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
27 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 On new-style command lines it is wise to quote semicolon
2589 characters in order to ensure upward compatibility: the author would
2590 like to see things like
2591 .Ql ? echo $'trouble\tahead' | cat >> in_the_shell.txt
2593 .Ql ? top 2 5 10; type 3 22
2595 Before \*(UA will switch entirely to shell-style argument parsing there
2596 will be a transition phase where using
2598 will emit obsoletion warnings.
2599 E.g., the following are equivalent:
2601 .Bd -literal -offset indent
2602 mlist @any\e\e.where\e\e.example\e\e.com
2603 wysh mlist '@any\e.where\e.example\e.com' # This is a comment
2604 wysh mlist $'@any\e\e\ex2Ewhere\e\e.example\e\e\e56com' # A comment
2605 wysh mlist "@any\e.where\e.example\e.com"
2609 In any event an unquoted backslash at the end of a command line is
2610 discarded and the next line continues the command.
2611 \*(ID Note that line continuation is handled before the above parsing is
2612 applied, i.e., the parsers documented above will see merged lines.
2613 Filenames, where expected, are subsequently subjected to the following
2614 transformations, in sequence:
2617 .Bl -bullet -compact -offset indent
2619 If the filename begins with an unquoted plus sign, and the
2621 variable is defined,
2622 the plus sign will be replaced by the value of the
2624 variable followed by a slash.
2627 variable is unset or is set to null, the filename will be unchanged.
2630 Meta expansions are applied to the filename: a leading tilde
2632 character will be replaced by the expansion of
2634 except when followed by a valid user name, in which case the home
2635 directory of the given user is used instead.
2640 will be replaced by the expansion of the variable, if possible; \*(UA
2641 .Sx "INTERNAL VARIABLES"
2644 (shell) variables can be accessed through this mechanism, and the usual
2645 escape mechanism has to be applied to prevent interpretation.
2646 If the fully expanded filename results in multiple pathnames and the
2647 command is expecting only one file, an error results.
2649 In interactive context, in order to allow simple value acceptance (via
2651 arguments will usually be displayed in a properly quoted form, e.g., a file
2652 .Ql diet\e is \ecurd.txt
2654 .Ql 'diet\e is \ecurd.txt' .
2658 The following commands are available:
2660 .Bl -tag -width ".Ic _ccount"
2667 ) command which follows.
2671 The comment-command causes the entire line to be ignored.
2673 this really is a normal command which' purpose is to discard its
2676 indicating special character, which means that, e.g., trailing comments
2677 on a line are not possible.
2681 Goes to the next message in sequence and types it
2687 Display the preceding message, or the n'th previous message if given
2688 a numeric argument n.
2692 Show the current message number (the
2697 Show a brief summary of commands.
2698 \*(OP Given an argument a synopsis for the command in question is
2699 shown instead; commands can be abbreviated in general and this command
2700 can be used to see the full expansion of an abbreviation including the
2701 synopsis, try, e.g.,
2706 and see how the output changes.
2716 Interprets the remainder of the word as a macro name and passes it
2721 is a shorter synonym for
2722 .Ql call Ar mymacro .
2726 (ac) Creates, selects or lists (an) account(s).
2727 Accounts are special incarnations of
2729 macros and group commands and variable settings which together usually
2730 arrange the environment for the purpose of creating an email account.
2731 Different to normal macros settings which are covered by
2733 \(en here by default enabled! \(en will not be reverted before the
2738 (case-insensitive) always exists, and all but it can be deleted via
2741 Without arguments a listing of all defined accounts is shown.
2742 With one argument the given account is activated: the system
2744 box of that account will be activated (as via
2746 and a possibly installed
2749 The two argument form is identical to defining a macro as via
2751 .Bd -literal -offset indent
2753 set folder=~/mail MAIL=+syste.mbox record=+sent.mbox
2754 set from='myname@myisp.example (My Name)'
2755 set smtp=smtp://mylogin@smtp.myisp.example
2761 (a) With no arguments, shows all currently-defined aliases.
2762 With one argument, shows that alias.
2763 With more than one argument,
2764 creates a new alias or appends to an existing one.
2766 can be used to delete aliases.
2770 (alt) Manage a list of alternate addresses / names of the active user,
2771 members of which will be removed from recipient lists when replying to
2774 variable is not set).
2775 If arguments are given the set of alternate names is replaced by them,
2776 without arguments the current set is displayed.
2780 Takes a message list and marks each message as having been answered.
2781 This mark has no technical meaning in the mail system;
2782 it just causes messages to be marked in the header summary,
2783 and makes them specially addressable.
2787 Calls a macro that has been created via
2792 (ch) Change the working directory to
2794 or the given argument.
2800 \*(OP Only applicable to S/MIME signed messages.
2801 Takes a message list and a file name and saves the certificates
2802 contained within the message signatures to the named file in both
2803 human-readable and PEM format.
2804 The certificates can later be used to send encrypted messages to the
2805 respective message senders by setting
2806 .Va smime-encrypt-USER@HOST
2811 (ch) Change the working directory to
2813 or the given argument.
2819 Only applicable to threaded mode.
2820 Takes a message list and makes all replies to these messages invisible
2821 in header summaries, unless they are in state
2827 \*(OP\*(NQ Manage colour mappings for the type of colour given as the
2828 (case-insensitive) first argument, which must be one of
2830 for 256-colour terminals,
2835 for the standard 8-colour ANSI / ISO 6429 color palette and
2839 for monochrome terminals.
2840 Monochrome terminals cannot deal with colours, but only (some) font
2844 Without further arguments the list of all currently defined mappings
2845 for the given colour type is shown (as a special case giving
2849 will iterate over all types in order).
2850 Otherwise the second argument defines the mappable slot, the third
2851 argument a (comma-separated list of) colour and font attribute
2852 specification(s), and the optional fourth argument can be used to
2853 specify a precondition: if conditioned mappings exist they are tested in
2854 (creation) order unless a (case-insensitive) match has been found, and
2855 the default mapping (if any has been established) will only be chosen as
2857 The types of precondition available depend on the mappable slot, the
2858 following of which exist:
2861 Mappings prefixed with
2863 are used for the \*(OPal builtin Mailx-Line-Editor (MLE, see
2864 .Sx "On terminal control and line editor" )
2865 and don't support preconditions.
2867 .Bl -tag -compact -width view-partinfo
2869 This mapping is used for the position indicator that is visible when
2870 a line cannot be fully displayed on the screen.
2877 Mappings prefixed with
2879 are used in header summaries, and they all understand the preconditions
2881 (the current message) and
2883 for elder messages (only honoured in conjunction with
2884 .Va datefield-markout-older ) .
2886 .Bl -tag -compact -width view-partinfo
2888 This mapping is used for the
2890 that can be created with the
2894 formats of the variable
2897 For the complete header summary line except the
2899 and the thread structure.
2901 For the thread structure which can be created with the
2903 format of the variable
2908 Mappings prefixed with
2910 are used when displaying messages.
2912 .Bl -tag -compact -width view-partinfo
2914 This mapping is used for so-called
2916 lines, which are MBOX file format specific header lines.
2919 A comma-separated list of headers to which the mapping applies may be
2920 given as a precondition; if the \*(OPal regular expression support is
2921 available then if any of the
2923 (extended) regular expression characters is seen the precondition will
2924 be evaluated as (an extended) one.
2926 For the introductional message info line.
2927 .It Cd view-partinfo
2928 For MIME part info lines.
2932 The following (case-insensitive) colour definitions and font attributes
2933 are understood, multiple of which can be specified in a comma-separated
2943 It is possible (and often applicable) to specify multiple font
2944 attributes for a single mapping.
2947 foreground colour attribute:
2957 To specify a 256-color mode a decimal number colour specification in
2958 the range 0 to 255, inclusive, is supported, and interpreted as follows:
2960 .Bl -tag -compact -width "999 - 999"
2962 the standard ISO 6429 colors, as above.
2964 high intensity variants of the standard colors.
2966 216 colors in tuples of 6.
2968 grayscale from black to white in 24 steps.
2970 .Bd -literal -offset indent
2972 fg() { printf "\e033[38;5;${1}m($1)"; }
2973 bg() { printf "\e033[48;5;${1}m($1)"; }
2975 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
2976 printf "\e033[0m\en"
2978 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
2979 printf "\e033[0m\en"
2983 background colour attribute (see
2985 for possible values).
2989 Mappings may be removed with the command
2991 For a generic overview see the section
2992 .Sx "Coloured display" .
2997 (C) Copy messages to files whose names are derived from the author of
2998 the respective message and don't mark them as being saved;
2999 otherwise identical to
3004 (c) Copy messages to the named file and don't mark them as being saved;
3005 otherwise identical to
3010 \*(NQ With no arguments, shows all currently-defined custom headers.
3011 With one argument, shows that custom header.
3012 With more than one argument, creates a new or replaces an existing
3013 custom header with the name given as the first argument, the content of
3014 which being defined by the concatenated remaining arguments.
3016 can be used to delete custom headers.
3017 \*(ID Overwriting of automatically managed headers is neither supported
3019 Defined custom headers will be injected into newly composed or forwarded
3022 .Dl customhdr OpenPGP id=12345678; url=http://www.YYY.ZZ
3026 may also be used to inject custom headers; it is covered by
3031 Show the name of the current working directory.
3035 \*(OP For unencrypted messages this command is identical to
3037 Encrypted messages are first decrypted, if possible, and then copied.
3041 \*(OP For unencrypted messages this command is identical to
3043 Encrypted messages are first decrypted, if possible, and then copied.
3047 Without arguments the current list of macros, including their content,
3048 is shown, otherwise a macro is defined.
3049 A macro definition is a sequence of commands in the following form:
3050 .Bd -literal -offset indent
3059 A defined macro can be invoked explicitly by using the
3063 commands, or implicitly if a macro hook is triggered, e.g., a
3065 Note that interpretation of
3067 depends on how (i.e.,
3069 normal macro, folder hook, hook, account switch) the macro is invoked.
3070 Macros can be deleted via
3074 Macro behaviour, including option localization, will change in v15.
3075 Please be aware of that and possibly embed a version check in a resource
3080 (d) Marks the given message list as
3082 Deleted messages will neither be saved in
3084 nor will they be available for most other commands.
3096 Deletes the current message and displays the next message.
3097 If there is no next message, \*(UA says
3104 up or down by one message when given
3108 argument, respectively.
3112 Takes a message list and marks each given message as a draft.
3113 This mark has no technical meaning in the mail system;
3114 it just causes messages to be marked in the header summary,
3115 and makes them specially addressable.
3119 (ec) Echoes its arguments after applying
3121 expansions and filename transformations, as documented for
3126 (e) Point the text editor (as defined in
3128 at each message from the given list in turn.
3129 Modified contents are discarded unless the
3136 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3137 conditional \(em if the condition of a preceeding
3139 was false, check the following condition and execute the following block
3140 if it evaluates true.
3145 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3146 conditional \(em if none of the conditions of the preceeding
3150 commands was true, the
3156 (en) Marks the end of an
3157 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3158 conditional execution block.
3163 \*(NQ \*(UA has a strict notion about which variables are
3164 .Sx "INTERNAL VARIABLES"
3165 and which are managed in the program
3167 Since some of the latter are a vivid part of \*(UAs functioning,
3168 however, they are transparently integrated into the normal handling of
3169 internal variables via
3173 To integrate other environment variables of choice into this
3174 transparent handling, and also to export internal variables into the
3175 process environment where they normally are not, a
3177 needs to become established with this command, as in, e.g.,
3180 .Dl environ link PERL5LIB from TZ
3183 Afterwards changing such variables with
3185 will cause automatic updates of the program environment, and therefore
3186 be inherited by newly created child processes.
3187 Sufficient system support provided (it was in BSD as early as 1987, and
3188 is standardized since Y2K) removing such variables with
3190 will remove them also from the program environment, but in any way
3191 the knowledge they ever have been
3194 Note this implies that
3196 may cause loss of links.
3201 will remove an existing link, but leaves the variables as such intact.
3202 Additionally the subcommands
3206 are provided, which work exactly the same as the documented commands
3210 but (additionally) link the variable(s) with the program environment and
3211 thus immediately export them to, or remove them from (if possible),
3212 respectively, the program environment.
3217 \*(OP Since \*(UA uses the console as a user interface it can happen
3218 that messages scroll by too fast to become recognized.
3219 Optionally an error message ring queue is available which stores
3220 duplicates of any error message and notifies the user in interactive
3221 sessions whenever a new error has occurred.
3222 The queue is finite: if its maximum size is reached any new message
3223 replaces the eldest.
3226 can be used to manage this message queue: if given
3228 or no argument the queue will be displayed and cleared,
3230 will only clear all messages from the queue.
3234 (ex or x) Exit from \*(UA without changing the active mailbox and skip
3235 any saving of messages in
3237 as well as a possibly tracked line editor history file.
3241 Show the list of features that have been compiled into \*(UA.
3242 (Outputs the contents of the variable
3249 but open the mailbox readonly.
3253 (fi) The file command switches to a new mailbox.
3254 Without arguments it shows status information of the current mailbox.
3255 If an argument is given, it will write out changes (such as deletions)
3256 the user has made and open a new mailbox.
3257 Some special conventions are recognized for the
3261 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
3263 (number sign) means the previous file,
3265 (percent sign) means the invoking user's system
3269 means the primary system mailbox of
3271 (and never the value of
3273 regardless of its actual setting),
3275 (ampersand) means the invoking user's
3285 expands to the same value as
3287 but the file is handled as a primary system mailbox by, e.g., the
3291 commands, meaning that messages that have been read in the current
3292 session will be moved to the
3294 mailbox instead of simply being flagged as read.
3297 If the name matches one of the strings defined with the command
3299 it is replaced by its long form and expanded.
3300 If the name ends with
3305 it is treated as being compressed with
3310 respectively, and transparently handled through an intermediate
3311 (un)compression step (using a temporary file) with the according
3312 facility, sufficient support provided.
3313 Likewise, if the named file doesn't exist, but a file with one of the
3314 mentioned compression extensions does, then the name is automatically
3315 expanded and the compressed file is used.
3317 Otherwise, if the name ends with an extension for which
3318 .Va file-hook-load-EXTENSION
3320 .Va file-hook-save-EXTENSION
3321 variables are set, then the given hooks will be used to load and save
3323 and \*(UA will work with an intermediate temporary file.
3325 MBOX files (flat file-based mailboxes) are generally locked during file
3326 operations in order to avoid inconsistencies due to concurrent
3328 \*(OPal Mailbox files which \*(UA treats as system
3330 boxes or primary mailboxes will also be protected by so-called dotlock
3331 files, the traditional way of mail spool file locking: for any file
3335 will be created for the duration of the synchronization \(em
3336 as necessary a privilege-separated dotlock child process will be used
3337 to accommodate for necessary privilege adjustments in order to create
3338 the dotlock file in the same directory
3339 and with the same user and group identities as the file of interest.
3342 for fine-tuning the handling of MBOX files.
3346 refers to a directory with the subdirectories
3351 then it is treated as a folder in
3353 format; \*(ID the variable
3355 can be used to control the format of yet non-existent folders.
3358 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3359 .Dl \*(OU protocol://[user@]host[:port][/path]
3361 is taken as an Internet mailbox specification.
3362 The \*(OPally supported protocols are
3366 (POP3 with SSL/TLS encrypted transport).
3369 part is valid only for IMAP; there it defaults to
3371 Also see the section
3372 .Sx "On URL syntax and credential lookup" .
3376 contains special characters, in particular
3380 they must be escaped in URL notation \(en the command
3382 can be used to show the necessary conversion.
3386 Takes a message list and marks the messages as
3388 ged for urgent/special attention.
3389 This mark has no technical meaning in the mail system;
3390 it just causes messages to be highlighted in the header summary,
3391 and makes them specially addressable.
3400 With no arguments, list the names of the folders in the folder directory.
3401 With an existing folder as an argument,
3402 lists the names of folders below the named folder.
3408 but saves the message in a file named after the local part of the first
3409 recipient's address (instead of in
3416 but saves the message in a file named after the local part of the first
3417 recipient's address (instead of in
3424 but responds to all recipients regardless of the
3429 .It Ic followupsender
3432 but responds to the sender only regardless of the
3448 (f) Takes a list of message specifications and displays a summary of
3449 their message headers, as via
3451 An alias of this command is
3454 .Sx "Specifying messages" .
3460 but saves the message in a file named after the local part of the
3461 recipient's address (instead of in
3466 Takes a message and the address of a recipient
3467 and forwards the message to him.
3468 The text of the original message is included in the new one,
3469 with the value of the
3471 variable preceding it.
3476 commands specify which header fields are included in the new message.
3477 Only the first part of a multipart message is included unless the
3478 .Va forward-as-attachment
3482 is set recipient addresses will be stripped from comments, names etc.
3486 Specifies which header fields are to be ignored with the command
3488 This command has no effect when the
3489 .Va forward-as-attachment
3494 Specifies which header fields are to be retained with the command
3499 This command has no effect when the
3500 .Va forward-as-attachment
3505 Define or list command aliases, so-called ghosts.
3506 Without arguments a list of all currently known aliases is shown.
3507 With one argument the expansion of the given alias is shown.
3508 With two or more arguments a command alias is defined or updated: the
3509 first argument is the name under which the remaining command line should
3510 be accessible, the content of which can be just about anything.
3511 A ghost can be used everywhere a normal command can be used, but always
3512 takes precedence; any arguments that are given to the command alias are
3513 joined onto the alias content, and the resulting string forms the
3514 command line that is, in effect, executed.
3517 .Bd -literal -offset indent
3519 `ghost': no such alias: "xx"
3522 ghost xx "echo hello,"
3531 (h) Show the current group of headers, the size of which depends on
3534 and the style of which can be adjusted with the variable
3536 If a message-specification is given the group of headers containing the
3537 first message therein is shown and the message at the top of the screen
3552 the list of history entries;
3555 argument selects and shows the respective history entry \(en
3558 to accept it, and the history entry will become the new history top.
3559 The default mode if no arguments are given is
3566 Takes a message list and marks each message therein to be saved in the
3571 Does not override the
3574 \*(UA deviates from the POSIX standard with this command, because a
3576 command issued after
3578 will display the following message, not the current one.
3583 (i) Part of the nestable
3584 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3585 conditional execution construct \(em if the given condition is true then
3586 the encapsulated block is executed.
3587 POSIX only supports the (case-insensitive) conditions
3592 end, all remaining conditions are non-portable extensions; note that
3593 falsely specified conditions cause the execution of the entire
3594 conditional construct until the (matching) closing
3596 command to be suppressed.
3597 The syntax of the nestable
3599 conditional execution construct requires that each condition and syntax
3600 element is surrounded by whitespace.
3602 .Bd -literal -offset indent
3611 The (case-insensitive) condition
3613 erminal will evaluate to true if the standard input is a terminal, i.e.,
3614 in interactive sessions.
