mime-counter-evidence=0xE \e
9237 prompt='?\e?[\e$ \e@]\e& ' \e
9238 reply-to-honour=ask-yes
9240 # When `t'yping messages, show only these headers
9241 # (use `T'ype for all headers and `S'how for raw message)
9242 retain date from to cc subject
9244 # Some mailing lists
9245 mlist '@xyz-editor\e.xyz'$ '@xyzf\e.xyz$'
9246 mlsubscribe '^xfans@xfans\e.xyz$'
9248 # A real life example of a very huge free mail provider
9250 set folder=~/spool/XooglX MAIL=+syste.mbox sent=+sent
9251 set from='Your Name <address@examp.ple>'
9252 # (The plain smtp:// proto is optional)
9253 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
9256 # Here is a pretty large one which does not allow sending mails
9257 # if there is a domain name mismatch on the SMTP protocol level,
9258 # which would bite us if the value of from does not match, e.g.,
9259 # for people who have a sXXXXeforge project and want to speak
9260 # with the mailing list under their project account (in from),
9261 # still sending the message through their normal mail provider
9263 set folder=~/spool/XandeX MAIL=+syste.mbox sent=+sent
9264 set from='Your Name <address@exam.ple>'
9265 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
9266 hostname=yaXXex.com smtp-hostname=
9269 # Create some new commands so that, e.g., `ls /tmp' will..
9280 ghost llS !ls -aFlrS
9283 # We don't support gpg(1) directly yet. But simple --clearsign'd
9284 # message parts can be dealt with as follows:
9286 wysh set pipe-text/plain=$'@*#++=@\e
9287 < "${NAIL_FILENAME_TEMPORARY}" awk \e
9288 -v TMPFILE="${NAIL_FILENAME_TEMPORARY}" \e'\e
9290 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/{\e
9293 print "--- GPG --verify ---";\e
9294 system("gpg --verify " TMPFILE " 2>&1");\e
9295 print "--- GPG --verify ---";\e
9299 /^-----BEGIN PGP SIGNATURE-----/,\e
9300 /^-----END PGP SIGNATURE-----/{\e
9310 !printf 'Key IDs to gpg --recv-keys: ';\e
9312 gpg --recv-keys ${keyids};
9318 When storing passwords in
9320 appropriate permissions should be set on this file with
9321 .Ql $ chmod 0600 \*(ur .
9324 is available user credentials can be stored in the central
9326 file instead; e.g., here is a different version of the example account
9327 that sets up SMTP and POP3:
9329 .Bd -literal -offset indent
9331 set folder=~/spool/XandeX MAIL=+syste.mbox sent=+sent
9332 set from='Your Name <address@exam.ple>'
9334 #set agent-shell-lookup='gpg -d .pass.gpg'
9336 set smtp=smtps://smtp.yXXXXx.ru:465 \e
9337 smtp-hostname= hostname=yXXXXx.com
9338 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
9339 ghost xp fi pop3s://pop.yXXXXx.ru
9348 .Bd -literal -offset indent
9349 machine *.yXXXXx.ru login USER password PASS
9354 .Va agent-shell-lookup
9355 is available things could be diversified further by using encrypted
9356 password storage: for this, don't specify
9360 file and instead uncomment the line that defines agent lookup in the
9363 above, then create the encrypted password storage file
9366 .Bd -literal -offset indent
9369 $ eval `gpg-agent --daemon \e
9370 --pinentry-program=/usr/bin/pinentry-curses \e
9371 --max-cache-ttl 99999 --default-cache-ttl 99999`
9375 This configuration should now work just fine (use the
9377 command line option for a(n almost) dry-run):
9380 .Dl $ echo text | \*(uA -vv -AXandeX -s Subject user@exam.ple
9383 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
9384 .Ss "Signed and encrypted messages with S/MIME"
9386 \*(OP S/MIME provides two central mechanisms:
9387 message signing and message encryption.
9388 A signed message contains some data in addition to the regular text.
9389 The data can be used to verify that the message was sent using a valid
9390 certificate, that the sender's address in the message header matches
9391 that in the certificate, and that the message text has not been altered.
9392 Signing a message does not change its regular text;
9393 it can be read regardless of whether the recipient's software is able to
9397 It is thus usually possible to sign all outgoing messages if so desired.
9398 Encryption, in contrast, makes the message text invisible for all people
9399 except those who have access to the secret decryption key.
