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]
66 .Nd send and receive Internet mail
79 .Op Fl a Ar attachment
82 .Op Fl q Ar quote-file
84 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
89 .Op Fl Fl \~ Ns Ar mta-option ...
98 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
101 .Op Fl Fl \~ Ns Ar mta-option ...
108 .Op Fl L Ar spec-list
109 .Op Fl r Ar from-addr
110 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
113 .Op Fl Fl \~ Ns Ar mta-option ...
118 .Mx -toc -tree html pdf ps xhtml
121 .\" .Sh DESCRIPTION {{{
124 .Bd -filled -compact -offset indent
125 .Sy Compatibility note:
126 S-nail (\*(UA) will wrap up into \%S-mailx in v15.0 (circa 2018).
127 A partial set of compatibility options exist, tagged as \*(IN and \*(OU,
128 yet complete compatibility won't be possible.
129 To choose upward compatible behaviour, please set the internal variable
131 Anything which will vanish in v15.0 is tagged \*(OB, and using
133 will print warnings for many use cases of obsolete features.
137 \*(UA is a mail processing system with a command syntax reminiscent of
139 with lines replaced by messages.
140 It is intended to provide the functionality of the POSIX
142 command, but is MIME capable and optionally offers extensions for
143 line editing, S/MIME, SMTP and POP3 among others.
144 It is usable as a mail batch language.
146 .\" .Ss "Options" {{{
149 .Bl -tag -width ".Fl _ Ar _ccount"
152 Explicitly control which of the
154 shall be loaded: if the letter
156 is (case-insensitively) part of the
160 is loaded, likewise the letter
162 controls loading of the user's personal
164 file, whereas the letters
168 explicitly forbid loading of any resource files.
169 This option should be used by scripts: to avoid environmental noise they
172 from any configuration files and create a script-local environment,
173 explicitly setting any desired variable via
175 This option overrides
182 command (see below) for
184 after the startup files have been read.
188 Attach the given file to the message.
189 The same filename conventions as described in the section
191 apply: shell word expansion is restricted to the tilde
196 not be accessible but contain a
198 character, then anything after the
200 is assumed to specify the input character set and anything before
202 the filename: this is the only option to specify the input character set
203 (and don't perform any character set conversion) for text attachments
204 from the command line, not using the
206 tilde escape command.
210 Make standard input and standard output line-buffered.
214 Send a blind carbon copy to
216 Can be used multiple times, but it is also possible to give
217 a comma-separated list of receivers in a single argument, proper shell
218 quoting provided, e.g.,
219 .Ql -b """qrec1 , rec2,rec3, Ex <am@ple>""" .
221 .Sx "On sending mail, and non-interactive mode" .
225 Send carbon copies to the given receiver(s).
226 Can be used multiple times.
232 variable which enables debug messages and disables message delivery,
233 among others; effectively turns almost any operation into a dry-run.
239 variable and thus discard messages with an empty message part body.
240 This is useful for sending messages from scripts.
244 Just check if mail is present (in the specified or system mailbox).
245 If yes, return an exit status of zero, a non-zero value otherwise.
246 To restrict the set of mails to consider in this evaluation a message
247 specification can be added with the option
252 Save the message to send in a file named after the local part of the
253 first recipient's address (instead of in
258 Read in the contents of the user's
260 (or the specified file) for processing;
261 when \*(UA is quit, it writes undeleted messages back to this file
265 Some special conventions are recognized for the string
267 which are documented for the
272 is not a direct argument to the flag
274 but is instead taken from the command line after option processing has
278 that starts with a hyphen, prefix it with a (relative) path, as in
279 .Ql ./-hyphenbox.mbox .
283 Display a summary of the
285 of all messages in the specified or system mailbox and exit.
286 A configurable summary view is available via the
292 Show a short usage summary.
293 Because of widespread use a
295 argument will have the same effect.
301 variable to ignore tty interrupt signals.
304 .It Fl L Ar spec-list
305 Display a summary of all
307 of only those messages in the specified or system mailbox that match the
312 .Sx "Specifying messages"
319 option has been given in addition no header summary is produced,
320 but \*(UA will instead indicate via its exit status wether
326 note that any verbose output is suppressed in this mode and must instead
327 be enabled explicitly (e.g., by using the option
334 variable and thus inhibit initial display of message headers when
335 reading mail or editing a mail folder.
339 Standard flag that inhibits reading the system wide
344 allows more control over the startup sequence; also see
345 .Sx "Resource files" .
349 Initialize the message body with the contents of the specified file,
350 which may be standard input
352 only in non-interactive context.
353 May be given in send mode only.
357 Any folder opened will be in read-only mode.
363 is a valid address then it specifies the envelope sender address to be
366 when a message is send.
369 include a user name, comments etc., then the components will be
370 separated and the name part will be passed to the MTA individually via
374 will also be assigned to the
376 variable, just as if additionally
378 had been specified (therefore affecting SMTP data transfer, too).