3615 Another condition can be any boolean value (see the section
3616 .Sx "INTERNAL VARIABLES"
3617 for textual boolean representations) to mark an enwrapped block as
3620 .Dq always execute .
3621 It is possible to check
3622 .Sx "INTERNAL VARIABLES"
3625 variables for existence or compare their expansion against a user given
3626 value or another variable by using the
3628 .Pf ( Dq variable next )
3629 conditional trigger character;
3630 a variable on the right hand side may be signalled using the same
3632 The variable names may be enclosed in a pair of matching braces.
3635 The available comparison operators are
3639 (less than or equal to),
3645 (greater than or equal to),
3649 (is substring of) and
3651 (is not substring of).
3652 The values of the left and right hand side are treated as strings and
3653 are compared 8-bit byte-wise, ignoring case according to the rules of
3654 the US-ASCII encoding (therefore, dependend on the active locale,
3655 possibly producing false results for strings in the locale encoding).
3656 Except for the substring checks the comparison will instead be performed
3657 arithmetically if both, the user given value as well as the variable
3658 content, can be parsed as numbers (integers).
3659 An unset variable is treated as the empty string.
3662 When the \*(OPal regular expression support is available, the additional
3668 They treat the right hand side as an extended regular expression that is
3669 matched case-insensitively and according to the active
3671 locale, meaning that strings in the locale encoding should be matched
3675 Conditions can be joined via AND-OR lists (where the AND operator is
3677 and the OR operator is
3679 which have equal precedence and will be evaluated with left
3680 associativity, thus using the same syntax that is known for the
3682 It is also possible to form groups of conditions and lists by enclosing
3683 them in pairs of brackets
3684 .Ql [\ \&.\&.\&.\ ] ,
3685 which may be interlocked within each other, and also be joined via
3689 The results of individual conditions and entire groups may be modified
3690 via unary operators: the unary operator
3692 will reverse the result.
3694 .Bd -literal -offset indent
3698 if $ttycharset == "UTF-8"
3699 echo *ttycharset* is set to UTF-8, case-insensitively
3703 echo These two variables are equal
3705 if $version-major >= 15
3706 echo Running a new version..
3707 if $features =@ "regex"
3708 if $TERM =~ "^xterm\&.*"
3709 echo ..in an X terminal
3712 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
3715 if true && $debug || ${verbose}
3716 echo Left associativity, as is known from the shell
3718 if ! ! true && ! [ ! $debug && ! $verbose ]
3719 echo Unary operator support
3727 Without arguments the list of ignored header fields is shown,
3728 otherwise the given list of header fields is added to the ignore list:
3729 Header fields in the ignore list are not shown on the terminal when
3730 a message is displayed.
3731 To display a message in its entirety, use the commands
3742 Shows the names of all available commands, alphabetically sorted.
3743 If given any non-whitespace argument the list will be shown in the order
3744 in which command prefixes are searched.
3748 This command can be used to localize changes to variables, meaning that
3749 their state will be reverted to the former one once the covered scope
3751 It can only be used inside of macro definition blocks introduced by
3755 and is interpreted as a boolean (string, see
3756 .Sx "INTERNAL VARIABLES" ) ;
3759 of an account is left once it is switched off again.
3760 .Bd -literal -offset indent
3761 define temporary_settings {
3776 enables change localization and calls
3778 which explicitly resets localization, then any value changes within
3780 will still be reverted by
3782 \*(ID Once the outermost level, the one which enabled localization
3783 first, is left, but no earlier, all adjustments will be unrolled.
3787 Reply to messages that come in via known
3790 .Pf ( Ic mlsubscribe )
3791 mailing lists, or pretend to do so (see
3792 .Sx "Mailing lists" ) :
3795 functionality this will actively resort and even remove message
3796 recipients in order to generate a message that is supposed to be sent to
3798 For example it will also implicitly generate a
3799 .Ql Mail-Followup-To:
3800 header if that seems useful, regardless of the setting of the variable
3807 but saves the message in a file named after the local part of the first
3808 recipient's address (instead of in
3813 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3814 or asks on standard input if none were given;
3815 then collects the remaining mail content and sends it out.
3819 (mb) The given message list is to be sent to
3821 when \*(UA is quit; this is the default action unless the
3824 \*(ID This command can only be used in a primary system mailbox (see
3829 Without any arguments the content of the MIME type cache will displayed.
3830 Otherwise each argument defines a complete MIME type specification of
3831 a type that shall be added (prepended) to the cache.
3832 In any event MIME type sources are loaded first as necessary \(en
3833 .Va mimetypes-load-control
3834 can be used to fine-tune which sources are actually loaded.
3835 Refer to the section on
3836 .Sx "The mime.types files"
3837 for more on MIME type specifications and this topic in general.
3838 MIME type unregistration and cache resets can be triggered with
3843 Without arguments the list of all currently defined mailing lists
3844 (and their attributes, if any) is shown; a more verbose listing will be
3845 produced if either of
3850 Otherwise all given arguments (which need not be quoted except for
3851 whitespace) will be added and henceforth be recognized as mailing lists.
3852 Mailing lists may be removed via the command
3855 If the \*(OPal regular expression support is available then mailing
3856 lists may also be specified as (extended) regular expressions (see
3862 Without arguments the list of all currently defined mailing lists which
3863 have a subscription attribute is shown; a more verbose listing will be
3864 produced if either of
3869 Otherwise this attribute will be set for all given mailing lists,
3870 newly creating them as necessary (as via
3872 Subscription attributes may be removed via the command
3881 but moves the messages to a file named after the local part of the
3882 sender address of the first message (instead of in
3889 but marks the messages for deletion if they were transferred
3896 but also displays ignored header fields and all MIME parts.
3904 on the given messages, even in non-interactive mode and as long as the
3905 standard output is a terminal.
3911 \*(OP When used without arguments or if
3913 has been given the content of the
3915 cache is shown, loading it first as necessary,
3918 then the cache will only be initialized and
3920 will remove its contents.
3921 Note that \*(UA will try to load the file only once, use
3922 .Ql Ic \&\&netrc Ns \:\0\:clear
3923 to unlock further attempts.
3927 .Sx "On URL syntax and credential lookup" ;
3929 .Sx "The .netrc file"
3930 documents the file format in detail.
3934 Checks for new mail in the current folder without committing any changes
3936 If new mail is present, a message is shown.
3940 the headers of each new message are also shown.
3948 Goes to the next message in sequence and types it.
3949 With an argument list, types the next matching message.
3963 If the current folder is accessed via a network connection, a
3965 command is sent, otherwise no operation is performed.
3971 but also displays ignored header fields and all MIME parts.
3979 on the given messages, even in non-interactive mode and as long as the
3980 standard output is a terminal.
3988 but also pipes ignored header fields and all parts of MIME
3989 .Ql multipart/alternative
3994 (pi) Takes a message list and a shell command
3995 and pipes the messages through the command.
3996 Without an argument the current message is piped through the command
4003 every message is followed by a formfeed character.
4024 (q) Terminates the session, saving all undeleted, unsaved messages in
4027 preserving all messages marked with
4031 or never referenced in the system
4033 box, and removing all other messages from the primary system mailbox.
4034 If new mail has arrived during the session,
4036 .Dq You have new mail
4038 If given while editing a mailbox file with the command line flag
4040 then the edit file is rewritten.
4041 A return to the shell is effected,
4042 unless the rewrite of edit file fails,
4043 in which case the user can escape with the exit command.
4057 Removes the named files or directories.
4058 If a name refer to a mailbox, e.g., a Maildir mailbox, then a mailbox
4059 type specific removal will be performed, deleting the complete mailbox.
4060 The user is asked for confirmation in interactive mode.
4064 Takes the name of an existing folder
4065 and the name for the new folder
4066 and renames the first to the second one.
4067 Both folders must be of the same type.
4071 (R) Reply to originator.
4072 Does not reply to other recipients of the original message.
4074 will exchange this command with
4078 is set the recipient address will be stripped from comments, names etc.
4082 (r) Take a message and group-responds to it by addressing the sender
4085 .Va followup-to-honour ,
4088 .Va recipients-in-cc
4089 influence response behaviour.
4092 offers special support for replying to mailing lists.
4095 is set recipient addresses will be stripped from comments, names etc.
4108 but initiates a group-reply regardless of the value of
4115 but responds to the sender only regardless of the value of
4122 but does not add any header lines.
4123 This is not a way to hide the sender's identity,
4124 but useful for sending a message again to the same recipients.
4128 Takes a list of messages and a user name
4129 and sends each message to the named user.
4131 and related header fields are prepended to the new copy of the message.
4149 .It Ic respondsender
4155 (ret) Without arguments the list of retained header fields is shown,
4156 otherwise the given list of header fields is added to the retain list:
4157 Header fields in the retain list are shown on the terminal when
4158 a message is displayed, all other header fields are suppressed.
4159 To display a message in its entirety, use the commands
4168 takes precedence over the mentioned.
4174 but saves the messages in a file named after the local part of the
4175 sender of the first message instead of (in
4177 and) taking a filename argument.
4181 (s) Takes a message list and a filename and appends each message in turn
4182 to the end of the file.
4183 If no filename is given, the
4186 The filename in quotes, followed by the generated character count
4187 is echoed on the user's terminal.
4188 If editing a primary system mailbox the messages are marked for deletion.
4189 Filename interpretation as described for the
4191 command is performed.
4208 Header fields thus marked are filtered out when saving a message by
4210 or when automatically saving to
4212 This command should only be applied to header fields that do not contain
4213 information needed to decode the message,
4214 as MIME content fields do.
4226 Header fields thus marked are the only ones saved with a message when
4229 or when automatically saving to
4234 The use of this command is strongly discouraged since it may strip
4235 header fields that are needed to decode the message correctly.
4239 Takes a message specification (list) and displays a header summary of
4240 all matching messages, as via
4242 This command is an alias of
4245 .Sx "Specifying messages" .
4249 Takes a message list and marks all messages as having been read.
4253 (se) Without arguments this command shows all internal variables which
4254 are currently known to \*(UA (they have been set).
4255 A more verbose listing will be produced if either of
4259 are set, in which case variables may be preceeded with a comment line
4260 that gives some context of what \*(UA knows about the given variable.
4262 Otherwise the given variables (and arguments) are set or adjusted.
4263 Arguments are of the form
4265 (no space before or after
4269 if there is no value, i.e., a boolean variable.
4270 Quotation marks may be placed around any part of the assignment
4271 statement to quote blanks or tabs, e.g.,
4273 .Dl set indentprefix='->'
4275 If an argument begins with
4279 the effect is the same as invoking the
4281 command with the remaining part of the variable
4282 .Pf ( Ql unset save ) .
4286 that is known to map to an environment variable will automatically cause
4287 updates in the program environment (unsetting a variable in the
4288 environment requires corresponding system support).
4289 Please use the command
4291 for further environmental control.
4296 .Sx "INTERNAL VARIABLES"
4302 (sh) Invokes an interactive version of the shell.
4306 Without arguments the list of all currently defined shortcuts is
4308 Otherwise all given arguments (which need not be quoted except for
4309 whitespace) are treated as pairs of shortcuts and their expansions,
4310 creating new or changing already existing shortcuts, as necessary.
4311 Shortcuts may be removed via the command
4313 The expansion strings should be in the syntax that has been described
4322 but performs neither MIME decoding nor decryption, so that the raw
4323 message text is shown.
4327 (si) Shows the size in characters of each message of the given
4332 Shows the current sorting criterion when used without an argument.
4333 Otherwise creates a sorted representation of the current folder,
4336 command and the addressing modes such that they refer to messages in
4338 Message numbers are the same as in regular mode.
4342 a header summary in the new order is also displayed.
4343 Automatic folder sorting can be enabled by setting the
4345 variable, as in, e.g.,
4346 .Ql set autosort=thread .
4347 Possible sorting criterions are:
4349 .Bl -tag -compact -offset indent -width "subject"
4351 Sort the messages by their
4353 field, that is by the time they were sent.
4355 Sort messages by the value of their
4357 field, that is by the address of the sender.
4360 variable is set, the sender's real name (if any) is used.
4362 Sort the messages by their size.
4364 \*(OP Sort the message by their spam score, as has been classified by
4367 Sort the messages by their message status.
4369 Sort the messages by their subject.
4371 Create a threaded display.
4373 Sort messages by the value of their
4375 field, that is by the address of the recipient.
4378 variable is set, the recipient's real name (if any) is used.
4383 (so) The source command reads commands from the given file, which is
4384 subject to the usual filename expansions (see introductional words of
4386 If the given argument ends with a vertical bar
4388 then the argument will instead be interpreted as a shell command and
4389 \*(UA will read the output generated by it.
4392 cannot be used from within macros that execute as
4393 .Va folder-hook Ns s
4396 i.e., it can only be called from macros that were
4403 (beside not supporting pipe syntax a.k.a. shell command input) is that
4404 this command will not generate an error if the given file argument
4405 cannot be opened successfully.
4406 This can matter in, e.g., resource files, since loading of those is
4407 stopped when an error is encountered.
4411 \*(OP Takes a list of messages and clears their
4417 \*(OP Takes a list of messages and causes the
4419 to forget it has ever used them to train its Bayesian filter.
4420 Unless otherwise noted the
4422 flag of the message is inspected to chose wether a message shall be
4430 \*(OP Takes a list of messages and informs the Bayesian filter of the
4434 This also clears the
4436 flag of the messages in question.
4440 \*(OP Takes a list of messages and rates them using the configured
4441 .Va spam-interface ,
4442 without modifying the messages, but setting their
4444 flag as appropriate; because the spam rating headers are lost the rate
4445 will be forgotten once the mailbox is left.
4446 Refer to the manual section
4448 for the complete picture of spam handling in \*(UA.
4452 \*(OP Takes a list of messages and sets their
4458 \*(OP Takes a list of messages and informs the Bayesian filter of the
4464 flag of the messages in question.
4473 Create a threaded representation of the current folder,
4474 i.\|e. indent messages that are replies to other messages in the header
4475 display and change the
4477 command and the addressing modes such that they refer to messages in the
4479 Message numbers are the same as in unthreaded mode.
4483 a header summary in threaded order is also displayed.
4487 (to) Takes a message list and displays the top few lines of each.
4488 The number of lines shown is controlled by the variable
4493 (tou) Takes a message list and marks the messages for saving in
4495 \*(UA deviates from the POSIX standard with this command,
4498 command will display the following message instead of the current one.
4504 but also displays out ignored header fields and all parts of MIME
4505 .Ql multipart/alternative
4510 (t) Takes a message list and types out each message on the user's
4516 For MIME multipart messages, all parts with a content type of
4520 are shown, the other are hidden except for their headers.
4521 Messages are decrypted and converted to the terminal character set
4526 Delete all given accounts.
4527 An error message is shown if a given account is not defined.
4530 will discard all existing accounts.
4534 (una) Takes a list of names defined by alias commands
4535 and discards the remembered groups of users.
4538 will discard all existing aliases.
4542 Takes a message list and marks each message as not having been answered.
4546 Only applicable to threaded mode.
4547 Takes a message list and makes the message and all replies to it visible
4548 in header summaries again.
4549 When a message becomes the current message,
4550 it is automatically made visible.
4551 Also when a message with collapsed replies is displayed,
4552 all of these are automatically uncollapsed.
4558 mapping for the given colour type (see
4560 for a list of types) and mapping; if the optional precondition argument
4561 is used then only the exact tuple of mapping and precondition is removed.
4564 will remove all mappings (no precondition allowed).
4566 .Sx "Coloured display"
4567 for the general picture.
4571 Deletes the custom headers given as arguments.
4574 will remove all custom headers.
4578 Undefine all given macros.
4579 An error message is shown if a given macro is not defined.
4582 will discard all existing macros.
4586 (u) Takes a message list and marks each message as not being deleted.
4590 Takes a message list and
4596 Takes a message list and marks each message as not being
4601 Removes the header field names from the list of ignored fields for the
4606 will remove all fields.
4610 Removes the header field names from the list of retained fields for the
4615 will remove all fields.
4619 Remove all the given command
4623 will remove all ghosts.
4627 Removes the header field names from the list of ignored fields.
4630 will remove all fields.
4634 Delete all given MIME types, e.g.,
4635 .Ql unmimetype text/plain
4636 will remove all registered specifications for the MIME type
4640 will discard all existing MIME types, just as will
4642 but which also reenables cache initialization via
4643 .Va mimetypes-load-control .
4647 Forget about all the given mailing lists.
4650 will remove all lists.
4655 .It Ic unmlsubscribe
4656 Remove the subscription attribute from all given mailing lists.
4659 will clear the attribute from all lists which have it set.
4670 Takes a message list and marks each message as not having been read.
4674 Removes the header field names from the list of retained fields.
4677 will remove all fields.
4681 Removes the header field names from the list of ignored fields for
4685 will remove all fields.
4689 Removes the header field names from the list of retained fields for
4693 will remove all fields.
4697 (uns) Takes a list of internal variable names and discards their
4698 remembered values; the reverse of
4705 Deletes the shortcut names given as arguments.
4708 will remove all shortcuts.
4712 Disable sorted or threaded mode
4718 return to normal message order and,
4722 displays a header summary.
4732 Decode the given URL-encoded string arguments and show the results.
4733 Note the resulting strings may not be valid in the current locale, see
4738 URL-encode the given arguments and show the results.
4739 Because the arguments effectively are in the character set of the
4740 current locale the results will vary accordingly unless the input solely
4741 consists of characters in the portable character set, see
4742 .Sx "Character sets" .
4746 Edit the values of or create the given variable(s) in the
4748 Boolean variables cannot be edited.
4752 This command produces the same output as the listing mode of
4756 ity adjustments, but only for the given variables.
4760 \*(OP Takes a message list and verifies each message.
4761 If a message is not a S/MIME signed message,
4762 verification will fail for it.
4763 The verification process checks if the message was signed using a valid
4765 if the message sender's email address matches one of those contained
4766 within the certificate,
4767 and if the message content has been altered.
4771 (v) Takes a message list and invokes the display editor on each message.
4772 Modified contents are discarded unless the
4778 (w) For conventional messages the body without all headers is written.
4779 The output is decrypted and converted to its native format as necessary.
4780 If the output file exists, the text is appended.
4781 If a message is in MIME multipart format its first part is written to
4782 the specified file as for conventional messages,
4783 and the user is asked for a filename to save each other part.
4784 For convience saving of each part may be skipped by giving an empty value;
4785 the same result can also be achieved by writing it to
4787 For the second and subsequent parts a leading
4789 character causes the part to be piped to the remainder of the user input
4790 interpreted as a shell command;
4791 otherwise the user input is expanded as usually for folders,
4792 e.g., tilde expansion is performed.
4793 In non-interactive mode, only the parts of the multipart message
4794 that have a filename given in the part header are written,
4795 the others are discarded.
4796 The original message is never marked for deletion in the originating
4799 the contents of the destination file are overwritten if the file
4801 No special handling of compressed files is performed.
4810 \*(UA presents message headers in windowfuls as described under the
4813 This command scrolls to the next window of messages.
4814 If an argument is given,
4815 it specifies the window to use.