9400 To encrypt a message, the specific recipient's public encryption key
9402 It is therefore not possible to send encrypted mail to people unless their
9403 key has been retrieved from either previous communication or public key
9405 A message should always be signed before it is encrypted.
9406 Otherwise, it is still possible that the encrypted message text is
9410 A central concept to S/MIME is that of the certification authority (CA).
9411 A CA is a trusted institution that issues certificates.
9412 For each of these certificates it can be verified that it really
9413 originates from the CA, provided that the CA's own certificate is
9415 A set of CA certificates is usually delivered with OpenSSL and installed
9417 If you trust the source of your OpenSSL software installation,
9418 this offers reasonable security for S/MIME on the Internet.
9420 .Va ssl-no-default-ca
9424 .Va smime-ca-dir . )
9425 In general, a certificate cannot be more secure than the method its CA
9426 certificate has been retrieved with, though.
9427 Thus if you download a CA certificate from the Internet,
9428 you can only trust the messages you verify using that certificate as
9429 much as you trust the download process.
9432 The first thing you need for participating in S/MIME message exchange is
9433 your personal certificate, including a private key.
9434 The certificate contains public information, in particular your name and
9435 your email address(es), and the public key that is used by others to
9436 encrypt messages for you,
9437 and to verify signed messages they supposedly received from you.
9438 The certificate is included in each signed message you send.
9439 The private key must be kept secret.
9440 It is used to decrypt messages that were previously encrypted with your
9441 public key, and to sign messages.
9444 For personal use it is recommended that you get a S/MIME certificate
9445 from one of the major CAs on the Internet using your WWW browser.
9446 Many CAs offer such certificates for free.
9448 .Lk https://www.CAcert.org
9449 which issues client and server certificates to members of their
9450 community for free; their root certificate
9451 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9452 is often not in the default set of trusted CA root certificates, though,
9453 which means you will have to download their root certificate separately
9454 and ensure it is part of our S/MIME certificate validation chain by
9457 or as a vivid member of the
9459 But let's take a step-by-step tour on how to setup S/MIME with
9460 a certificate from CAcert.org despite this situation!
9463 First of all you will have to become a member of the CAcert.org
9464 community, simply by registrating yourself via the web interface.
9465 Once you are, create and verify all email addresses you want to be able
9466 to create signed and encrypted messages for/with using the corresponding
9467 entries of the web interface.
9468 Now ready to create S/MIME certificates, so let's create a new
9469 .Dq client certificate ,
9470 ensure to include all email addresses that should be covered by the
9471 certificate in the following web form, and also to use your name as the
9475 Create a private key and a certificate request on your local computer
9476 (please see the manual pages of the used commands for more in-depth
9477 knowledge on what the used arguments etc. do):
9480 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9483 Afterwards copy-and-paste the content of
9485 into the certificate-request (CSR) field of the web form on the
9486 CAcert.org website (you may need to unfold some
9487 .Dq advanced options
9488 to see the corresponding text field).
9489 This last step will ensure that your private key (which never left your
9490 box) and the certificate belong together (through the public key that
9491 will find its way into the certificate via the certificate-request).
9492 You are now ready and can create your CAcert certified certificate.
9493 Download and store or copy-and-paste it as
9498 In order to use your new S/MIME setup you will have to create
9499 a combined private key/public key (certificate) file:
9502 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9505 This is the file \*(UA will work with.
9506 If you have created your private key with a passphrase then \*(UA will
9507 ask you for it whenever a message is signed or decrypted.
9508 Set the following variables to henceforth use S/MIME (setting
9510 is of interest for verification only):
9512 .Bd -literal -offset indent
9513 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9514 smime-sign-cert=ME@HERE.com.paired \e
9515 smime-sign-message-digest=SHA256 \e
9520 From each signed message you send, the recipient can fetch your
9521 certificate and use it to send encrypted mail back to you.
9522 Accordingly if somebody sends you a signed message, you can do the same,
9525 command to check the validity of the certificate.
9528 Variables of interest for S/MIME signing:
9532 .Va smime-crl-file ,
9533 .Va smime-no-default-ca ,
9535 .Va smime-sign-cert ,
9536 .Va smime-sign-include-certs
9538 .Va smime-sign-message-digest .
9541 After it has been verified save the certificate via
9543 and tell \*(UA that it should use it for encryption for further
9544 communication with that somebody:
9546 .Bd -literal -offset indent
9548 set smime-encrypt-USER@HOST=FILENAME \e
9549 smime-cipher-USER@HOST=AES256
9553 Additional variables of interest for S/MIME en- and decryption:
9556 .Va smime-encrypt-USER@HOST .
9559 You should carefully consider if you prefer to store encrypted messages
9561 If you do, anybody who has access to your mail folders can read them,
9562 but if you do not, you might be unable to read them yourself later if
9563 you happen to lose your private key.
9566 command saves messages in decrypted form, while the
9570 commands leave them encrypted.
9573 Note that neither S/MIME signing nor encryption applies to message
9574 subjects or other header fields yet.