380 If instead an empty string is passed as
382 then the content of the variable
384 will be evaluated and used for this purpose whenever the MTA is
386 Note that \*(UA by default, without
388 that is, neither passes
392 flags to the MTA by itself.
395 .It Fl S Ar variable Ns Op = Ns value
396 Sets the internal option
398 and, in case of a value option, assigns
401 Even though variables set via
403 may be overwritten from within resource files,
404 the command line setting will be reestablished after all resource files
409 Specify the subject of the to-be-sent message.
413 The message given (on standard input) is expected to contain, separated
414 from the message body with an empty line, a message header with
419 fields giving its recipients, which will be added to those given on the
421 If a message subject is specified via
423 then it'll be used in favour of one given on the command line.
432 Note you can also specify
436 and the envelope address possibly specified with the option
439 The following, which are normally created automatically based
440 upon the message context, can also be specified:
445 .Ql Mail-Followup-To:
446 (special address massage will however still occur for the latter).
447 In fact custom header fields may also be used, the content of which
448 is passed through unchanged.
452 can be embedded, too.
456 Read the system mailbox of
458 (appropriate privileges presumed), and
461 in some aspects, e.g. in respect to
470 Show \*(UA's version and exit.
476 option enables display of some informational context messages.
477 Using it twice increases the level of verbosity.
483 to the list of commands to be executed before normal operation starts.
487 .Va batch-exit-on-error ;
488 the only possibility to execute commands in non-interactive mode when
489 reading startup files is actively prohibited.
495 even if not in interactive mode.
500 In batch mode the full set of commands is available, just like in
501 interactive mode, and diverse variable settings and internal states are
502 adjusted for batch necessities, e.g., it sets
513 It also enables processing of
514 .Sx "TILDE ESCAPES" .
515 E.g., the following should send an email message to
517 .Bd -literal -offset indent
518 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en~.\enx\en' | \e
519 LC_ALL=C \*(ua -:/ -d#
524 This flag forces termination of option processing in order to prevent
527 It also forcefully puts \*(UA into send mode, see
528 .Sx "On sending mail, and non-interactive mode" .
532 In the above list of supported command line options,
536 are implemented by means of setting the respective option, as via
539 .Op Ar mta-option ...
541 arguments that are given at the end of the command line after a
543 separator will be passed through to the mail-transfer-agent (MTA) and
544 persist for an entire (interactive) session \(en if the setting of
546 allows their recognition;
547 MTA arguments can also be specified in the variable
548 .Va sendmail-arguments ;
549 find MTA interaction described in more detail in the documentation of
551 MTA arguments are ignored when mail is send via SMTP data transfer.
554 .\" .Ss "A starter" {{{
557 \*(UA is a direct descendant of
559 Mail, a successor of the Research
562 .Dq was there from the start
567 Mail reference manual begins with the following words:
569 .Bd -ragged -offset indent
570 Mail provides a simple and friendly environment for sending and
572 It divides incoming mail into its constituent messages and allows the
573 user to deal with them in any order.
574 In addition, it provides a set of
576 -like commands for manipulating messages and sending mail.
577 Mail offers the user simple editing capabilities to ease the composition
578 of outgoing messages, as well as providing the ability to define and
579 send to names which address groups of users.
583 \*(UA is thus the user side of the
585 mail system, whereas the system side (mail-transfer-agent, MTA) was
586 traditionally taken by
592 are often used for this purpose instead.
593 If the \*(OPal SMTP is included in the
595 of \*(UA then the system side is not a mandatory precondition for mail
599 Because \*(UA strives for compliance with POSIX
601 it is likely that some configuration settings have to be adjusted before
602 using it is a smooth experience.
605 file already bends those standard settings a bit towards more user
606 friendliness and safety, e.g., it sets the
610 variables in order to suppress the automatic moving of messages to
612 that would otherwise occur (see
613 .Sx "Message states" )
616 to not remove empty files in order not to mangle file permissions when
617 files eventually get recreated.
620 option so that by default file grouping (via the
622 prefix as documented also for
627 contains some further suggestions.
630 .\" .Ss "On sending mail, and non-interactive mode" {{{
631 .Ss "On sending mail, and non-interactive mode"
633 To send a message to one or more people, using a local
634 mail-transfer-agent (MTA; the executable path can be set via
636 or the \*(OPal builtin SMTP (set and see the variable
638 transport to actually deliver the generated mail message, \*(UA can be
639 invoked with arguments which are the names of people to whom the mail
642 .Bd -literal -offset indent
643 $ \*(ua -s Subject -a attachm.ent bill@host1 'Bob <bob@host2>'
644 # But... try it in an isolated dry-run mode first
645 $ LC_ALL=C \*(ua -:/ -d -vv -Sfrom="me <he@exam.ple>" \e
646 -b bcc@exam.ple -c cc@exam.ple \e
647 -s Subject -. "(Lovely) Bob <bob@host2>"
651 The command line options
655 can be used to add (blind) carbon copy receivers.