4816 A number prefixed by
4820 indicates that the window is calculated in relation to the current position.
4821 A number without a prefix specifies an absolute window number,
4824 lets \*(UA scroll to the last window of messages.
4830 but scrolls to the next or previous window that contains at least one
4839 .\" .Sh TILDE ESCAPES {{{
4842 Here is a summary of the tilde escapes,
4843 which are used to perform special functions when composing messages.
4844 Tilde escapes are only recognized at the beginning of lines.
4847 is somewhat of a misnomer since the actual escape character can be
4848 changed by adjusting the option
4851 .Bl -tag -width ".Ic __ filename"
4854 Insert the string of text in the message prefaced by a single
4856 (If the escape character has been changed,
4857 that character must be doubled
4858 in order to send it at the beginning of a line.)
4861 .It Ic ~! Ar command
4862 Execute the indicated shell
4864 then return to the message.
4868 Same effect as typing the end-of-file character.
4871 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4872 Execute the given \*(UA command.
4873 Not all commands, however, are allowed.
4877 Write a summary of command escapes.
4880 .It Ic ~< Ar filename
4885 .It Ic ~<! Ar command
4887 is executed using the shell.
4888 Its standard output is inserted into the message.
4891 .It Ic ~@ Op Ar filename...
4892 With no arguments, edit the attachment list interactively.
4893 If an attachment's file name is left empty,
4894 that attachment is deleted from the list.
4895 When the end of the attachment list is reached,
4896 \*(UA will ask for further attachments until an empty name is given.
4897 If a given file name solely consists of the number sign
4899 followed by a valid message number of the currently active mailbox, then
4900 the given message is attached as a MIME
4902 and the rest of this section does not apply.
4904 If character set conversion has been compiled into \*(UA, then this mode
4905 gives the user the option to specify input and output character sets,
4906 unless the file extension indicates binary content, in which case \*(UA
4907 asks wether this step shall be skipped for the attachment in question.
4908 If not skipped, then the charset that succeeds to represent the
4909 attachment data will be used in the
4911 MIME parameter of the mail message:
4913 .Bl -bullet -compact
4915 If input and output character sets are specified, then the conversion is
4916 performed on the fly.
4917 The user will be asked repeatedly until the desired conversion succeeds.
4919 If only an output character set is specified, then the input is assumed
4922 charset and will be converted to the given output charset on the fly.
4923 The user will be asked repeatedly until the desired conversion succeeds.
4925 If no character sets are specified at all then the algorithm that is
4926 documented in the section
4927 .Sx "Character sets"
4928 is applied, but directly and on the fly.
4929 The user will be asked repeatedly until the desired conversion succeeds.
4931 Finally, if an input-, but no output character set is specified, then no
4932 conversion is ever performed, but the
4934 MIME parameter value will still be set to the user input.
4936 The character set selection loop can be left by typing
4938 i.e., causing an interrupt.
4939 .\" \*(OU next sentence
4940 Note that before \*(UA version 15.0 this terminates the entire
4941 current attachment selection, not only the character set selection.
4944 Without character set conversion support, \*(UA will ask for the input
4945 character set only, and it'll set the
4947 MIME parameter value to the given input, if any;
4948 if no user input is seen then the
4950 character set will be used for the parameter value instead.
4951 Note that the file extension check isn't performed in this mode, since
4952 no conversion will take place anyway.
4954 Note that in non-interactive mode, for reproduceabilities sake, there
4955 will always be two questions for each attachment, regardless of wether
4956 character set conversion is available and what the file extension is.
4957 The first asks for the filename, and the second asks for the input
4958 character set to be passed through to the corresponding MIME parameter;
4959 no conversion will be tried if there is input to the latter question,
4960 otherwise the usual conversion algorithm, as above, is applied.
4961 For message attachments, the answer to the second question is completely
4966 arguments are specified for the
4968 command they are treated as a file list of
4970 -style quoted arguments, optionally also separated by commas, which are
4971 expanded and then appended to the existing list of message attachments.
4972 Message attachments can only be added via the first method.
4973 In this mode the (text) attachments are assumed to be in
4975 encoding, and will be evaluated as documented in the section
4976 .Sx "Character sets" .
4980 Inserts the string contained in the
4983 .Ql Ic ~i Ns \0Sign ) .
4984 The escape sequences tabulator
4992 Inserts the string contained in the
4995 .Ql Ic ~i Ns \0sign ) .
4996 The escape sequences tabulator
5003 .It Ic ~b Ar name ...
5004 Add the given names to the list of blind carbon copy recipients.
5007 .It Ic ~c Ar name ...
5008 Add the given names to the list of carbon copy recipients.
5012 Read the file specified by the
5014 variable into the message.
5018 Invoke the text editor on the message collected so far.
5019 After the editing session is finished,
5020 the user may continue appending text to the message.
5023 .It Ic ~F Ar messages
5024 Read the named messages into the message being sent, including all
5025 message headers and MIME parts.
5026 If no messages are specified, read in the current message.
5029 .It Ic ~f Ar messages
5030 Read the named messages into the message being sent.
5031 If no messages are specified, read in the current message.
5035 lists are used to modify the message headers.
5036 For MIME multipart messages,
5037 only the first displayable part is included.
5041 Edit the message header fields
5046 by typing each one in turn and allowing the user to edit the field.
5047 The default values for these fields originate from the
5055 Edit the message header fields
5061 by typing each one in turn and allowing the user to edit the field.
5064 .It Ic ~i Ar variable
5065 Insert the value of the specified variable into the message,
5066 adding a newline character at the end.
5067 The message remains unaltered if the variable is unset or empty.
5068 The escape sequences tabulator
5075 .It Ic ~M Ar messages
5076 Read the named messages into the message being sent,
5079 If no messages are specified, read the current message.
5082 .It Ic ~m Ar messages
5083 Read the named messages into the message being sent,
5086 If no messages are specified, read the current message.
5090 lists are used to modify the message headers.
5091 For MIME multipart messages,
5092 only the first displayable part is included.
5096 Display the message collected so far,
5097 prefaced by the message header fields
5098 and followed by the attachment list, if any.
5102 Abort the message being sent,
5103 copying it to the file specified by the
5110 .It Ic ~R Ar filename
5111 Read the named file into the message, indented by
5115 .It Ic ~r Ar filename
5116 Read the named file into the message.
5120 Cause the named string to become the current subject field.
5123 .It Ic ~t Ar name ...
5124 Add the given name(s) to the direct recipient list.
5127 .It Ic ~U Ar messages
5128 Read in the given / current message(s) excluding all headers, indented by
5132 .It Ic ~u Ar messages
5133 Read in the given / current message(s), excluding all headers.
5137 Invoke an alternate editor (defined by the
5139 option) on the message collected so far.
5140 Usually, the alternate editor will be a screen editor.
5141 After the editor is quit,
5142 the user may resume appending text to the end of the message.
5145 .It Ic ~w Ar filename
5146 Write the message onto the named file.
5148 the message is appended to it.
5154 except that the message is not saved at all.
5157 .It Ic ~| Ar command
5158 Pipe the message through the specified filter command.
5159 If the command gives no output or terminates abnormally,
5160 retain the original text of the message.
5163 is often used as a rejustifying filter.
5168 .\" .Sh INTERNAL VARIABLES {{{
5169 .Sh "INTERNAL VARIABLES"
5171 Internal \*(UA variables are controlled via the
5175 commands; prefixing a variable name with the string
5179 has the same effect as using
5185 Creation or editing of variables can be performed in the
5190 will give more insight on the given variable(s), and
5192 when called without arguments, will show a listing of all variables.
5193 Some well-known variables will also become inherited from the
5196 implicitly, others can be explicitly imported with the command
5198 and henceforth share the said properties.
5201 Two different kind of internal variables exist.
5202 There are boolean variables, which can only be in one of the two states
5206 and value variables with a(n optional) string value.
5207 For the latter proper quoting is necessary upon assignment time, the
5208 introduction of the section
5210 documents the supported quoting rules.
5212 .Bd -literal -offset indent
5213 wysh set one=val\e 1 two="val 2" \e
5214 three='val "3"' four=$'val \e'4\e''
5215 varshow one two three four
5216 unset one two three four
5220 Dependent upon the actual option the string values will be interpreted
5221 as numbers, colour names, normal text etc., but there also exists
5222 a special kind of string value, the
5223 .Dq boolean string ,
5224 which must either be a decimal integer (in which case
5228 and any other value is true) or any of the (case-insensitive) strings
5233 for a false boolean and
5238 for a true boolean; a special kind of boolean string is the
5240 which is a boolean string that can optionally be prefixed with the
5241 (case-insensitive) term
5245 which causes prompting of the user in interactive mode, with the given
5246 boolean as the default value.
5248 .\" .Ss "Initial settings" {{{
5249 .\" (Keep in SYNC: ./nail.h:okeys, ./nail.rc, ./nail.1:"Initial settings")
5250 .Ss "Initial Settings"
5252 The standard POSIX 2008/Cor 1-2013 mandates the following initial
5258 .Pf no Va autoprint ,
5272 .Pf no Va ignoreeof ,
5274 .Pf no Va keepsave ,
5276 .Pf no Va outfolder ,
5281 (note that \*(UA deviates from the standard by using
5285 special prompt escape results in
5293 .Pf no Va sendwait ,
5302 Notes: \*(UA doesn't support the
5304 variable \(en use command line options or
5305 .Va sendmail-arguments
5306 to pass options through to a MTA.
5307 And the default global
5309 file (which is loaded unless the
5311 command line flag has been used or the
5312 .Ev NAIL_NO_SYSTEM_RC
5313 environment variable is set) bends those initial settings a bit, e.g.,
5314 it sets the variables
5319 to name a few, calls
5321 etc., and should thus be taken into account.
5324 .\" .Ss "Variables" {{{
5327 .Bl -tag -width ".It Va _utoprin_"
5329 .It Va add-file-recipients
5330 \*(BO When file or pipe recipients have been specified,
5331 mention them in the corresponding address fields of the message instead
5332 of silently stripping them from their recipient list.
5333 By default such addressees are not mentioned.
5335 .Mx Va agent-shell-lookup
5336 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5338 \*(IN\*(OP Account passwords can be fetched via an external agent
5339 program in order to permit encrypted password storage \(en see
5340 .Sx "On URL syntax and credential lookup"
5341 for more on credential lookup.
5342 If this is set then the content is interpreted as a shell command the
5343 output of which (with newline characters removed) is treated as the
5344 account password shall the command succeed (and have produced non-empty
5345 non-newline output); e.g., via
5347 .Bd -literal -offset indent
5348 $ echo PASSWORD > .pass
5350 $ eval `gpg-agent --daemon \e
5351 --pinentry-program=/usr/bin/pinentry-curses \e
5352 --max-cache-ttl 99999 --default-cache-ttl 99999`
5353 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5357 A couple of environment variables will be set for the agent:
5359 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5361 The temporary directory that \*(UA uses.
5362 Usually identical to
5364 but guaranteed to be set and usable by child processes;
5365 to ensure the latter condition for
5371 for which the password is looked up.
5372 .It Ev NAIL_USER_ENC
5373 The URL percent-encoded variant of
5376 The plain machine hostname of the user account.
5377 .It Ev NAIL_HOST_PORT
5380 (hostname possibly including port) of the user account.
5385 \*(BO Causes only the local part to be evaluated
5386 when comparing addresses.
5390 \*(BO Causes messages saved in
5392 to be appended to the end rather than prepended.
5393 This should always be set.
5397 \*(BO Causes \*(UA to prompt for the subject of each message sent.
5398 If the user responds with simply a newline,
5399 no subject field will be sent.
5403 \*(BO Causes the prompts for
5407 lists to appear after the message has been edited.
5411 \*(BO If set, \*(UA asks for files to attach at the end of each message,
5412 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 carbon copy recipients
5418 (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 Causes the user to be prompted for blind carbon copy
5428 recipients (at the end of each message if
5432 are set) shall the list be found empty (at that time).
5433 An empty line finalizes the list.
5437 \*(BO\*(OP Causes the user to be prompted if the message is to be
5438 signed at the end of each message.
5441 variable is ignored when this variable is set.
5445 \*(BO Alternative name for
5452 .It Va attachment-ask-content-description , \
5453 attachment-ask-content-disposition , \
5454 attachment-ask-content-id , \
5455 attachment-ask-content-type
5456 \*(BO If set then the user will be prompted for some attachment
5457 information when editing the attachment list.
5458 It is advisable to not use these but for the first of the variables;
5459 even for that it has to be noted that the data is used
5465 A sequence of characters to display in the
5469 as shown in the display of
5471 each for one type of messages (see
5472 .Sx "Message states" ) ,
5473 with the default being
5476 .Ql NU\ \ *HMFAT+\-$~
5479 variable is set, in the following order:
5481 .Bl -tag -compact -offset indent -width ".It Ql _"
5503 start of a collapsed thread.
5505 an uncollapsed thread (TODO ignored for now).
5509 classified as possible spam.
5515 Specifies a list of recipients to which a blind carbon copy of each
5516 outgoing message will be sent automatically.
5520 Specifies a list of recipients to which a carbon copy of each outgoing
5521 message will be sent automatically.
5525 \*(BO Causes threads to be collapsed automatically when threaded mode
5532 \*(BO Causes the delete command to behave like
5534 thus, after deleting a message the next one will be typed automatically.
5538 \*(BO\*(OB Causes threaded mode (see the
5540 command) to be entered automatically when a folder is opened.
5542 .Ql autosort=thread .
5546 Causes sorted mode (see the
5548 command) to be entered automatically with the value of this option as
5549 sorting method when a folder is opened, e.g.,
5550 .Ql set autosort=thread .
5554 \*(BO Enables the substitution of
5556 by the contents of the last command line in shell escapes.
5559 .It Va batch-exit-on-error
5560 \*(BO If the batch mode has been enabled via the
5562 command line option, then this variable will be consulted whenever \*(UA
5563 completes one operation (returns to the command prompt); if it is set
5564 then \*(UA will terminate if the last operation generated an error.
5568 \*(BO Causes automatic display of a header summary after executing a
5574 \*(BO Sets some cosmetical features to traditional BSD style;
5575 has the same affect as setting
5577 and all other variables prefixed with
5579 it also changes the meaning of the \*(UA specific
5582 escape sequence and changes behaviour of
5584 (which doesn't exist in BSD).
5588 \*(BO Changes the letters shown in the first column of a header
5589 summary to traditional BSD style.
5593 \*(BO Changes the display of columns in a header summary to traditional
5598 \*(BO Changes some informational messages to traditional BSD style.
5604 field to appear immediately after the
5606 field in message headers and with the
5608 .Sx "TILDE ESCAPES" .
5612 The value that should appear in the
5616 MIME header fields when no character set conversion of the message data
5618 This defaults to US-ASCII, and the chosen character set should be
5619 US-ASCII compatible.
5623 \*(OP The default 8-bit character set that is used as an implicit last
5624 member of the variable
5626 This defaults to UTF-8.
5627 If no character set conversion capabilities are available in \*(UA then
5628 the only supported character set is
5630 Refer to the section
5631 .Sx "Character sets"
5632 for the complete picture of character set conversion in \*(UA.
5635 .It Va charset-unknown-8bit
5636 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5638 the content of a mail message by using a character set with the name
5640 Because of the unclassified nature of this character set \*(UA will not
5641 be capable to convert this character set to any other character set.
5642 If this variable is set any message part which uses the character set
5644 is assumed to really be in the character set given in the value,
5645 otherwise the (final) value of
5647 is used for this purpose.
5649 This variable will also be taken into account if a MIME type (see
5650 .Sx "The mime.types files" )
5651 of a MIME message part that uses the
5653 character set is forcefully treated as text.
5657 The default value for the
5662 .It Va colour-disable
5663 \*(BO\*(OP Forcefully disable usage of colours.
5664 Also see the section
5665 .Sx "Coloured display" .
5669 \*(BO\*(OP Wether colour shall be used for output that is paged through
5671 Note that pagers may need special flags, e.g.,
5679 in order to support colours.
5680 Often doing manual adjustments is unnecessary since \*(UA may perform
5681 adjustments dependend on the value of the environment variable
5683 (see there for more).
5687 In a(n interactive) terminal session, then if this valued option is set
5688 it'll be used as a threshold to determine how many lines the given
5689 output has to span before it will be displayed via the configured
5693 can be forced by setting this to the value
5695 setting it without a value will deduce the current height of the
5696 terminal screen to compute the treshold (see
5704 \*(OB A variable counterpart of the
5706 command (see there for documentation), interpreted as a comma-separated
5707 list of custom headers to be injected, to include commas in the header
5708 bodies escape them with backslash, e.g.:
5710 .Dl set customhdr='Hdr1: Body1-1\e, Body1-2, Hdr2: Body2'
5716 the message date, if any is to be displayed according to the format of
5718 is by default taken from the
5720 line of the message.
5721 If this variable is set the date as given in the
5723 header field is used instead, converted to local time.
5724 To control the display format of the date assign a valid
5729 format should not be used, because \*(UA doesn't take embedded newlines
5730 into account when calculating how many lines fit onto the screen.)
5732 .Va datefield-markout-older .
5735 .It Va datefield-markout-older
5736 This option, when set in addition to
5740 messages (concept is rather comparable to the
5742 option of the POSIX utility
5744 The content interpretation is identical to
5749 \*(BO Enables debug messages and obsoletion warnings, disables the
5750 actual delivery of messages and also implies
5756 .It Va disposition-notification-send
5758 .Ql Disposition-Notification-To:
5759 header (RFC 3798) with the message.
5763 .\" TODO .It Va disposition-notification-send-HOST
5765 .\".Va disposition-notification-send
5766 .\" for SMTP accounts on a specific host.
5767 .\" TODO .It Va disposition-notification-send-USER@HOST
5769 .\".Va disposition-notification-send
5770 .\"for a specific account.
5774 \*(BO When dot is set, a period
5776 on a line by itself during message input in (interactive) compose mode
5777 will be treated as end-of-message (in addition to the normal end-of-file
5786 .It Va dotlock-ignore-error
5787 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5788 mailboxes (see the command
5790 will be protected with so-called dotlock files\(emthe traditional mail
5791 spool file locking method\(emin addition to system file locking.
5792 Because \*(UA ships with a privilege-separated dotlock creation program
5793 that should always be able to create such a dotlock file there is no
5794 good reason to ignore dotlock file creation errors, and thus these are
5795 fatal unless this variable is set.
5799 \*(BO If this variable is set then the editor is started automatically
5800 when a message is composed in interactive mode, as if the
5806 variable is implied for this automatically spawned editor session.
5810 \*(BO When a message is edited while being composed,
5811 its header is included in the editable text.
5821 fields are accepted within the header, other fields are ignored.
5825 \*(BO When entering interactive mode \*(UA normally writes
5826 .Dq \&No mail for user
5827 and exits immediately if a mailbox is empty or doesn't exist.