9575 Thus they may not contain sensitive information for encrypted messages,
9576 and cannot be trusted even if the message content has been verified.
9577 When sending signed messages,
9578 it is recommended to repeat any important header information in the
9582 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9583 .Ss "Using CRLs with S/MIME or SSL/TLS"
9585 \*(OP Certification authorities (CAs) issue certificate revocation
9586 lists (CRLs) on a regular basis.
9587 These lists contain the serial numbers of certificates that have been
9588 declared invalid after they have been issued.
9589 Such usually happens because the private key for the certificate has
9591 because the owner of the certificate has left the organization that is
9592 mentioned in the certificate, etc.
9593 To seriously use S/MIME or SSL/TLS verification,
9594 an up-to-date CRL is required for each trusted CA.
9595 There is otherwise no method to distinguish between valid and
9596 invalidated certificates.
9597 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9598 the Internet, so you have to retrieve them by some external mechanism.
9601 \*(UA accepts CRLs in PEM format only;
9602 CRLs in DER format must be converted, like, e.\|g.:
9605 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9608 To tell \*(UA about the CRLs, a directory that contains all CRL files
9609 (and no other files) must be created.
9614 variables, respectively, must then be set to point to that directory.
9615 After that, \*(UA requires a CRL to be present for each CA that is used
9616 to verify a certificate.
9619 .\" .Ss "Handling spam" {{{
9622 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9623 identification of, and, in general, dealing with spam messages.
9624 A precondition of most commands in order to function is that the
9626 variable is set to one of the supported interfaces.
9627 Once messages have been identified as spam their (volatile)
9629 state can be prompted: the
9633 message specifications will address respective messages and their
9635 entries will be used when displaying the
9637 in the header display.
9642 rates the given messages and sets their
9645 If the spam interface offers spam scores those can also be displayed in
9646 the header display by including the
9656 will interact with the Bayesian filter of the chosen interface and learn
9657 the given messages as
9661 respectively; the last command can be used to cause
9663 of messages; it adheres to their current
9665 state and thus reverts previous teachings.
9670 will simply set and clear, respectively, the mentioned volatile
9672 message flag, without any interface interaction.
9679 .Va spam-interface Ns s
9683 require a running instance of the
9685 server in order to function, started with the option
9687 shall Bayesian filter learning be possible.
9689 only works via a local path-based
9691 socket, but otherwise the following will be equivalently fine:
9693 .Bd -literal -offset indent
9694 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9695 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9696 --daemonize [--local] [--allow-tell]
9700 Thereafter \*(UA can make use of these interfaces:
9702 .Bd -literal -offset indent
9703 $ \*(uA -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9704 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9706 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9707 -Sspamc-command=/usr/local/bin/spamc \e
9708 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9710 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9711 -Sspamc-command=/usr/local/bin/spamc \e
9712 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9716 Using the generic filter approach allows usage of programs like
9720 Here is an example for the former, requiring it to be accessible via
9723 .Bd -literal -offset indent
9724 $ \*(uA -Sspam-interface=filter -Sspam-maxsize=500000 \e
9725 -Sspamfilter-ham="bogofilter -n" \e
9726 -Sspamfilter-noham="bogofilter -N" \e
9727 -Sspamfilter-nospam="bogofilter -S" \e
9728 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9729 -Sspamfilter-spam="bogofilter -s" \e
9730 -Sspamfilter-rate-scanscore="1;^(.+)$"
9734 Because messages must exist on local storage in order to be scored (or
9735 used for Bayesian filter training), it is possibly a good idea to
9736 perform the local spam check last:
9738 .Bd -literal -offset indent
9739 define spamdelhook {
9741 spamset (header x-dcc-brand-metrics "bulk")
9742 # Server-side spamassassin(1)
9743 spamset (header x-spam-flag "YES")
9744 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9750 set folder-hook-FOLDER=spamdelhook
9754 See also the documentation for the variables
9755 .Va spam-interface , spam-maxsize ,
9756 .Va spamc-command , spamc-arguments , spamc-user ,
9757 .Va spamd-socket , spamd-user ,
9758 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9761 .Va spamfilter-rate-scanscore .
9769 .\" .Ss "\*(UA shortly hangs on startup" {{{
9770 .Ss "\*(UA shortly hangs on startup"
9772 This can have two reasons, one is the necessity to wait for a file lock
9773 and can't be helped, the other being that \*(UA calls the function
9775 in order to query the nodename of the box (sometimes the real one is
9776 needed instead of the one represented by the internal variable
9778 You may have varying success by ensuring that the real hostname and
9782 or, more generally, that the name service is properly setup \(en
9785 return what you'd expect?