5828 If this option is set \*(UA starts even with an empty or nonexistent
5829 mailbox (the latter behaviour furtherly depends upon
5835 Suggestion for the MIME encoding to use in outgoing text messages
5837 Valid values are the default
5838 .Ql quoted-printable ,
5843 may cause problems when transferring mail messages over channels that
5844 are not ESMTP (RFC 1869) compliant.
5845 If there is no need to encode a message,
5847 transfer mode is always used regardless of this variable.
5848 Binary data is always encoded as
5853 If defined, the first character of this option
5854 gives the character to use in place of
5857 .Sx "TILDE ESCAPES" .
5861 If not set then file and command pipeline targets are not allowed,
5862 and any such address will be filtered out, giving a warning message.
5863 If set without a value then all possible recipient address
5864 specifications will be accepted \(en see the section
5865 .Sx "On sending mail, and non-interactive mode"
5867 To accept them, but only in interactive mode, or when tilde commands
5868 were enabled explicitly by using one of the command line options
5872 set this to the (case-insensitive) value
5874 (note right now this is actually like setting
5875 .Ql restrict,-all,+name,+addr ) .
5877 In fact the value is interpreted as a comma-separated list of values.
5880 then the existence of disallowed specifications is treated as a hard
5881 send error instead of only filtering them out.
5882 The remaining values specify wether a specific type of recipient
5883 address specification is allowed (optionally indicated by a plus sign
5885 prefix) or disallowed (prefixed with a hyphen
5889 addresses all possible address specifications,
5893 command pipeline targets,
5895 plain user names and (MTA) aliases (\*(OB
5897 may be used as an alternative syntax to
5902 These kind of values are interpreted in the given order, so that
5903 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5904 will cause hard errors for any non-network address recipient address
5905 unless \*(UA is in interactive mode or has been started with the
5909 command line option; in the latter case(s) any address may be used, then.
5913 Unless this variable is set additional mail-transfer-agent (MTA)
5914 arguments from the command line, as can be given after a
5916 separator, are ignored due to safety reasons.
5917 However, if set to the special (case-insensitive) value
5919 then the presence of additional MTA arguments is treated as a hard
5920 error that causes \*(UA to exit with failure status.
5921 A lesser strict variant is the otherwise identical
5923 which does accept such arguments in interactive mode, or if tilde
5924 commands were enabled explicitly by using one of the command line options
5931 \*(RO Information on the features compiled into \*(UA \(en the content
5932 of this variable is identical to the output of the command
5937 \*(BO This option reverses the meanings of a set of reply commands,
5938 turning the lowercase variants, which by default address all recipients
5939 included in the header of a message
5940 .Pf ( Ic reply , respond , followup )
5941 into the uppercase variants, which by default address the sender only
5942 .Pf ( Ic Reply , Respond , Followup )
5945 .Ic replysender , respondsender , followupsender
5947 .Ic replyall , respondall , followupall
5948 are not affected by the current setting of
5953 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5954 It is possible to install file hooks which will be used by the
5956 command in order to be able to transparently handle (through an
5957 intermediate temporary file) files with specific
5959 s: the variable values can include shell snippets and are expected to
5960 write data to standard output / read data from standard input,
5962 \*(ID The variables may not be changed while there is a mailbox
5964 .Bd -literal -offset indent
5965 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5966 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5967 record=+null-sent.xy
5972 The default path under which mailboxes are to be saved:
5973 file names that begin with the plus-sign
5975 will be expanded by prefixing them with the value of this variable.
5976 The same special syntax conventions as documented for the
5978 command may be used; if the non-empty value doesn't start with a slash
5982 will be prefixed automatically.
5983 If unset or the empty string any
5985 prefixing file names will remain unexpanded.
5989 This variable can be set to the name of a
5991 macro which will be called whenever a
5994 The macro will also be invoked when new mail arrives,
5995 but message lists for commands executed from the macro
5996 only include newly arrived messages then.
5998 are activated by default in a folder hook, causing the covered settings
5999 to be reverted once the folder is left again.
6002 Macro behaviour, including option localization, will change in v15.
6003 Please be aware of that and possibly embed a version check in a resource
6007 .It Va folder-hook-FOLDER
6012 Unlike other folder specifications, the fully expanded name of a folder,
6013 without metacharacters, is used to avoid ambiguities.
6014 However, if the mailbox resides under
6018 specification is tried in addition, e.g., if
6022 (and thus relative to the user's home directory) then
6023 .Pa /home/usr1/mail/sent
6025 .Ql folder-hook-/home/usr1/mail/sent
6026 first, but then followed by
6027 .Ql folder-hook-+sent .
6031 \*(BO Controls wether a
6032 .Ql Mail-Followup-To:
6033 header is generated when sending messages to known mailing lists.
6035 .Va followup-to-honour
6037 .Ic mlist , mlsubscribe , reply
6042 .It Va followup-to-honour
6044 .Ql Mail-Followup-To:
6045 header is honoured when group-replying to a message via
6049 This is a quadoption; if set without a value it defaults to
6059 .It Va forward-as-attachment
6060 \*(BO Original messages are normally sent as inline text with the
6063 and only the first part of a multipart message is included.
6064 With this option messages are sent as unmodified MIME
6066 attachments with all of their parts included.
6070 The address (or a list of addresses) to put into the
6072 field of the message header, quoting RFC 5322:
6073 the author(s) of the message, that is, the mailbox(es) of the person(s)
6074 or system(s) responsible for the writing of the message.
6075 If replying to messages these addresses are handled as if they were in
6079 If the machine's hostname is not valid at the Internet (for example at
6080 a dialup machine) then either this variable or
6085 adds even more fine-tuning capabilities),
6089 contains more than one address,
6092 variable is required (according to the standard RFC 5322).
6096 \*(BO When replying to or forwarding a message \*(UA normally removes
6097 the comment and name parts of email addresses.
6098 If this variable is set such stripping is not performed,
6099 and comments, names etc. are retained.
6103 The string to put before the text of a message with the
6107 .Va forward-as-attachment
6110 .Dq -------- Original Message --------
6111 if unset; No heading is put if it is set to the empty string.
6115 \*(BO Causes the header summary to be written at startup and after
6116 commands that affect the number of messages or the order of messages in
6117 the current folder; enabled by default.
6118 The command line option
6126 A format string to use for the summary of
6128 similar to the ones used for
6131 Format specifiers in the given string start with a percent character
6133 and may be followed by an optional decimal number indicating the field
6134 width \(em if that is negative, the field is to be left-aligned.
6135 Valid format specifiers are:
6138 .Bl -tag -compact -offset indent -width "_%%_"
6140 A plain percent character.
6143 a space character but for the current message
6145 for which it expands to
6149 a space character but for the current message
6151 for which it expands to
6154 \*(OP The spam score of the message, as has been classified via the
6157 Shows only a replacement character if there is no spam support.
6159 Message attribute character (status flag); the actual content can be
6163 The date when the message was received, or the date found in the
6167 variable is set (optionally to a date display format string).
6169 The indenting level in threaded mode.
6171 The address of the message sender.
6173 The message thread tree structure.
6174 (Note that this format doesn't support a field width.)
6176 The number of lines of the message, if available.
6180 The number of octets (bytes) in the message, if available.
6182 Message subject (if any).
6184 Message subject (if any) in double quotes.
6186 Message recipient flags: is the addressee of the message a known or
6187 subscribed mailing list \(en see
6192 The position in threaded/sorted order.
6196 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
6198 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
6209 .It Va headline-bidi
6210 Bidirectional text requires special treatment when displaying headers,
6211 because numbers (in dates or for file sizes etc.) will not affect the
6212 current text direction, in effect resulting in ugly line layouts when
6213 arabic or other right-to-left text is to be displayed.
6214 On the other hand only a minority of terminals is capable to correctly
6215 handle direction changes, so that user interaction is necessary for
6217 Note that extended host system support is required nonetheless, e.g.,
6218 detection of the terminal character set is one precondition;
6219 and this feature only works in an Unicode (i.e., UTF-8) locale.
6221 In general setting this variable will cause \*(UA to encapsulate text
6222 fields that may occur when displaying
6224 (and some other fields, like dynamic expansions in
6226 with special Unicode control sequences;
6227 it is possible to fine-tune the terminal support level by assigning
6229 no value (or any value other than
6234 will make \*(UA assume that the terminal is capable to properly deal
6235 with Unicode version 6.3, in which case text is embedded in a pair of
6236 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6238 In addition no space on the line is reserved for these characters.
6240 Weaker support is chosen by using the value
6242 (Unicode 6.3, but reserve the room of two spaces for writing the control
6243 sequences onto the line).
6248 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6249 again reserves room for two spaces in addition.
6253 \*(OP If a line editor is available then this can be set to
6254 name the (expandable) path of the location of a permanent history file.
6257 .It Va history-gabby
6258 \*(BO\*(OP Add more entries to the history as is normally done.
6261 .It Va history-gabby-persist
6262 \*(BO\*(OP \*(UA's own MLE will not save the additional
6264 entries in persistent storage unless this variable is set.
6265 On the other hand it will not loose the knowledge of wether a persistent
6266 entry was gabby or not.
6272 \*(OP If a line editor is available this value restricts the
6273 amount of history entries that are saved into a set and valid
6275 A value of less than 0 disables this feature;
6276 note that loading and incorporation of
6278 upon program startup can also be suppressed by doing this.
6279 If unset or 0, a default value will be used.
6280 Dependent on the available line editor this will also define the
6281 number of history entries in memory;
6282 it is also editor-specific wether runtime updates of this value will be
6287 \*(BO This option is used to hold messages in the system
6289 box, and it is set by default.
6293 Use this string as hostname when expanding local addresses instead of
6294 the value obtained from
6305 transport is not used then it is normally the responsibility of the MTA
6306 to create these fields, \*(IN in conjunction with
6310 also influences the results;
6311 you should produce some test messages with the desired combination of
6320 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
6321 names according to the rules of IDNA (internationalized domain names
6323 Since the IDNA code assumes that domain names are specified with the
6325 character set, an UTF-8 locale charset is required to represent all
6326 possible international domain names (before conversion, that is).
6330 \*(BO Ignore interrupt signals from the terminal while entering
6331 messages; instead echo them as
6333 characters and discard the current line.
6337 \*(BO Ignore end-of-file conditions
6338 .Pf ( Ql control-D )
6339 in compose mode on message input and in interactive command input.
6340 If set an interactive command input session can only be left by
6341 explicitly using one of the commands
6345 and message input in compose mode can only be terminated by entering
6348 on a line by itself or by using the
6350 .Sx "TILDE ESCAPES" ;
6352 overrides a setting of
6364 option for indenting messages,
6365 in place of the normal tabulator character
6367 which is the default.
6368 Be sure to quote the value if it contains spaces or tabs.
6372 \*(BO If set, an empty mailbox file is not removed.
6373 This may improve the interoperability with other mail user agents
6374 when using a common folder directory, and prevents malicious users
6375 from creating fake mailboxes in a world-writable spool directory.
6376 Note this only applies to local regular (MBOX) files, other mailbox
6377 types will never be removed.
6380 .It Va keep-content-length
6381 \*(BO When (editing messages and) writing
6383 mailbox files \*(UA can be told to keep the
6387 header fields that some MUAs generate by setting this variable.
6388 Since \*(UA does neither use nor update these non-standardized header
6389 fields (which in itself shows one of their conceptual problems),
6390 stripping them should increase interoperability in between MUAs that
6391 work with with same mailbox files.
6392 Note that, if this is not set but
6393 .Va writebackedited ,
6394 as below, is, a possibly performed automatic stripping of these header
6395 fields already marks the message as being modified.
6399 \*(BO When a message is saved it is usually discarded from the
6400 originating folder when \*(UA is quit.
6401 Setting this option causes all saved message to be retained.
6404 .It Va line-editor-disable
6405 \*(BO Turn off any enhanced line editing capabilities (see
6406 .Sx "On terminal control and line editor"
6411 \*(BO When a message is replied to and this variable is set,
6412 it is marked as having been answered.
6413 This mark has no technical meaning in the mail system;
6414 it just causes messages to be marked in the header summary,
6415 and makes them specially addressable.
6419 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6421 Messages which are fetched over the network or from within already
6422 existing Maildir (or any non-MBOX) mailboxes may require so-called
6424 quoting (insertion of additional
6426 characters to prevent line content misinterpretation) to be applied in
6427 order to be storable in MBOX mailboxes, however, dependent on the
6428 circumspection of the message producer.
6429 (E.g., \*(UA itself will, when newly generating messages, choose a
6430 .Pf Content-Transfer- Va encoding
6431 that prevents the necessity for such quoting \(en a necessary
6432 precondition to ensure message checksums won't change.)
6434 By default \*(UA will perform this
6436 quoting in a way that results in a MBOX file that is compatible with
6437 the POSIX MBOX layout, which means that, in order not to exceed the
6438 capabilities of simple applications, many more
6440 lines get quoted (thus modified) than necessary according to RFC 4155.
6441 Set this option to instead generate MBOX files which comply to RFC 4155.
6445 \*(BO Internal development variable.
6448 .It Va message-id-disable
6449 \*(BO By setting this option the generation of
6451 can be completely suppressed, effectively leaving this task up to the
6452 mail-transfer-agent (MTA) or the SMTP server.
6453 (According to RFC 5321 your SMTP server is not required to add this
6454 field by itself, so you should ensure that it accepts messages without a
6458 .It Va message-inject-head
6459 A string to put at the beginning of each new message.
6460 The escape sequences tabulator
6467 .It Va message-inject-tail
6468 A string to put at the end of each new message.
6469 The escape sequences tabulator
6477 \*(BO Usually, when an
6479 expansion contains the sender, the sender is removed from the expansion.
6480 Setting this option suppresses these removals.
6485 option to be passed to mail-transfer-agents (MTAs);
6486 though most of the modern MTAs don't (no longer) document this flag, no
6487 MTA is known which doesn't support it (for historical compatibility).
6490 .It Va mime-allow-text-controls
6491 \*(BO When sending messages, each part of the message is MIME-inspected
6492 in order to classify the
6495 .Ql Content-Transfer-Encoding:
6498 that is required to send this part over mail transport, i.e.,
6499 a computation rather similar to what the
6501 command produces when used with the
6505 This classification however treats text files which are encoded in
6506 UTF-16 (seen for HTML files) and similar character sets as binary
6507 octet-streams, forcefully changing any
6512 .Ql application/octet-stream :
6513 If that actually happens a yet unset charset MIME parameter is set to
6515 effectively making it impossible for the receiving MUA to automatically
6516 interpret the contents of the part.
6518 If this option is set, and the data was unambiguously identified as text
6519 data at first glance (by a
6523 file extension), then the original
6525 will not be overwritten.
6528 .It Va mime-alternative-favour-rich
6529 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6530 HTML) will be preferred in favour of included plain text versions when
6531 displaying messages, provided that a handler exists which produces
6532 output that can be (re)integrated into \*(UA's normal visual display.
6533 (E.g., at the time of this writing some newsletters ship their full
6534 content only in the rich HTML part, whereas the plain text part only
6535 contains topic subjects.)
6538 .It Va mime-counter-evidence
6541 field is used to decide how to handle MIME parts.
6542 Some MUAs however don't use
6544 or a similar mechanism to correctly classify content, but simply specify
6545 .Ql application/octet-stream ,
6546 even for plain text attachments like
6548 If this variable is set then \*(UA will try to classify such MIME
6549 message parts on its own, if possible, for example via a possibly
6550 existent attachment filename.
6551 A non-empty value may also be given, in which case a number is expected,
6552 actually a carrier of bits.
6553 Creating the bit-carrying number is a simple addition:
6554 .Bd -literal -offset indent
6555 ? !echo Value should be set to $((2 + 4 + 8))
6556 Value should be set to 14
6559 .Bl -bullet -compact
6561 If bit two is set (2) then the detected
6563 content-type will be carried along with the message and be used for
6565 .Va pipe-TYPE/SUBTYPE
6566 is responsible for the MIME part, shall that question arise;
6567 when displaying such a MIME part the part-info will indicate the
6568 overridden content-type by showing a plus-sign
6571 If bit three is set (4) then the counter-evidence is always produced
6572 and a positive result will be used as the MIME type, even forcefully
6573 overriding the parts given MIME type.
6575 If bit four is set (8) then as a last resort the actual content of
6576 .Ql application/octet-stream
6577 parts will be inspected, so that data which looks like plain text can be
6582 .It Va mimetypes-load-control
6583 This option can be used to control which of the
6585 databases are loaded by \*(UA, as furtherly described in the section
6586 .Sx "The mime.types files" .
6589 is part of the option value, then the user's personal
6591 file will be loaded (if it exists); likewise the letter
6593 controls loading of the system wide
6594 .Pa /etc/mime.types ;
6595 directives found in the user file take precedence, letter matching is
6597 If this option is not set \*(UA will try to load both files.
6598 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6599 but they will be matched last.
6601 More sources can be specified by using a different syntax: if the
6602 value string contains an equals sign
6604 then it is instead parsed as a comma-separated list of the described
6607 pairs; the given filenames will be expanded and loaded, and their
6608 content may use the extended syntax that is described in the section
6609 .Sx "The mime.types files" .
6610 Directives found in such files always take precedence (are prepended to
6611 the MIME type cache).
6614 .It Va NAIL_EXTRA_RC
6615 The name of an optional startup file to be read last.
6616 This variable has an effect only if it is set in any of the
6617 .Sx "Resource files" ,
6618 it is not imported from the environment.
6619 Use this file for commands that are not understood by other POSIX
6624 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6625 \*(BO\*(IN\*(OP Used to control usage of the users
6627 file for lookup of account credentials, as documented in the section
6628 .Sx "On URL syntax and credential lookup"
6632 .Sx "The .netrc file"
6633 documents the file format.
6637 If this variable has the value
6639 newly created local folders will be in Maildir format.
6643 Checks for new mail in the current folder each time the prompt is shown.
6644 A Maildir folder must be re-scanned to determine if new mail has arrived.
6645 If this variable is set to the special value
6647 then a Maildir folder will not be rescanned completely, but only
6648 timestamp changes are detected.
6652 .It Va on-compose-enter , on-compose-leave
6653 \*(ID Macro hooks which will be executed before compose mode is
6654 entered, and after composing has been finished, respectively.
6655 Please note that this interface is very likely to change in v15, and
6656 should therefore possibly even be seen as experimental.
6658 are by default enabled for these hooks, causing any setting to be
6659 forgotten after the message has been sent.
6660 The following variables will be set temporarily during execution of the
6663 .Bl -tag -compact -width ".It Va compose_subject"
6666 .It Va compose-sender
6668 .It Va compose-to , compose-cc , compose-bcc
6669 The list of receiver addresses as a space-separated list.
6670 .It Va compose-subject
6676 \*(BO Causes the filename given in the
6679 and the sender-based filenames for the
6683 commands to be interpreted relative to the directory given in the
6685 variable rather than to the current directory,
6686 unless it is set to an absolute pathname.
6690 \*(BO If set, each message feed through the command given for
6692 is followed by a formfeed character
6696 .It Va password-USER@HOST , password-HOST , password
6697 \*(IN Variable chain that sets a password, which is used in case none has
6698 been given in the protocol and account-specific URL;
6699 as a last resort \*(UA will ask for a password on the user's terminal if
6700 the authentication method requires a password.
6701 Specifying passwords in a startup file is generally a security risk;
6702 the file should be readable by the invoking user only.
6704 .It Va password-USER@HOST
6705 \*(OU (see the chain above for \*(IN)
6706 Set the password for
6710 If no such variable is defined for a host,
6711 the user will be asked for a password on standard input.
6712 Specifying passwords in a startup file is generally a security risk;
6713 the file should be readable by the invoking user only.
6717 \*(BO Send messages to the
6719 command without performing MIME and character set conversions.
6723 .It Va pipe-TYPE/SUBTYPE
6724 When a MIME message part of type
6726 (case-insensitive) is displayed or quoted,
6727 its text is filtered through the value of this variable interpreted as
6731 forces interpretation of the message part as plain text, e.g.,
6732 .Ql set pipe-application/xml=@
6733 will henceforth display XML
6735 (The same could also be achieved by adding a MIME type marker with the
6738 And \*(OPally MIME type handlers may be defined via
6739 .Sx "The Mailcap files"
6740 \(em corresponding flag strings are shown in parenthesis below.)
6745 can in fact be used to adjust usage and behaviour of a following shell
6746 command specification by appending trigger characters to it, e.g., the
6747 following hypothetical command specification could be used:
6748 .Bd -literal -offset indent
6749 set pipe-X/Y='@*!++=@vim ${NAIL_FILENAME_TEMPORARY}'
6753 .Bl -tag -compact -width ".It Ql __"
6755 Simply by using the special
6757 prefix the MIME type (shell command) handler will only be invoked to
6758 display or convert the MIME part if the message is addressed directly
6759 and alone by itself.
6760 Use this trigger to disable this and always invoke the handler
6761 .Pf ( Cd x-mailx-always ) .
6764 If set the handler will not be invoked when a message is to be quoted,
6765 but only when it will be displayed
6766 .Pf ( Cd x-mailx-noquote ) .
6769 The command will be run asynchronously, i.e., without blocking \*(UA,
6770 which may be a handy way to display a, e.g., PDF file while also
6771 continuing to read the mail message
6772 .Pf ( Cd x-mailx-async ) .
6773 Asynchronous execution implies
6777 The command must be run on an interactive terminal, \*(UA will
6778 temporarily release the terminal to it
6779 .Pf ( Cd needsterminal ) .
6780 This flag is mutual exclusive with
6782 will only be used in interactive mode and implies
6786 Request creation of a zero-sized temporary file, the absolute pathname
6787 of which will be made accessable via the environment variable
6788 .Ev NAIL_FILENAME_TEMPORARY
6789 .Pf ( Cd x-mailx-tmpfile ) .
6790 If this trigger is given twice then the file will be unlinked
6791 automatically by \*(UA when the command loop is entered again at latest
6792 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6793 (Don't use this for asynchronous handlers.)
6796 Normally the MIME part content is passed to the handler via standard
6797 input; if this flag is set then the data will instead be written into
6798 .Ev NAIL_FILENAME_TEMPORARY
6799 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6800 the creation of which is implied; note however that in order to cause
6801 deletion of the temporary file you still have to use two plus signs
6806 To avoid ambiguities with normal shell command content you can use
6807 another at-sign to forcefully terminate interpretation of remaining
6809 (Any character not in this list will have the same effect.)
6813 Some information about the MIME part to be displayed is embedded into
6814 the environment of the shell command:
6817 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6820 The MIME content-type of the part, if known, the empty string otherwise.
6823 .It Ev NAIL_CONTENT_EVIDENCE
6825 .Va mime-counter-evidence
6826 includes the carry-around-bit (2), then this will be set to the detected
6827 MIME content-type; not only then identical to
6828 .Ev \&\&NAIL_CONTENT
6832 .It Ev NAIL_FILENAME
6833 The filename, if any is set, the empty string otherwise.
6836 .It Ev NAIL_FILENAME_GENERATED
6840 .It Ev NAIL_FILENAME_TEMPORARY
6841 If temporary file creation has been requested through the command prefix
6842 this variable will be set and contain the absolute pathname of the
6847 The temporary directory that \*(UA uses.
6848 Usually identical to
6850 but guaranteed to be set and usable by child processes;
6851 to ensure the latter condition for
6858 .It Va pipe-EXTENSION
6859 This is identical to
6860 .Va pipe-TYPE/SUBTYPE
6863 (normalized to lowercase using character mappings of the ASCII charset)
6864 names a file extension, e.g.,
6866 Handlers registered using this method take precedence.
6869 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6870 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6871 The only possible value as of now is
6873 which is thus the default.
6876 .Mx Va pop3-bulk-load
6877 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6878 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6879 the messages, and only requests the message bodies on user request.
6880 For the POP3 protocol this means that the message headers will be
6882 If this option is set then \*(UA will download only complete messages
6883 from the given POP3 server(s) instead.
6885 .Mx Va pop3-keepalive
6886 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6887 \*(OP POP3 servers close the connection after a period of inactivity;
6888 the standard requires this to be at least 10 minutes,
6889 but practical experience may vary.
6890 Setting this variable to a numeric value greater than
6894 command to be sent each value seconds if no other operation is performed.
6897 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6898 \*(BO\*(OP Unless this variable is set the
6900 authentication method will be used when connecting to a POP3 server that
6904 is that the password is not sent in clear text over the wire and that
6905 only a single packet is sent for the user/password tuple.
6907 .Va pop3-no-apop-HOST
6910 .Mx Va pop3-use-starttls
6911 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6912 \*(BO\*(OP Causes \*(UA to issue a
6914 command to make an unencrypted POP3 session SSL/TLS encrypted.
6915 This functionality is not supported by all servers,
6916 and is not used if the session is already encrypted by the POP3S method.
6918 .Va pop3-use-starttls-HOST
6922 .It Va print-alternatives
6923 \*(BO When a MIME message part of type
6924 .Ql multipart/alternative
6925 is displayed and it contains a subpart of type
6927 other parts are normally discarded.
6928 Setting this variable causes all subparts to be displayed,
6929 just as if the surrounding part was of type
6930 .Ql multipart/mixed .
6934 The string shown when a command is accepted.
6935 Prompting may be prevented by setting this to the null string
6937 .Pf no Va prompt ) .
6938 If a value is assigned the following \*(UA specific additional sequences
6945 is set, in which case it expands to
6949 is the default value of
6952 which will expand to
6954 if the last command failed and to
6958 which will expand to the name of the currently active
6960 if any, and to the empty string otherwise, and
6962 which will expand to the name of the currently active mailbox.
6963 (Note that the prompt buffer is size-limited, excess is cut off.)
6969 to encapsulate the expansions of the
6973 escape sequences as necessary to correctly display bidirectional text,
6974 this is not true for the final string that makes up
6976 as such, i.e., real BIDI handling is not supported.
6980 \*(BO Suppresses the printing of the version when first invoked.
6984 If set, \*(UA starts a replying message with the original message
6985 prefixed by the value of the variable
6987 Normally, a heading consisting of
6988 .Dq Fromheaderfield wrote:
6989 is put before the quotation.
6994 variable, this heading is omitted.
6997 is assigned, the headers selected by the
6998 .Ic ignore Ns / Ns Ic retain
6999 commands are put above the message body,
7002 acts like an automatic
7008 is assigned, all headers are put above the message body and all MIME
7009 parts are included, making
7011 act like an automatic
7014 .Va quote-as-attachment .
7017 .It Va quote-as-attachment
7018 \*(BO Add the original message in its entirety as a
7020 MIME attachment when replying to a message.
7021 Note this works regardless of the setting of
7026 \*(OP Can be set in addition to
7028 Setting this turns on a more fancy quotation algorithm in that leading
7029 quotation characters are compressed and overlong lines are folded.
7031 can be set to either one or two (space separated) numeric values,
7032 which are interpreted as the maximum (goal) and the minimum line length,
7033 respectively, in a spirit rather equal to the
7035 program, but line-, not paragraph-based.
7036 If not set explicitly the minimum will reflect the goal algorithmically.
7037 The goal can't be smaller than the length of
7039 plus some additional pad.
7040 Necessary adjustments take place silently.
7043 .It Va recipients-in-cc
7044 \*(BO On group replies, specify only the sender of the original mail in
7046 and mention the other recipients in the secondary
7048 By default all recipients of the original mail will be addressed via
7053 If defined, gives the pathname of the folder used to record all outgoing
7055 If not defined, then outgoing mail is not saved.
7056 When saving to this folder fails the message is not sent,
7057 but instead saved to
7061 .It Va record-resent
7062 \*(BO If both this variable and the
7069 commands save messages to the
7071 folder as it is normally only done for newly composed messages.
7074 .It Va reply-in-same-charset
7075 \*(BO If this variable is set \*(UA first tries to use the same
7076 character set of the original message for replies.
7077 If this fails, the mechanism described in
7078 .Sx "Character sets"
7079 is evaluated as usual.
7082 .It Va reply_strings
7083 Can be set to a comma-separated list of (case-insensitive according to
7084 ASCII rules) strings which shall be recognized in addition to the
7087 reply message indicators \(en builtin are
7089 which is mandated by RFC 5322, as well as the german
7094 A list of addresses to put into the
7096 field of the message header.
7097 Members of this list are handled as if they were in the
7102 .It Va reply-to-honour
7105 header is honoured when replying to a message via
7109 This is a quadoption; if set without a value it defaults to
7113 .It Va rfc822-body-from_
7114 \*(BO This variable can be used to force displaying a so-called
7116 line for messages that are embedded into an envelope mail via the
7118 MIME mechanism, for more visual convenience.
7122 \*(BO Enable saving of (partial) messages in
7124 upon interrupt or delivery error.
7128 When \*(UA initially displays the message headers it determines the
7129 number to display by looking at the speed of the terminal.
7130 The faster the terminal, the more will be shown.
7131 This option specifies the number to use and overrides the calculation.
7132 This number is also used for scrolling with the
7135 Overall screen dimensions and pager usage is influenced by the
7136 environment variables
7144 .It Va searchheaders
7145 \*(BO Expand message-list specifiers in the form
7147 to all messages containing the substring
7151 The string search is case insensitive.
7155 \*(OP A comma-separated list of character set names that can be used in
7156 outgoing internet mail.
7157 The value of the variable
7159 is automatically appended to this list of character-sets.
7160 If no character set conversion capabilities are compiled into \*(UA then
7161 the only supported charset is
7164 .Va sendcharsets-else-ttycharset
7165 and refer to the section
7166 .Sx "Character sets"
7167 for the complete picture of character set conversion in \*(UA.
7170 .It Va sendcharsets-else-ttycharset
7171 \*(BO\*(OP If this variable is set, but
7173 is not, then \*(UA acts as if
7175 had been set to the value of the variable
7177 In effect this combination passes through the message data in the
7178 character set of the current locale (given that
7180 hasn't been set manually), i.e., without converting it to the
7182 fallback character set.
7183 Thus, mail message text will be in ISO-8859-1 encoding when send from
7184 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
7186 If no character set conversion capabilities are available in \*(UA then
7187 the only supported character set is
7192 An address that is put into the
7194 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
7195 responsible for the actual transmission of the message.
7196 This field should normally not be used unless the
7198 field contains more than one address, on which case it is required.
7201 address is handled as if it were in the
7207 To use an alternate mail transport agent (MTA),
7208 set this option to the full pathname of the program to use.
7209 It may be necessary to set
7210 .Va sendmail-progname
7213 The MTA will be passed command line arguments from several possible
7214 sources: from the variable
7215 .Va sendmail-arguments
7216 if set, from the command line if given and the variable
7219 Argument processing of the MTA will be terminated with a
7223 The otherwise occurring implicit usage of the following MTA command line
7224 arguments can be disabled by setting the boolean option
7225 .Va sendmail-no-default-arguments
7226 (which will also disable passing
7230 (for not treating a line with only a dot
7232 character as the end of input),
7240 option is set); in conjunction with the
7242 command line option \*(UA will also pass
7248 .It Va sendmail-arguments
7249 Arguments to pass through to the Mail-Transfer-Agent can be given via
7251 The content of this variable will be split up in a vector of arguments
7252 which will be joined onto other possible MTA options:
7254 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7257 .It Va sendmail-no-default-arguments
7258 \*(BO Unless this option is set \*(UA will pass some well known
7259 standard command line options to the defined
7261 program, see there for more.
7264 .It Va sendmail-progname
7265 Many systems use a so-called
7267 environment to ensure compatibility with
7269 This works by inspecting the name that was used to invoke the mail
7271 If this variable is set then the mailwrapper (the program that is
7272 actually executed when calling
7274 will treat its contents as that name.
7280 \*(BO When sending a message wait until the MTA (including the builtin
7281 SMTP one) exits before accepting further commands.
7283 with this variable set errors reported by the MTA will be recognizable!
7284 If the MTA returns a non-zero exit status,
7285 the exit status of \*(UA will also be non-zero.
7289 \*(BO Setting this option causes \*(UA to start at the last message
7290 instead of the first one when opening a mail folder.
7294 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7295 address in the header field summary and in message specifications.
7299 \*(BO Causes the recipient of the message to be shown in the header
7300 summary if the message was sent by the user.
7304 A string for use with the
7310 A string for use with the
7316 Must correspond to the name of a readable file if set.
7317 The file's content is then appended to each singlepart message
7318 and to the first part of each multipart message.
7319 Be warned that there is no possibility to edit the signature for an
7323 .It Va skipemptybody
7324 \*(BO If an outgoing message does not contain any text in its first or
7325 only message part, do not send it but discard it silently (see also the
7331 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7332 Enhanced Mail) format for verification of S/MIME signed messages.
7335 .It Va smime-ca-file
7336 \*(OP Specifies a file with CA certificates in PEM format for
7337 verification of S/MIME signed messages.
7340 .It Va smime-cipher-USER@HOST , smime-cipher
7341 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7342 messages (for the specified account).
7343 RFC 5751 mandates a default of
7346 Possible values are (case-insensitive and) in decreasing cipher strength:
7354 (DES EDE3 CBC, 168 bits; default if
7356 isn't available) and
7360 The actually available cipher algorithms depend on the cryptographic
7361 library that \*(UA uses.
7362 \*(OP Support for more cipher algorithms may be available through
7363 dynamic loading via, e.g.,
7364 .Xr EVP_get_cipherbyname 3
7365 (OpenSSL) if \*(UA has been compiled to support this.
7368 .It Va smime-crl-dir
7369 \*(OP Specifies a directory that contains files with CRLs in PEM format
7370 to use when verifying S/MIME messages.
7373 .It Va smime-crl-file
7374 \*(OP Specifies a file that contains a CRL in PEM format to use when
7375 verifying S/MIME messages.
7378 .It Va smime-encrypt-USER@HOST
7379 \*(OP If this variable is set, messages send to the given receiver are
7380 encrypted before sending.
7381 The value of the variable must be set to the name of a file that
7382 contains a certificate in PEM format.
7384 If a message is sent to multiple recipients,
7385 each of them for whom a corresponding variable is set will receive an
7386 individually encrypted message;
7387 other recipients will continue to receive the message in plain text
7389 .Va smime-force-encryption
7391 It is recommended to sign encrypted messages, i.e., to also set the
7396 .It Va smime-force-encryption
7397 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7400 .It Va smime-no-default-ca
7401 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7406 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7407 and include the user's certificate as a MIME attachment.
7408 Signing a message enables a recipient to verify that the sender used
7409 a valid certificate,
7410 that the email addresses in the certificate match those in the message
7411 header and that the message content has not been altered.
7412 It does not change the message text,
7413 and people will be able to read the message as usual.
7415 .Va smime-sign-cert , smime-sign-include-certs
7417 .Va smime-sign-message-digest .
7419 .Mx Va smime-sign-cert
7420 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7421 \*(OP Points to a file in PEM format.
7422 For the purpose of signing and decryption this file needs to contain the
7423 user's private key as well as his certificate.
7427 is always derived from the value of
7429 (or, if that contains multiple addresses,
7431 For the purpose of encryption the recipient's public encryption key
7432 (certificate) is expected; the command
7434 can be used to save certificates of signed messages (the section
7435 .Sx "Signed and encrypted messages with S/MIME"
7436 gives some details).
7437 This mode of operation is usually driven by the specialized form.
7439 When decrypting messages the account is derived from the recipient
7444 of the message, which are searched for addresses for which such
7446 \*(UA always uses the first address that matches,
7447 so if the same message is sent to more than one of the user's addresses
7448 using different encryption keys, decryption might fail.
7450 .Mx Va smime-sign-include-certs
7451 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7452 \*(OP If used, this is supposed to a consist of a comma-separated list
7453 of files, each of which containing a single certificate in PEM format to
7454 be included in the S/MIME message in addition to the
7457 This is most useful for long certificate chains if it is desired to aid
7458 the receiving party's verification process.
7459 Note that top level certificates may also be included in the chain but
7460 don't play a role for verification.
7462 .Va smime-sign-cert .
7463 Remember that for this
7465 refers to the variable
7467 (or, if that contains multiple addresses,
7470 .Mx Va smime-sign-message-digest
7471 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7472 \*(OP Specifies the message digest to use when signing S/MIME messages.
7473 RFC 5751 mandates a default of
7475 Possible values are (case-insensitive and) in decreasing cipher strength:
7483 The actually available message digest algorithms depend on the
7484 cryptographic library that \*(UA uses.
7485 \*(OP Support for more message digest algorithms may be available
7486 through dynamic loading via, e.g.,
7487 .Xr EVP_get_digestbyname 3
7488 (OpenSSL) if \*(UA has been compiled to support this.
7489 Remember that for this
7491 refers to the variable
7493 (or, if that contains multiple addresses,
7499 \*(OP Normally \*(UA invokes the program defined via
7501 to transfer messages, as described in
7502 .Sx "On sending mail, and non-interactive mode" .
7505 variable will instead cause SMTP network connections be made to the
7506 server specified therein in order to directly submit the message.
7507 \*(UA knows about three different
7508 .Dq SMTP protocols :
7510 .Bl -bullet -compact
7512 The plain SMTP protocol (RFC 5321) that normally lives on the
7513 server port 25 and requires setting the
7514 .Va smtp-use-starttls
7515 variable to enter a SSL/TLS encrypted session state.
7516 Assign a value like \*(IN
7517 .Ql [smtp://][user[:password]@]server[:port]
7519 .Ql [smtp://]server[:port] )
7520 to choose this protocol.
7522 Then the so-called SMTPS which is supposed to live on server port 465
7523 and is automatically SSL/TLS secured.