9786 Does this local hostname has a domain suffix?
9787 RFC 6762 standardized the link-local top-level domain
9791 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9792 .Ss "I can't login to Google mail a.k.a. GMail"
9794 Since 2014 some free service providers classify programs as
9796 unless they use a special authentification method (OAuth 2.0) which
9797 wasn't standardized for non-HTTP protocol authentication token query
9798 until August 2015 (RFC 7628).
9801 Different to Kerberos / GSSAPI, which is developed since the mid of the
9802 1980s, where a user can easily create a local authentication ticket for
9803 her- and himself with the locally installed
9805 program, that protocol has no such local part but instead requires
9806 a world-wide-web query to create or fetch a token; since there is no
9807 local cache this query has to be performed whenever \*(UA is invoked
9808 from the command line (in interactive sessions situation may differ).
9811 \*(UA doesn't support OAuth.
9812 Because of this it is necessary to declare \*(UA a
9814 (on the providers account web page) in order to read and send mail.
9815 However, it also seems possible to take the following steps instead:
9820 give the provider the number of a mobile phone,
9823 .Dq 2-Step Verification ,
9825 create an application specific password (16 characters), and
9827 use that special password instead of your real Google account password in
9828 S-nail (for more on that see the section
9829 .Sx "On URL syntax and credential lookup" ) .
9835 .\" .Sh "SEE ALSO" {{{
9853 .Xr spamassassin 1 ,
9879 M. Douglas McIlroy writes in his article
9880 .Dq A Research UNIX Reader: Annotated Excerpts \
9881 from the Programmer's Manual, 1971-1986
9884 command already appeared in First Edition
9888 .Bd -ragged -offset indent
9889 Electronic mail was there from the start.
9890 Never satisfied with its exact behavior, everybody touched it at one
9891 time or another: to assure the safety of simultaneous access, to improve
9892 privacy, to survive crashes, to exploit uucp, to screen out foreign
9893 freeloaders, or whatever.
9894 Not until v7 did the interface change (Thompson).
9895 Later, as mail became global in its reach, Dave Presotto took charge and
9896 brought order to communications with a grab-bag of external networks
9902 Mail was written in 1978 by Kurt Shoens and developed as part of the
9905 distribution until 1995.
9906 Mail has then seen further development in open source
9908 variants, noticeably by Christos Zoulas in
9910 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9911 Ritter in the years 2000 until 2008.
9912 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9913 This man page is derived from
9914 .Dq The Mail Reference Manual
9915 that was originally written by Kurt Shoens.
9922 .An "Christos Zoulas" ,
9923 .An "Gunnar Ritter" ,
9924 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9926 .Mt s-mailx@sdaoden.eu ) .
9932 The character set conversion uses and relies upon the
9935 Its functionality differs widely between the various system environments
9939 Limitations with POP3 mailboxes are:
9940 It is not possible to edit messages, they can only be copied and deleted.
9941 The line count for the header display is only appropriate if the entire
9942 message has been downloaded from the server.
9943 The status field of a message is maintained by the server between
9944 connections; some servers do not update it at all, and with a server
9947 command will not cause the message status to be reset.
9952 variable have no effect.
9953 It is not possible to rename or to remove POP3 mailboxes.
9960 is typed while a POP3 operation is in progress, \*(UA will wait
9961 until the operation can be safely aborted, and will then return to the
9962 command loop and print the prompt again.
9965 is typed while \*(UA is waiting for the operation to complete, the
9966 operation itself will be cancelled.
9967 In this case, data that has not been fetched yet will have to be fetched
9968 before the next command can be performed.
9969 If the cancelled operation was using an SSL/TLS encrypted channel,
9970 an error in the SSL transport will very likely result and render the
9971 connection unusable.
9974 As \*(UA is a mail user agent, it provides only basic SMTP services.
9975 If it fails to contact its upstream SMTP server, it will not make
9976 further attempts to transfer the message at a later time,
9977 and it does not leave other information about this condition than an
9978 error message on the terminal and an entry in
9980 This is usually not a problem if the SMTP server is located in the same
9981 local network as the computer on which \*(UA is run.
9982 However, care should be taken when using a remote server of an ISP;
9983 it might be better to set up a local SMTP server then which just acts as
9987 \*(UA immediately contacts the SMTP server (or
9989 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9990 servers usually provide much more elaborated delay handling than \*(UA
9991 could perform as a client.
9999 from the distribution or the repository.
10001 After deleting some message of a POP3 mailbox the header summary falsely
10002 claims that there are no messages to display, you need to perform
10003 a scroll or dot movement to restore proper state.
10005 In threaded display a power user may encounter crashes very
10006 occasionally (this is may and very).