7524 Unfortunately it never became a standardized protocol and may thus not
7525 be supported by your hosts network service database
7526 \(en in fact the port number has already been reassigned to other
7529 SMTPS is nonetheless a commonly offered protocol and thus can be
7530 chosen by assigning a value like \*(IN
7531 .Ql smtps://[user[:password]@]server[:port]
7533 .Ql smtps://server[:port] ) ;
7534 due to the mentioned problems it is usually necessary to explicitly
7539 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7540 lives on server port 587 and is practically identically to the SMTP
7541 protocol from \*(UA's point of view beside that; it requires setting the
7542 .Va smtp-use-starttls
7543 variable to enter a SSL/TLS secured session state.
7544 Assign a value like \*(IN
7545 .Ql submission://[user[:password]@]server[:port]
7547 .Ql submission://server[:port] ) .
7550 For more on credentials etc. please see
7551 .Sx "On URL syntax and credential lookup" .
7552 The SMTP transfer is executed in a child process, which runs
7553 asynchronously unless either the
7558 If it receives a TERM signal, it will abort and save the message to
7563 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7564 \*(OP Variable chain that sets the SMTP authentication method.
7571 as well as the \*(OPal methods
7577 method doesn't need any user credentials,
7579 requires a user name and all other methods require a user name and
7587 .Va smtp-auth-password
7589 .Va smtp-auth-user ) .
7594 .Va smtp-auth-USER@HOST :
7595 may override dependend on sender address in the variable
7598 .It Va smtp-auth-password
7599 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7600 If the authentication method requires a password, but neither
7601 .Va smtp-auth-password
7603 .Va smtp-auth-password-USER@HOST
7605 \*(UA will ask for a password on the user's terminal.
7607 .It Va smtp-auth-password-USER@HOST
7609 .Va smtp-auth-password
7610 for specific values of sender addresses, dependent upon the variable
7613 .It Va smtp-auth-user
7614 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7615 If the authentication method requires a user name, but neither
7618 .Va smtp-auth-user-USER@HOST
7620 \*(UA will ask for a user name on the user's terminal.
7622 .It Va smtp-auth-user-USER@HOST
7625 for specific values of sender addresses, dependent upon the variable
7629 .It Va smtp-hostname
7630 \*(IN Normally \*(UA uses the variable
7632 to derive the necessary
7634 information to issue a
7639 can be used to use the
7641 from the SMTP account
7648 from the content of this variable (or, if that is the empty string,
7650 or the local hostname as a last resort).
7651 This often allows using an address that is itself valid but hosted by
7652 a provider other than which (in
7654 is about to send the message.
7655 Setting this variable also influences the generated
7658 .Mx Va smtp-use-starttls
7659 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7660 \*(BO\*(OP Causes \*(UA to issue a
7662 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7663 transport layer security.
7667 .It Va spam-interface
7668 \*(OP In order to use any of the spam-related commands (like, e.g.,
7670 the desired spam interface must be defined by setting this variable.
7671 Please refer to the manual section
7673 for the complete picture of spam handling in \*(UA.
7674 All or none of the following interfaces may be available:
7676 .Bl -tag -width ".It Ql _ilte_"
7682 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7684 Different to the generic filter interface \*(UA will automatically add
7685 the correct arguments for a given command and has the necessary
7686 knowledge to parse the program's output.
7689 will have been compiled into the \*(UA binary if
7694 Shall it be necessary to define a specific connection type (rather than
7695 using a configuration file for that), the variable
7697 can be used as in, e.g.,
7698 .Ql -d server.example.com -p 783 .
7699 It is also possible to specify a per-user configuration via
7701 Note that this interface doesn't inspect the
7703 flag of a message for the command
7707 \*(UA will directly communicate with the
7713 stream socket as specified in
7715 It is possible to specify a per-user configuration via
7719 generic spam filter support via freely configurable hooks.
7720 This interface is ment for programs like
7724 and requires according behaviour in respect to the hooks' exit
7725 status for at least the command
7728 meaning a message is spam,
7732 for unsure and any other return value indicating a hard error);
7733 since the hooks can include shell code snippets diverting behaviour
7734 can be intercepted as necessary.
7736 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7739 .Va spamfilter-spam ;
7742 contains examples for some programs.
7743 The process environment of the hooks will have the variables
7744 .Ev NAIL_TMPDIR , TMPDIR
7746 .Ev NAIL_FILENAME_GENERATED
7748 Note that spam score support for
7750 isn't supported unless the \*(OPtional regular expression support is
7752 .Va spamfilter-rate-scanscore
7759 \*(OP Messages that exceed this size won't be passed through to the
7761 .Va spam-interface .
7762 If unset or 0, the default of 420000 bytes is used.
7765 .It Va spamc-command
7766 \*(OP The path to the
7770 .Va spam-interface .
7771 Note that the path is not expanded, but used
7773 A fallback path will have been compiled into the \*(UA binary if the
7774 executable had been found during compilation.
7777 .It Va spamc-arguments
7778 \*(OP Even though \*(UA deals with most arguments for the
7781 automatically, it may at least sometimes be desirable to specifiy
7782 connection-related ones via this variable, e.g.,
7783 .Ql -d server.example.com -p 783 .
7787 \*(OP Specify a username for per-user configuration files for the
7789 .Va spam-interface .
7790 If this is set to the empty string then \*(UA will use the name of the
7796 \*(OP Specify the path of the
7798 domain socket on which
7800 listens for connections for the
7802 .Va spam-interface .
7803 Note that the path is not expanded, but used
7808 \*(OP Specify a username for per-user configuration files for the
7810 .Va spam-interface .
7811 If this is set to the empty string then \*(UA will use the name of the
7820 .It Va spamfilter-ham , spamfilter-noham , \
7821 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7822 \*(OP Command and argument hooks for the
7824 .Va spam-interface .
7827 contains examples for some programs.
7830 .It Va spamfilter-rate-scanscore
7831 \*(OP Because of the generic nature of the
7834 spam scores are not supported for it by default, but if the \*(OPtional
7835 regular expression support is available then setting this variable can
7836 be used to overcome this restriction.
7837 It is interpreted as follows: first a number (digits) is parsed that
7838 must be followed by a semicolon
7840 and an extended regular expression.
7841 Then the latter is used to parse the first output line of the
7843 hook, and, in case the evaluation is successful, the group that has been
7844 specified via the number is interpreted as a floating point scan score.
7848 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7849 Enhanced Mail) for verification of of SSL/TLS server certificates.
7851 .Xr SSL_CTX_load_verify_locations 3
7852 for more information.
7856 \*(OP Specifies a file with CA certificates in PEM format for
7857 verification of SSL/TLS server certificates.
7859 .Xr SSL_CTX_load_verify_locations 3
7860 for more information.
7863 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7864 \*(OP Variable chain that sets the file name for a SSL/TLS client
7865 certificate required by some servers.
7866 This is a direct interface to the
7870 function of the OpenSSL library, if available.
7872 .Mx Va ssl-cipher-list
7873 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7874 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7875 This is a direct interface to the
7879 function of the OpenSSL library, if available; see
7881 for more information.
7882 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7884 specific cipher (protocol standards ship with a list of acceptable
7885 ciphers), possibly cramped to what the actually used SSL/TLS library
7886 supports \(en the manual section
7887 .Sx "An example configuration"
7888 also contains a SSL/TLS use case.
7891 .It Va ssl-config-file
7892 \*(OP If this variable is set \*(UA will call
7893 .Xr CONF_modules_load_file 3
7894 to allow OpenSSL to be configured according to the host system wide
7896 If a non-empty value is given then this will be used to specify the
7897 configuration file to be used instead of the global OpenSSL default;
7898 note that in this case it is an error if the file cannot be loaded.
7899 The application name will always be passed as
7904 \*(OP Specifies a file that contains a CRL in PEM format to use when
7905 verifying SSL/TLS server certificates.
7909 \*(OP Specifies a directory that contains files with CRLs in PEM format
7910 to use when verifying SSL/TLS server certificates.
7913 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7914 \*(OP Variable chain that sets the file name for the private key of
7915 a SSL/TLS client certificate.
7916 If unset, the name of the certificate file is used.
7917 The file is expected to be in PEM format.
7918 This is a direct interface to the
7922 function of the OpenSSL library, if available.
7925 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7927 \*(OB Please use the newer and more flexible
7929 instead: if both values are set,
7931 will take precedence!
7932 Can be set to the following values, the actually used
7934 specification to which it is mapped is shown in parenthesis:
7936 .Pf ( Ql -ALL, TLSv1.2 ) ,
7938 .Pf ( Ql -ALL, TLSv1.1 ) ,
7940 .Pf ( Ql -ALL, TLSv1 )
7943 .Pf ( Ql -ALL, SSLv3 ) ;
7948 and thus includes the SSLv3 protocol.
7949 Note that SSLv2 is no longer supported at all.
7952 .It Va ssl-no-default-ca
7953 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7957 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7958 \*(OP Specify the used SSL/TLS protocol.
7959 This is a direct interface to the
7963 function of the OpenSSL library, if available;
7964 otherwise an \*(UA internal parser is used which understands the
7965 following subset of (case-insensitive) command strings:
7971 as well as the special value
7973 Multiple specifications may be given via a comma-separated list which
7974 ignores any whitespace.
7977 plus prefix will enable a protocol, a
7979 minus prefix will disable it, so that
7981 will enable only the TLSv1.2 protocol.
7983 It depends upon the used TLS/SSL library which protocols are actually
7984 supported and which protocols are used if
7986 is not set, but note that SSLv2 is no longer supported at all and
7988 Especially for older protocols explicitly securing
7990 may be worthwile, see
7991 .Sx "An example configuration" .
7995 \*(OP Gives the pathname to an entropy daemon socket, see
7997 Not all SSL/TLS libraries support this.
8000 .It Va ssl-rand-file
8001 \*(OP Gives the filename to a file with random entropy data, see
8002 .Xr RAND_load_file 3 .
8003 If this variable is not set, or set to the empty string, or if the
8004 filename expansion failed, then
8005 .Xr RAND_file_name 3
8006 will be used to create the filename if, and only if,
8008 documents that the SSL PRNG is not yet sufficiently seeded.
8009 If \*(UA successfully seeded the SSL PRNG then it'll update the file via
8010 .Xr RAND_write_file 3 .
8011 This variable is only used if
8013 is not set (or not supported by the SSL/TLS library).
8016 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
8017 \*(OP Variable chain that sets the action to be performed if an error
8018 occurs during SSL/TLS server certificate validation.
8019 Valid (case-insensitive) values are
8021 (fail and close connection immediately),
8023 (ask whether to continue on standard input),
8025 (show a warning and continue),
8027 (do not perform validation).
8033 If only set without an assigned value, then this option inhibits the
8038 header fields that include obvious references to \*(UA.
8039 There are two pitfalls associated with this:
8040 First, the message id of outgoing messages is not known anymore.
8041 Second, an expert may still use the remaining information in the header
8042 to track down the originating mail user agent.
8047 suppression doesn't occur.
8052 (\*(OP) This specifies a comma-separated list of
8057 .Sx "On terminal control and line editor" ,
8058 escape commas with backslash) to be used to overwrite or define entries.
8060 that this variable will only be queried once at program startup and can
8061 thus only be specified in resource files or on the command line.
8064 String capabilities form
8066 pairs and are expected unless noted otherwise.
8067 Numerics have to be notated as
8069 where the number is expected in normal decimal notation.
8070 Finally, booleans don't have any value but indicate a true or false
8071 state simply by being defined or not; this indeed means that \*(UA
8072 doesn't support undefining a boolean that normally exists.
8073 The following example defines that the terminal has 256 colours:
8075 .Bd -literal -offset indent
8076 set termcap="colors=256"
8080 Keycodes can easily be detected with the command
8082 by running it on an interactive terminal via
8086 command line option if available) and pressing some keys: here
8094 (actually a visualized numeric where
8096 stands for 1 etc.; in fact: the numeric value of
8098 in the US-ASCII character set bitwise XORd with
8101 .Ql $ echo $((0x41 ^ 0x40)) .
8104 and other control characters have to be notated as shell-style
8105 escape sequences, e.g.,
8115 The following terminal capabilities are or may be meaningful for the
8116 operation of the builtin line editor or \*(UA in general:
8119 .Bl -tag -compact -width yay
8121 .It Cd colors Ns \0or Cd Co
8123 numeric capability specifying the maximum number of colours.
8124 Note that \*(UA doesn't actually care about the terminal beside that,
8125 but always emits ANSI/ISO 6429 escape sequences for producing the
8126 colour and font attributes.
8129 .It Cd rmcup Ns \0or Cd te Ns \0/ Cd smcup Ns \0or Cd ti
8133 respectively: exit and enter the alternative screen
8135 effectively turning \*(UA into a fullscreen application.
8136 To disable that, set (at least) one to the empty string.
8138 .It Cd smkx Ns \0or Cd ks Ns \0/ Cd rmkx Ns \0or Cd ke
8142 respectively: enable and disable the keypad.
8143 This is always enabled if available, because it seems even keyboards
8144 without keypads generate other key codes for, e.g., cursor keys in that
8145 case, and only if enabled we see the codes that we are interested in.
8147 .It Cd ed Ns \0or Cd cd
8151 .It Cd clear Ns \0or Cd cl
8153 clear the screen and home cursor.
8154 (Will be simulated via
8159 .It Cd home Ns \0or Cd ho
8164 .It Cd el Ns \0or Cd ce
8166 clear to the end of line.
8167 (Will be simulated via
8169 plus repititions of space characters.)
8171 .It Cd hpa Ns \0or Cd ch
8172 .Cd column_address :
8173 move the cursor (to the given column parameter) in the current row.
8174 (Will be simulated via
8180 .Cd carriage_return :
8181 move to the first column in the current row.
8182 The default builtin fallback is
8185 .It Cd cub1 Ns \0or Cd le
8187 move the cursor left one space (non-destructively).
8188 The default builtin fallback is
8191 .It Cd cuf1 Ns \0or Cd nd
8193 move the cursor right one space (non-destructively).
8194 The default builtin fallback is
8196 which is used by most terminals.
8205 .It Va termcap-disable
8206 \*(OP Disable any interaction with a terminal control library.
8207 If set only some generic fallback builtins and possibly the content of
8209 describe the terminal to \*(UA.
8211 that this variable will only be queried once at program startup and can
8212 thus only be specified in resource files or on the command line.
8216 If defined, gives the number of lines of a message to be displayed
8219 normally, the first five lines are printed.
8223 The character set of the terminal \*(UA operates on,
8224 and the one and only supported character set that \*(UA can use if no
8225 character set conversion capabilities have been compiled into it,
8226 in which case it defaults to ISO-8859-1 unless it can deduce a value
8230 Refer to the section
8231 .Sx "Character sets"
8232 for the complete picture about character sets.
8235 .It Va user-HOST , user
8236 \*(IN Variable chain that sets a global fallback user name, which is
8237 used in case none has been given in the protocol and account-specific
8239 This variable defaults to the name of the user who runs \*(UA.
8243 \*(BO Setting this option enables upward compatibility with \*(UA
8244 version 15.0 in respect to which configuration options are available and
8245 how they are handled.
8246 This manual uses \*(IN and \*(OU to refer to the new and the old way of
8247 doing things, respectively.
8251 \*(BO Setting this option, also controllable via the command line option
8253 causes \*(UA to be more verbose, e.g., it will display obsoletion
8254 warnings and SSL/TLS certificate chains.
8255 Even though marked \*(BO this option may be set twice in order to
8256 increase the level of verbosity even more, in which case even details of
8257 the actual message delivery and protocol conversations are shown.
8260 is sufficient to disable verbosity as such.
8266 .It Va version , version-major , version-minor , version-update
8267 \*(RO \*(UA version information: the first variable contains a string
8268 containing the complete version identification \(en this is identical to
8269 the output of the command
8271 The latter three contain only digits: the major, minor and update
8275 .It Va writebackedited
8276 If this variable is set messages modified using the
8280 commands are written back to the current folder when it is quit;
8281 it is only honoured for writable folders in MBOX format, though.
8282 Note that the editor will be pointed to the raw message content in that
8283 case, i.e., neither MIME decoding nor decryption will have been
8284 performed, and proper RFC 4155
8286 quoting of newly added or edited content is also left as an excercise to
8290 .\" }}} (INTERNAL VARIABLES)
8293 .\" .Sh ENVIRONMENT {{{
8297 .Dq environment variable
8298 should be considered an indication that these variables are either
8299 standardized as vivid parts of process environments, or that they are
8300 commonly found in there.
8301 The process environment is inherited from the
8303 once \*(UA is started, and unless otherwise explicitly noted handling of
8304 the following variables transparently integrates into that of the
8305 .Sx "INTERNAL VARIABLES"
8306 from \*(UA's point of view.
8307 This means that, e.g., they can be managed via
8311 causing automatic program environment updates (to be inherited by
8312 newly created child processes).
8315 In order to transparently integrate other environment variables equally
8316 they need to be imported (linked) with the command
8318 This command can also be used to set and unset non-integrated
8319 environment variables from scratch, sufficient system support provided.
8320 The following example, applicable to a POSIX shell, sets the
8322 environment variable for \*(UA only, and beforehand exports the
8324 in order to affect any further processing in the running shell:
8326 .Bd -literal -offset indent
8327 $ EDITOR="vim -u ${HOME}/.vimrc"
8329 $ COLUMNS=80 \*(uA -R
8332 .Bl -tag -width ".It Ev _AILR_"
8335 The user's preferred width in column positions for the terminal screen
8337 Queried and used once on program startup, actively managed for child
8338 processes and the MLE (see
8339 .Sx "On terminal control and line editor" )
8340 in interactive mode thereafter.
8344 The name of the file to use for saving aborted messages if
8346 is set; this defaults to
8354 Pathname of the text editor to use in the
8358 .Sx "TILDE ESCAPES" .
8359 A default editor is used if this value is not defined.
8363 The user's home directory.
8364 This variable is only used when it resides in the process environment.
8371 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
8375 .Sx "Character sets" .
8376 (Only recognized by the system in the process environment.)
8380 The user's preferred number of lines on a page or the vertical screen
8381 or window size in lines.
8382 Queried and used once on program startup, actively managed for child
8383 processes in interactive mode thereafter.
8387 Pathname of the directory lister to use in the
8389 command when operating on local mailboxes.
8392 (path search through
8397 Upon startup \*(UA will actively ensure that this variable refers to the
8398 name of the user who runs \*(UA, in order to be able to pass a verified
8399 name to any newly created child process.
8403 Is used as the user's primary system mailbox, if set.
8404 Otherwise, a system-dependent default is used.
8405 Supports the special syntax conventions that are documented for the
8411 \*(OP Overrides the default path search for
8412 .Sx "The Mailcap files" ,
8413 which is defined in the standard RFC 1524 as
8414 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
8415 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8416 (\*(UA makes it a configuration option, however.)
8417 Note this is not a search path, but a path search.
8421 Is used as a startup file instead of
8424 When \*(UA scripts are invoked on behalf of other users,
8425 either this variable should be set to
8429 command line option should be used in order to avoid side-effects from
8430 reading their configuration files.
8431 This variable is only used when it resides in the process environment.
8435 The name of the user's mbox file.
8436 A logical subset of the special conventions that are documented for the
8441 The fallback default is
8446 Traditionally this secondary mailbox is used as the file to save
8447 messages from the primary system mailbox that have been read.
8449 .Sx "Message states" .
8452 .It Ev NAIL_NO_SYSTEM_RC
8453 If this variable is set then reading of
8455 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8456 had been started up with the option
8458 This variable is only used when it resides in the process environment.
8462 \*(IN\*(OP This variable overrides the default location of the user's
8468 Pathname of the program to use for backing the command
8472 variable enforces usage of a pager for output.
8473 The default paginator is
8475 (path search through
8478 \*(UA inspects the contents of this variable: if its contains the string
8480 then a non-existing environment variable
8487 dependent on whether terminal control support is available and whether
8488 that supports full (alternative) screen mode or not (also see
8489 .Sx "On terminal control and line editor" ) .
8493 will optionally be set to
8500 A list of directories that is searched by the shell when looking for
8501 commands (as such only recognized in the process environment).
8505 The shell to use for the commands
8511 and when starting subprocesses.
8512 A default shell is used if this option is not defined.
8516 \*(OP The terminal type for which output is to be prepared.
8517 For extended colour and font control please refer to
8518 .Sx "Coloured display" ,
8519 and for terminal management in general to
8520 .Sx "On terminal control and line editor" .
8524 Used as directory for temporary files instead of
8527 This variable is only used when it resides in the process environment.
8533 (see there), but this variable is not standardized, should therefore not
8534 be used, and is only corrected if already set.
8538 Pathname of the text editor to use in the
8542 .Sx "TILDE ESCAPES" .
8550 .Bl -tag -width ".It Pa _etc/mime.type_"
8552 File giving initial commands.
8555 System wide initialization file.
8559 \*(OP Personal MIME type handler definition file, see
8560 .Sx "The Mailcap files" .
8561 (RFC 1524 location, the actual path is a configuration option.)
8565 \*(OP System wide MIME type handler definition file, see
8566 .Sx "The Mailcap files" .
8567 (RFC 1524 location, the actual path is a configuration option.)
8570 .It Pa ~/.mime.types
8571 Personal MIME types, see
8572 .Sx "The mime.types files" .
8575 .It Pa /etc/mime.types
8576 System wide MIME types, see
8577 .Sx "The mime.types files" .
8581 \*(IN\*(OP The default location of the users
8583 file \(en the section
8584 .Sx "The .netrc file"
8585 documents the file format.
8588 .\" .Ss "The mime.types files" {{{
8589 .Ss "The mime.types files"
8591 When sending messages \*(UA tries to determine the content type of all
8593 When displaying message content or attachments \*(UA uses the content
8594 type to decide wether it can directly display data or wether it needs to
8595 deal with content handlers.
8596 It learns about MIME types and how to treat them by reading
8598 files, the loading of which can be controlled by setting the variable
8599 .Va mimetypes-load-control .
8602 can also be used to deal with MIME types.)
8604 files have the following syntax:
8607 .Dl type/subtype extension [extension ...]
8612 are strings describing the file contents, and one or multiple
8614 s, separated by whitespace, name the part of a filename starting after
8615 the last dot (of interest).
8616 Comments may be introduced anywhere on a line with a number sign
8618 causing the remaining line to be discarded.
8620 \*(UA also supports an extended, non-portable syntax in specially
8621 crafted files, which can be loaded via the alternative value syntax of
8622 .Va mimetypes-load-control
8623 and prepends an optional
8627 .Dl [type-marker ]type/subtype extension [extension ...]
8630 The following type markers are supported:
8633 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8635 Treat message parts with this content as plain text.
8640 Treat message parts with this content as HTML tagsoup.
8641 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8642 the content as plain text instead.
8646 but instead of falling back to plain text require an explicit content
8647 handler to be defined.
8652 for sending messages:
8654 .Va mime-allow-text-controls ,
8655 .Va mimetypes-load-control .
8656 For reading etc. messages:
8657 .Sx "HTML mail and MIME attachments" ,
8658 .Sx "The Mailcap files" ,
8660 .Va mime-counter-evidence ,
8661 .Va mimetypes-load-control ,
8662 .Va pipe-TYPE/SUBTYPE ,
8663 .Va pipe-EXTENSION .
8666 .\" .Ss "The Mailcap files" {{{
8667 .Ss "The Mailcap files"
8670 .Dq User Agent Configuration Mechanism
8671 which \*(UA \*(OPally supports.
8672 It defines a file format to be used to inform mail user agent programs
8673 about the locally-installed facilities for handling various data
8674 formats, i.e., about commands and how they can be used to display, edit
8675 etc. MIME part contents, as well as a default path search that includes
8676 multiple possible locations of
8680 environment variable that can be used to overwrite that (repeating here
8681 that it is not a search path, but instead a path search specification).
8682 Any existing files will be loaded in sequence, appending any content to
8683 the list of MIME type handler directives.
8687 files consist of a set of newline separated entries.
8688 Comment lines start with a number sign
8690 (in the first column!) and are ignored.
8691 Empty lines are also ignored.
8692 All other lines form individual entries that must adhere to the syntax
8694 To extend a single entry (not comment) its line can be continued on
8695 follow lines if newline characters are
8697 by preceding them with the backslash character
8699 The standard doesn't specify how leading whitespace of follow lines is
8700 to be treated, therefore \*(UA retains it.
8704 entries consist of a number of semicolon
8706 separated fields, and the backslash
8708 character can be used to escape any following character including
8709 semicolon and itself.
8710 The first two fields are mandatory and must occur in the specified
8711 order, the remaining fields are optional and may appear in any order.
8712 Leading and trailing whitespace of content is ignored (removed).
8715 The first field defines the MIME
8717 the entry is about to handle (case-insensitively, and no backslash
8718 escaping is possible in this field).
8719 If the subtype is specified as an asterisk
8721 the entry is ment to match all subtypes of the named type, e.g.,
8723 would match any audio type.
8724 The second field defines the shell command which shall be used to
8726 MIME parts of the given type; it is implicitly called the
8733 shell commands message (MIME part) data is passed via standard input
8734 unless the given shell command includes one or more instances of the
8737 in which case these instances will be replaced with a temporary filename
8738 and the data will have been stored in the file that is being pointed to.
8741 shell commands data is assumed to be generated on standard output unless
8742 the given command includes (one ore multiple)
8744 In any case any given
8746 format is replaced with a(n already) properly quoted filename.
8747 Note that when a command makes use of a temporary file via
8749 then \*(UA will remove it again, as if the
8750 .Cd x-mailx-tmpfile ,
8751 .Cd x-mailx-tmpfile-fill
8753 .Cd x-mailx-tmpfile-unlink
8754 flags had been set; see below for more.
8757 The optional fields either define a shell command or an attribute (flag)
8758 value, the latter being a single word and the former being a keyword
8759 naming the field followed by an equals sign
8761 succeeded by a shell command, and as usual for any
8763 content any whitespace surrounding the equals sign will be removed, too.
8764 Optional fields include the following:
8767 .Bl -tag -width textualnewlines
8769 A program that can be used to compose a new body or body part in the
8776 field, but is to be used when the composing program needs to specify the
8778 header field to be applied to the composed data.
8782 A program that can be used to edit a body or body part in the given
8787 A program that can be used to print a message or body part in the given
8792 Specifies a program to be run to test some condition, e.g., the machine
8793 architecture, or the window system in use, to determine whether or not
8794 this mailcap entry applies.
8795 If the test fails, a subsequent mailcap entry should be sought; also see
8796 .Cd x-mailx-test-once .
8798 .It Cd needsterminal
8799 This flag field indicates that the given shell command must be run on
8800 an interactive terminal.
8801 \*(UA will temporarily release the terminal to the given command in
8802 interactive mode, in non-interactive mode this entry will be entirely
8803 ignored; this flag implies
8804 .Cd x-mailx-noquote .
8806 .It Cd copiousoutput
8807 A flag field which indicates that the output of the
8809 command will be an extended stream of textual output that can be
8810 (re)integrated into \*(UA's normal visual display.
8811 It is mutually exclusive with
8814 .Cd x-mailx-always .
8816 .It Cd textualnewlines
8817 A flag field which indicates that this type of data is line-oriented and
8820 all newlines should be converted to canonical form (CRLF) before
8821 encoding, and will be in that form after decoding.
8825 This field gives a file name format, in which
8827 will be replaced by a random string, the joined combination of which
8828 will be used as the filename denoted by
8829 .Ev NAIL_FILENAME_TEMPORARY .
8830 One could specify that a GIF file being passed to an image viewer should
8831 have a name ending in
8834 .Ql nametemplate=%s.gif .
8835 Note that \*(UA ignores the name template unless that solely specifies
8836 a filename suffix that consists of (ASCII) alphabetic and numeric
8837 characters, the underscore and dot only.
8840 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8841 icon to be used to visually denote the presence of this kind of data.
8842 This field is not used by \*(UA.
8845 A textual description that describes this type of data.
8847 .It Cd x-mailx-always
8848 Extension flag field that denotes that the given
8850 command shall be executed even if multiple messages will be displayed
8852 Normally messages which require external viewers that produce output
8853 which doesn't integrate into \*(UA's visual display (i.e., don't have
8855 set) have to be addressed directly and individually.
8856 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8859 .It Cd x-mailx-even-if-not-interactive
8860 An extension flag test field \(em by default handlers without
8862 are entirely ignored in non-interactive mode, but if this flag is set
8863 then their use will be considered.
8864 It is an error if this flag is set for commands that use the flag
8867 .It Cd x-mailx-noquote
8868 An extension flag field that indicates that even a
8871 command shall not be used to generate message quotes
8872 (as it would be by default).
8874 .It Cd x-mailx-async
8875 Extension flag field that denotes that the given
8877 command shall be executed asynchronously, without blocking \*(UA.
8878 Cannot be used in conjunction with
8881 .It Cd x-mailx-test-once
8882 Extension flag which denotes wether the given
8884 command shall be evaluated once only and the (boolean) result be cached.
8885 This is handy if some global unchanging condition is to be queried, like
8886 .Dq running under the X Window System .
8888 .It Cd x-mailx-tmpfile
8889 Extension flag field that requests creation of a zero-sized temporary
8890 file, the name of which is to be placed in the environment variable
8891 .Ev NAIL_FILENAME_TEMPORARY .
8892 It is an error to use this flag with commands that include a
8896 .It Cd x-mailx-tmpfile-fill
8897 Normally the MIME part content is passed to the handler via standard
8898 input; if this flag is set then the data will instead be written into
8900 .Cd x-mailx-tmpfile .
8901 In order to cause deletion of the temporary file you will have to set
8902 .Cd x-mailx-tmpfile-unlink
8904 It is an error to use this flag with commands that include a
8908 .It Cd x-mailx-tmpfile-unlink
8909 Extension flag field that requests that the temporary file shall be
8910 deleted automatically when the command loop is entered again at latest.
8911 (Don't use this for asynchronous handlers.)
8912 It is an error to use this flag with commands that include a
8914 format, or without also setting
8917 .Cd x-mailx-tmpfile-fill .
8919 .It Cd x-mailx-tmpfile-keep
8922 implies the three tmpfile related flags above, but if you want, e.g.,
8924 and deal with the temporary file yourself, you can add in this flag to
8926 .Cd x-mailx-tmpfile-unlink .
8931 The standard includes the possibility to define any number of additional
8932 entry fields, prefixed by
8934 Flag fields apply to the entire
8936 entry \(em in some unusual cases, this may not be desirable, but
8937 differentiation can be accomplished via separate entries, taking
8938 advantage of the fact that subsequent entries are searched if an earlier
8939 one does not provide enough information.
8942 command needs to specify the
8946 command shall not, the following will help out the latter (with enabled
8950 level \*(UA will show informations about handler evaluation):
8952 .Bd -literal -offset indent
8953 application/postscript; ps-to-terminal %s; needsterminal
8954 application/postscript; ps-to-terminal %s; compose=idraw %s
8958 In fields any occurrence of the format string
8960 will be replaced by the
8963 Named parameters from the
8965 field may be placed in the command execution line using
8967 followed by the parameter name and a closing
8970 The entire parameter should appear as a single command line argument,
8971 regardless of embedded spaces; thus:
8973 .Bd -literal -offset indent
8975 Content-type: multipart/mixed; boundary=42
8978 multipart/*; /usr/local/bin/showmulti \e
8979 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8981 # Executed shell command
8982 /usr/local/bin/showmulti multipart/mixed 42
8986 .\" TODO v15: Mailcap: %n,%F
8987 Note that \*(UA doesn't support handlers for multipart MIME parts as
8988 shown in this example (as of today).
8989 \*(UA doesn't support the additional formats
8993 An example file, also showing how to properly deal with the expansion of
8995 which includes any quotes that are necessary to make it a valid shell
8996 argument by itself and thus will cause undesired behaviour when placed
8997 in additional user-provided quotes:
8999 .Bd -literal -offset indent
9001 text/richtext; richtext %s; copiousoutput
9003 text/x-perl; perl -cWT %s
9007 trap "rm -f ${infile}" EXIT\e; \e
9008 trap "exit 75" INT QUIT TERM\e; \e
9010 x-mailx-async; x-mailx-tmpfile-keep
9012 application/*; echo "This is \e"%t\e" but \e
9013 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
9014 copiousoutput; x-mailx-noquote
9019 .Sx "HTML mail and MIME attachments" ,
9020 .Sx "The mime.types files" ,
9023 .Va mime-counter-evidence ,
9024 .Va pipe-TYPE/SUBTYPE ,
9025 .Va pipe-EXTENSION .
9028 .\" .Ss "The .netrc file" {{{
9029 .Ss "The .netrc file"
9033 file contains user credentials for machine accounts.
9034 The default location in the user's
9036 directory may be overridden by the
9038 environment variable.
9039 The file consists of space, tabulator or newline separated tokens.
9040 \*(UA implements a parser that supports a superset of the original BSD
9041 syntax, but users should nonetheless be aware of portability glitches
9042 of that file format, shall their
9044 be usable across multiple programs and platforms:
9047 .Bl -bullet -compact
9049 BSD doesn't support single, but only double quotation marks, e.g.,
9050 .Ql password="pass with spaces" .
9052 BSD (only?) supports escaping of single characters via a backslash
9053 (e.g., a space can be escaped via
9055 in- as well as outside of a quoted string.
9057 BSD doesn't require the final quotation mark of the final user input token.
9059 The original BSD (Berknet) parser also supported a format which allowed
9060 tokens to be separated with commas \(en whereas at least Hewlett-Packard
9061 still seems to support this syntax, \*(UA does not!
9063 As a non-portable extension some widely-used programs support
9064 shell-style comments: if an input line starts, after any amount of
9065 whitespace, with a number sign
9067 then the rest of the line is ignored.
9069 Whereas other programs may require that the
9071 file is accessible by only the user if it contains a
9077 \*(UA will always require these strict permissions.
9081 Of the following list of supported tokens \*(UA only uses (and caches)
9086 At runtime the command
9088 can be used to control \*(UA's
9092 .Bl -tag -width password
9093 .It Cd machine Ar name
9094 The hostname of the entries' machine, lowercase-normalized by \*(UA
9096 Any further file content, until either end-of-file or the occurrence
9101 first-class token is bound (only related) to the machine
9104 As an extension that shouldn't be the cause of any worries
9105 \*(UA supports a single wildcard prefix for
9107 .Bd -literal -offset indent
9108 machine *.example.com login USER password PASS
9109 machine pop3.example.com login USER password PASS
9110 machine smtp.example.com login USER password PASS
9116 .Ql pop3.example.com ,
9120 .Ql local.smtp.example.com .
9121 Note that in the example neither
9122 .Ql pop3.example.com
9124 .Ql smtp.example.com
9125 will be matched by the wildcard, since the exact matches take
9126 precedence (it is however faster to specify it the other way around).
9131 except that it is a fallback entry that is used shall none of the
9132 specified machines match; only one default token may be specified,
9133 and it must be the last first-class token.
9135 .It Cd login Ar name
9136 The user name on the remote machine.
9138 .It Cd password Ar string
9139 The user's password on the remote machine.
9141 .It Cd account Ar string
9142 Supply an additional account password.
9143 This is merely for FTP purposes.
9145 .It Cd macdef Ar name
9147 A macro is defined with the specified
9149 it is formed from all lines beginning with the next line and continuing
9150 until a blank line is (consecutive newline characters are) encountered.
9153 entries cannot be utilized by multiple machines, too, but must be
9154 defined following the
9156 they are intended to be used with.)
9159 exists, it is automatically run as the last step of the login process.
9160 This is merely for FTP purposes.
9167 .\" .Sh EXAMPLES {{{
9170 .\" .Ss "An example configuration" {{{
9171 .Ss "An example configuration"
9173 .Bd -literal -offset indent
9174 # This example assumes v15.0 compatibility mode
9177 # Where are the up-to-date SSL certificates?
9178 #set ssl-ca-dir=/etc/ssl/certs
9179 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
9181 # (Since we manage up-to-date ones explicitly, don't use any,
9182 # possibly outdated, default certificates shipped with OpenSSL
9183 set ssl-no-default-ca
9185 # Don't use protocols older than TLS v1.2.
9186 # Change this only when the remote server doesn't support it:
9187 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
9188 # such explicit exceptions, then
9189 set ssl-protocol='-ALL,+TLSv1.2'
9191 # Explicitly define the list of ciphers, which may improve security,
9192 # especially with protocols older than TLS v1.2. See ciphers(1).
9193 # Hint: it is important to include "@STRENGTH": only with it the
9194 # final list will be sorted by algorithm strength.
9195 # This is an example: in reality it is possibly best to only use
9196 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
9197 set ssl-cipher-list='ALL:!aNULL:!MEDIUM:!LOW:\e
9198 !MD5:!RC4:!EXPORT:@STRENGTH'
9200 # Request strict transport security checks!
9201 set ssl-verify=strict
9203 # Essential setting: select allowed character sets
9204 set sendcharsets=utf-8,iso-8859-1
9206 # A very kind option: when replying to a message, first try to
9207 # use the same encoding that the original poster used herself!
9208 set reply-in-same-charset
9210 # When replying to or forwarding a message the comment and name
9211 # parts of email addresses are removed unless this variable is set
9214 # When sending messages, wait until the Mail-Transfer-Agent finishs.
9215 # Only like this you'll be able to see errors reported through the
9216 # exit status of the MTA (including the builtin SMTP one)!
9219 # Only use builtin MIME types, no mime.types(5) files
9220 set mimetypes-load-control
9222 # Default directory where we act in (relative to $HOME)
9224 # A leading "+" (often) means: under *folder*
9225 # *record* is used to save copies of sent messages
9226 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
9228 # Make "file mymbox" and "file myrec" go to..
9229 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
9231 # Not really optional, e.g., for S/MIME
9232 set from='Your Name <address@exam.ple>'
9234 # It may be necessary to set hostname and/or smtp-hostname
9235 # if the "SERVER" of smtp and "domain" of from don't match.
9236 # The `urlencode' command can be used to encode USER and PASS
9237 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
9238 smtp-auth=login/plain... \e
9241 # Never refuse to start into interactive mode, and more
9243 colour-pager crt= \e
9244 followup-to followup-to-honour=ask-yes \e
9245 history-file=+.\*(uAhist history-size=-1 history-gabby \e
9246 mime-counter-evidence=0xE \e
9247 prompt='?\e?[\e$ \e@]\e& ' \e
9248 reply-to-honour=ask-yes
9250 # When `t'yping messages, show only these headers
9251 # (use `T'ype for all headers and `S'how for raw message)
9252 retain date from to cc subject
9254 # Some mailing lists
9255 mlist '@xyz-editor\e.xyz'$ '@xyzf\e.xyz$'
9256 mlsubscribe '^xfans@xfans\e.xyz$'
9258 # A real life example of a very huge free mail provider
9260 set folder=~/spool/XooglX MAIL=+syste.mbox sent=+sent
9261 set from='Your Name <address@examp.ple>'
9262 # (The plain smtp:// proto is optional)
9263 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
9266 # Here is a pretty large one which does not allow sending mails
9267 # if there is a domain name mismatch on the SMTP protocol level,
9268 # which would bite us if the value of from does not match, e.g.,
9269 # for people who have a sXXXXeforge project and want to speak
9270 # with the mailing list under their project account (in from),
9271 # still sending the message through their normal mail provider
9273 set folder=~/spool/XandeX MAIL=+syste.mbox sent=+sent
9274 set from='Your Name <address@exam.ple>'
9275 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
9276 hostname=yaXXex.com smtp-hostname=
9279 # Create some new commands so that, e.g., `ls /tmp' will..
9290 ghost llS !ls -aFlrS
9293 # We don't support gpg(1) directly yet. But simple --clearsign'd
9294 # message parts can be dealt with as follows:
9296 wysh set pipe-text/plain=$'@*#++=@\e
9297 < "${NAIL_FILENAME_TEMPORARY}" awk \e
9298 -v TMPFILE="${NAIL_FILENAME_TEMPORARY}" \e'\e
9300 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/{\e
9303 print "--- GPG --verify ---";\e
9304 system("gpg --verify " TMPFILE " 2>&1");\e
9305 print "--- GPG --verify ---";\e
9309 /^-----BEGIN PGP SIGNATURE-----/,\e
9310 /^-----END PGP SIGNATURE-----/{\e
9320 !printf 'Key IDs to gpg --recv-keys: ';\e
9322 gpg --recv-keys ${keyids};
9328 When storing passwords in
9330 appropriate permissions should be set on this file with
9331 .Ql $ chmod 0600 \*(ur .
9334 is available user credentials can be stored in the central
9336 file instead; e.g., here is a different version of the example account
9337 that sets up SMTP and POP3:
9339 .Bd -literal -offset indent
9341 set folder=~/spool/XandeX MAIL=+syste.mbox sent=+sent
9342 set from='Your Name <address@exam.ple>'
9344 #set agent-shell-lookup='gpg -d .pass.gpg'
9346 set smtp=smtps://smtp.yXXXXx.ru:465 \e
9347 smtp-hostname= hostname=yXXXXx.com
9348 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
9349 ghost xp fi pop3s://pop.yXXXXx.ru
9358 .Bd -literal -offset indent
9359 machine *.yXXXXx.ru login USER password PASS
9364 .Va agent-shell-lookup
9365 is available things could be diversified further by using encrypted
9366 password storage: for this, don't specify
9370 file and instead uncomment the line that defines agent lookup in the
9373 above, then create the encrypted password storage file
9376 .Bd -literal -offset indent
9379 $ eval `gpg-agent --daemon \e
9380 --pinentry-program=/usr/bin/pinentry-curses \e
9381 --max-cache-ttl 99999 --default-cache-ttl 99999`
9385 This configuration should now work just fine (use the
9387 command line option for a(n almost) dry-run):
9390 .Dl $ echo text | \*(uA -vv -AXandeX -s Subject user@exam.ple
9393 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
9394 .Ss "Signed and encrypted messages with S/MIME"
9396 \*(OP S/MIME provides two central mechanisms:
9397 message signing and message encryption.
9398 A signed message contains some data in addition to the regular text.
9399 The data can be used to verify that the message was sent using a valid
9400 certificate, that the sender's address in the message header matches
9401 that in the certificate, and that the message text has not been altered.
9402 Signing a message does not change its regular text;
9403 it can be read regardless of whether the recipient's software is able to
9407 It is thus usually possible to sign all outgoing messages if so desired.
9408 Encryption, in contrast, makes the message text invisible for all people
9409 except those who have access to the secret decryption key.
9410 To encrypt a message, the specific recipient's public encryption key
9412 It is therefore not possible to send encrypted mail to people unless their
9413 key has been retrieved from either previous communication or public key
9415 A message should always be signed before it is encrypted.
9416 Otherwise, it is still possible that the encrypted message text is
9420 A central concept to S/MIME is that of the certification authority (CA).
9421 A CA is a trusted institution that issues certificates.
9422 For each of these certificates it can be verified that it really
9423 originates from the CA, provided that the CA's own certificate is
9425 A set of CA certificates is usually delivered with OpenSSL and installed
9427 If you trust the source of your OpenSSL software installation,
9428 this offers reasonable security for S/MIME on the Internet.
9430 .Va ssl-no-default-ca
9434 .Va smime-ca-dir . )
9435 In general, a certificate cannot be more secure than the method its CA
9436 certificate has been retrieved with, though.
9437 Thus if you download a CA certificate from the Internet,
9438 you can only trust the messages you verify using that certificate as
9439 much as you trust the download process.
9442 The first thing you need for participating in S/MIME message exchange is
9443 your personal certificate, including a private key.
9444 The certificate contains public information, in particular your name and
9445 your email address(es), and the public key that is used by others to
9446 encrypt messages for you,
9447 and to verify signed messages they supposedly received from you.
9448 The certificate is included in each signed message you send.
9449 The private key must be kept secret.
9450 It is used to decrypt messages that were previously encrypted with your
9451 public key, and to sign messages.
9454 For personal use it is recommended that you get a S/MIME certificate
9455 from one of the major CAs on the Internet using your WWW browser.
9456 Many CAs offer such certificates for free.
9458 .Lk https://www.CAcert.org
9459 which issues client and server certificates to members of their
9460 community for free; their root certificate
9461 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9462 is often not in the default set of trusted CA root certificates, though,
9463 which means you will have to download their root certificate separately
9464 and ensure it is part of our S/MIME certificate validation chain by
9467 or as a vivid member of the
9469 But let's take a step-by-step tour on how to setup S/MIME with
9470 a certificate from CAcert.org despite this situation!
9473 First of all you will have to become a member of the CAcert.org
9474 community, simply by registrating yourself via the web interface.
9475 Once you are, create and verify all email addresses you want to be able
9476 to create signed and encrypted messages for/with using the corresponding
9477 entries of the web interface.
9478 Now ready to create S/MIME certificates, so let's create a new
9479 .Dq client certificate ,
9480 ensure to include all email addresses that should be covered by the
9481 certificate in the following web form, and also to use your name as the
9485 Create a private key and a certificate request on your local computer
9486 (please see the manual pages of the used commands for more in-depth
9487 knowledge on what the used arguments etc. do):
9490 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9493 Afterwards copy-and-paste the content of
9495 into the certificate-request (CSR) field of the web form on the
9496 CAcert.org website (you may need to unfold some
9497 .Dq advanced options
9498 to see the corresponding text field).
9499 This last step will ensure that your private key (which never left your
9500 box) and the certificate belong together (through the public key that
9501 will find its way into the certificate via the certificate-request).
9502 You are now ready and can create your CAcert certified certificate.
9503 Download and store or copy-and-paste it as
9508 In order to use your new S/MIME setup you will have to create
9509 a combined private key/public key (certificate) file:
9512 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9515 This is the file \*(UA will work with.
9516 If you have created your private key with a passphrase then \*(UA will
9517 ask you for it whenever a message is signed or decrypted.
9518 Set the following variables to henceforth use S/MIME (setting
9520 is of interest for verification only):
9522 .Bd -literal -offset indent
9523 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9524 smime-sign-cert=ME@HERE.com.paired \e
9525 smime-sign-message-digest=SHA256 \e
9530 From each signed message you send, the recipient can fetch your
9531 certificate and use it to send encrypted mail back to you.
9532 Accordingly if somebody sends you a signed message, you can do the same,
9535 command to check the validity of the certificate.
9538 Variables of interest for S/MIME signing:
9542 .Va smime-crl-file ,
9543 .Va smime-no-default-ca ,
9545 .Va smime-sign-cert ,
9546 .Va smime-sign-include-certs
9548 .Va smime-sign-message-digest .
9551 After it has been verified save the certificate via
9553 and tell \*(UA that it should use it for encryption for further
9554 communication with that somebody:
9556 .Bd -literal -offset indent
9558 set smime-encrypt-USER@HOST=FILENAME \e
9559 smime-cipher-USER@HOST=AES256
9563 Additional variables of interest for S/MIME en- and decryption:
9566 .Va smime-encrypt-USER@HOST .
9569 You should carefully consider if you prefer to store encrypted messages
9571 If you do, anybody who has access to your mail folders can read them,
9572 but if you do not, you might be unable to read them yourself later if
9573 you happen to lose your private key.
9576 command saves messages in decrypted form, while the
9580 commands leave them encrypted.
9583 Note that neither S/MIME signing nor encryption applies to message
9584 subjects or other header fields yet.
9585 Thus they may not contain sensitive information for encrypted messages,
9586 and cannot be trusted even if the message content has been verified.
9587 When sending signed messages,
9588 it is recommended to repeat any important header information in the
9592 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9593 .Ss "Using CRLs with S/MIME or SSL/TLS"
9595 \*(OP Certification authorities (CAs) issue certificate revocation
9596 lists (CRLs) on a regular basis.
9597 These lists contain the serial numbers of certificates that have been
9598 declared invalid after they have been issued.
9599 Such usually happens because the private key for the certificate has
9601 because the owner of the certificate has left the organization that is
9602 mentioned in the certificate, etc.
9603 To seriously use S/MIME or SSL/TLS verification,
9604 an up-to-date CRL is required for each trusted CA.
9605 There is otherwise no method to distinguish between valid and
9606 invalidated certificates.
9607 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9608 the Internet, so you have to retrieve them by some external mechanism.
9611 \*(UA accepts CRLs in PEM format only;
9612 CRLs in DER format must be converted, like, e.\|g.:
9615 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9618 To tell \*(UA about the CRLs, a directory that contains all CRL files
9619 (and no other files) must be created.
9624 variables, respectively, must then be set to point to that directory.
9625 After that, \*(UA requires a CRL to be present for each CA that is used
9626 to verify a certificate.
9629 .\" .Ss "Handling spam" {{{
9632 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9633 identification of, and, in general, dealing with spam messages.
9634 A precondition of most commands in order to function is that the
9636 variable is set to one of the supported interfaces.
9637 Once messages have been identified as spam their (volatile)
9639 state can be prompted: the
9643 message specifications will address respective messages and their
9645 entries will be used when displaying the
9647 in the header display.
9652 rates the given messages and sets their
9655 If the spam interface offers spam scores those can also be displayed in
9656 the header display by including the
9666 will interact with the Bayesian filter of the chosen interface and learn
9667 the given messages as
9671 respectively; the last command can be used to cause
9673 of messages; it adheres to their current
9675 state and thus reverts previous teachings.
9680 will simply set and clear, respectively, the mentioned volatile
9682 message flag, without any interface interaction.
9689 .Va spam-interface Ns s
9693 require a running instance of the
9695 server in order to function, started with the option
9697 shall Bayesian filter learning be possible.
9699 only works via a local path-based
9701 socket, but otherwise the following will be equivalently fine:
9703 .Bd -literal -offset indent
9704 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9705 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9706 --daemonize [--local] [--allow-tell]
9710 Thereafter \*(UA can make use of these interfaces:
9712 .Bd -literal -offset indent
9713 $ \*(uA -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9714 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9716 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9717 -Sspamc-command=/usr/local/bin/spamc \e
9718 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9720 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9721 -Sspamc-command=/usr/local/bin/spamc \e
9722 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9726 Using the generic filter approach allows usage of programs like
9730 Here is an example for the former, requiring it to be accessible via
9733 .Bd -literal -offset indent
9734 $ \*(uA -Sspam-interface=filter -Sspam-maxsize=500000 \e
9735 -Sspamfilter-ham="bogofilter -n" \e
9736 -Sspamfilter-noham="bogofilter -N" \e
9737 -Sspamfilter-nospam="bogofilter -S" \e
9738 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9739 -Sspamfilter-spam="bogofilter -s" \e
9740 -Sspamfilter-rate-scanscore="1;^(.+)$"
9744 Because messages must exist on local storage in order to be scored (or
9745 used for Bayesian filter training), it is possibly a good idea to
9746 perform the local spam check last:
9748 .Bd -literal -offset indent
9749 define spamdelhook {
9751 spamset (header x-dcc-brand-metrics "bulk")
9752 # Server-side spamassassin(1)
9753 spamset (header x-spam-flag "YES")
9754 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9760 set folder-hook-FOLDER=spamdelhook
9764 See also the documentation for the variables
9765 .Va spam-interface , spam-maxsize ,
9766 .Va spamc-command , spamc-arguments , spamc-user ,
9767 .Va spamd-socket , spamd-user ,
9768 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9771 .Va spamfilter-rate-scanscore .
9779 .\" .Ss "\*(UA shortly hangs on startup" {{{
9780 .Ss "\*(UA shortly hangs on startup"
9782 This can have two reasons, one is the necessity to wait for a file lock
9783 and can't be helped, the other being that \*(UA calls the function
9785 in order to query the nodename of the box (sometimes the real one is
9786 needed instead of the one represented by the internal variable
9788 You may have varying success by ensuring that the real hostname and
9792 or, more generally, that the name service is properly setup \(en
9795 return what you'd expect?
9796 Does this local hostname has a domain suffix?
9797 RFC 6762 standardized the link-local top-level domain
9801 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9802 .Ss "I can't login to Google mail a.k.a. GMail"
9804 Since 2014 some free service providers classify programs as
9806 unless they use a special authentification method (OAuth 2.0) which
9807 wasn't standardized for non-HTTP protocol authentication token query
9808 until August 2015 (RFC 7628).
9811 Different to Kerberos / GSSAPI, which is developed since the mid of the
9812 1980s, where a user can easily create a local authentication ticket for
9813 her- and himself with the locally installed
9815 program, that protocol has no such local part but instead requires
9816 a world-wide-web query to create or fetch a token; since there is no
9817 local cache this query has to be performed whenever \*(UA is invoked
9818 from the command line (in interactive sessions situation may differ).
9821 \*(UA doesn't support OAuth.
9822 Because of this it is necessary to declare \*(UA a
9824 (on the providers account web page) in order to read and send mail.
9825 However, it also seems possible to take the following steps instead:
9830 give the provider the number of a mobile phone,
9833 .Dq 2-Step Verification ,
9835 create an application specific password (16 characters), and
9837 use that special password instead of your real Google account password in
9838 S-nail (for more on that see the section
9839 .Sx "On URL syntax and credential lookup" ) .
9845 .\" .Sh "SEE ALSO" {{{
9863 .Xr spamassassin 1 ,
9889 M. Douglas McIlroy writes in his article
9890 .Dq A Research UNIX Reader: Annotated Excerpts \
9891 from the Programmer's Manual, 1971-1986
9894 command already appeared in First Edition
9898 .Bd -ragged -offset indent
9899 Electronic mail was there from the start.
9900 Never satisfied with its exact behavior, everybody touched it at one
9901 time or another: to assure the safety of simultaneous access, to improve
9902 privacy, to survive crashes, to exploit uucp, to screen out foreign
9903 freeloaders, or whatever.
9904 Not until v7 did the interface change (Thompson).
9905 Later, as mail became global in its reach, Dave Presotto took charge and
9906 brought order to communications with a grab-bag of external networks
9912 Mail was written in 1978 by Kurt Shoens and developed as part of the
9915 distribution until 1995.
9916 Mail has then seen further development in open source
9918 variants, noticeably by Christos Zoulas in
9920 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9921 Ritter in the years 2000 until 2008.
9922 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9923 This man page is derived from
9924 .Dq The Mail Reference Manual
9925 that was originally written by Kurt Shoens.
9932 .An "Christos Zoulas" ,
9933 .An "Gunnar Ritter" ,
9934 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9936 .Mt s-mailx@sdaoden.eu ) .
9942 The character set conversion uses and relies upon the
9945 Its functionality differs widely between the various system environments
9949 Limitations with POP3 mailboxes are:
9950 It is not possible to edit messages, they can only be copied and deleted.
9951 The line count for the header display is only appropriate if the entire
9952 message has been downloaded from the server.
9953 The status field of a message is maintained by the server between
9954 connections; some servers do not update it at all, and with a server
9957 command will not cause the message status to be reset.
9962 variable have no effect.
9963 It is not possible to rename or to remove POP3 mailboxes.
9970 is typed while a POP3 operation is in progress, \*(UA will wait
9971 until the operation can be safely aborted, and will then return to the
9972 command loop and print the prompt again.
9975 is typed while \*(UA is waiting for the operation to complete, the
9976 operation itself will be cancelled.
9977 In this case, data that has not been fetched yet will have to be fetched
9978 before the next command can be performed.
9979 If the cancelled operation was using an SSL/TLS encrypted channel,
9980 an error in the SSL transport will very likely result and render the
9981 connection unusable.
9984 As \*(UA is a mail user agent, it provides only basic SMTP services.
9985 If it fails to contact its upstream SMTP server, it will not make
9986 further attempts to transfer the message at a later time,
9987 and it does not leave other information about this condition than an
9988 error message on the terminal and an entry in
9990 This is usually not a problem if the SMTP server is located in the same
9991 local network as the computer on which \*(UA is run.
9992 However, care should be taken when using a remote server of an ISP;
9993 it might be better to set up a local SMTP server then which just acts as
9997 \*(UA immediately contacts the SMTP server (or
9999 It would not make much sense for \*(UA to defer outgoing mail since SMTP
10000 servers usually provide much more elaborated delay handling than \*(UA
10001 could perform as a client.
10009 from the distribution or the repository.
10011 After deleting some message of a POP3 mailbox the header summary falsely
10012 claims that there are no messages to display, you need to perform
10013 a scroll or dot movement to restore proper state.
10015 In threaded display a power user may encounter crashes very
10016 occasionally (this is may and very).