656 Almost always lists of addresses can be given where an address is
658 whereas comma-separated lists should be given, e.g.,
659 .Ql -c """r1@exam.ple , r2@exam.ple,r3@exam.ple""" ,
660 that very example could also be given as the whitespace-separated list
661 .Ql -c """r1@exam.ple r2@exam.ple r3@exam.ple""" ,
662 but which for obvious reasons would not work for
663 .Ql -c """R1 <r1@exam.ple>, R2 (heh!) <r2@exam.ple>""" .
666 The user is then expected to type in the message contents.
667 In this compose mode \*(UA treats lines beginning with the character
669 special \(en these are so-called
671 which can be used to read in files, process shell commands, add and edit
672 attachments and more; e.g., the tilde escape
674 will start the text editor to revise the message in it's current state,
676 allows editing of the message recipients and
678 gives an overview of available tilde escapes.
682 at the beginning of an empty line leaves compose mode and causes the
683 message to be sent, whereas typing
686 twice will abort the current letter (saving its contents in the file
694 A number of variables can be used to alter default behavior; e.g.,
699 will automatically startup a text editor when compose mode is entered,
701 will cause the user to be prompted actively for carbon-copy recipients
704 option will allow leaving compose mode by writing a line consisting
709 Very important, though, is to define which
711 may be used when sending messages, usually by setting the option
714 having read the section
715 .Sx "The mime.types files"
716 to understand how the MIME-type of outgoing attachments is classified
717 and the knowledge that messages are sent asynchronously unless
719 is set: only with it MTA delivery errors will be recognizable.
724 is often necessary (e.g., in conjunction with
726 or desirable, you may want to do some dry-run tests before you go.
727 Saving a copy of the sent messages in a
729 may also be desirable \(en as for most mailbox file targets some
730 special conventions are recognized, see the
732 command for more on that.
734 .Sx "On URL syntax and credential lookup"
735 will spread some light on the
737 variable chains as well as on using URLs for accessing protocol-specific
742 contains an example configuration for sending messages via some of the
743 well-known public mail providers;
744 note it also gives a compact overview on how to setup a secure SSL/TLS
748 Message recipients (as specified on the command line or defined in
753 may not only be email addressees but can also be names of mailboxes and
754 even complete shell command pipe specifications.
755 Proper (shell) quoting is necessary, e.g., to embed whitespace characters.
756 (Recall that \*(UA deals with mail standards, therefore those define the
757 rules with which content is interpreted.)
760 is not set then only network addresses (see
762 for a description of mail addresses) and plain user names (including MTA
763 aliases) may be used, other types will be filtered out, giving a warning
766 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
767 .\" grep the latter for the complete picture
771 is set then extended recipient addresses will optionally be accepted:
772 Any name which starts with a vertical bar
774 character specifies a command pipe \(en the command string following the
776 is executed and the message is sent to its standard input;
777 Likewise, any name that starts with the character slash
779 or the character sequence dot slash
781 is treated as a file, regardless of the remaining content.
782 Any other name which contains an at sign
784 character is treated as a network address;
785 Any other name which starts with a plus sign
787 character specifies a mailbox name;
788 Any other name which contains a slash
790 character but no exclamation mark
794 character before also specifies a mailbox name;
795 What remains is treated as a network address.
797 .Bd -literal -offset indent
798 $ echo bla | \*(ua -Sexpandaddr -s test ./mbox.mbox
799 $ echo bla | \*(ua -Sexpandaddr -s test '|cat >> ./mbox.mbox'
800 $ echo safe | LC_ALL=C \e
801 \*(ua -:/ -Sv15-compat -Ssendwait -Snosave \e
802 -Sexpandaddr=fail,-all,+addr -s test \e
807 It is possible to create personal distribution lists via the
809 command, so that, for instance, the user can send mail to
811 and have it go to a group of people:
814 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
817 Please note that this mechanism has nothing in common with the system
818 wide aliases that may be used by the local MTA (mail-transfer-agent),
819 which are subject to the
823 and are often tracked in a file
829 Personal aliases will be expanded by \*(UA before the message is sent,
830 and are thus a convenient alternative to specifying each addressee by
834 To avoid environmental noise scripts should
836 \*(UA from any configuration files and create a script-local
837 environment, ideally with the command line options
839 to disable any configuration file in conjunction with repititions of
841 to specify variables:
843 .Bd -literal -offset indent
844 $ env LC_ALL=C password=NOTSECRET \e
845 \*(ua -:/ -Sv15-compat -Ssendwait -Snosave \e
846 -Sexpandaddr=fail,-all,+addr \e
847 -S 'smtp=smtps://mylogin@some.host:465' -Ssmtp-auth=login \e
848 -S 'from=scriptreply@domain' \e
849 -s 'subject' -a attachment_file \e
850 -. "Recipient 1 <recipient1@domain>" recipient2@domain \e
855 In interactive mode, which is introduced in the next section, messages
856 can be sent by calling the
858 command with a list of recipient addresses \(em the semantics are
859 completely identical to non-interactive message sending, except that
860 it is likely necessary to separate recipient lists with commas:
862 .Bd -literal -offset indent
863 $ \*(ua -d -Squiet -Semptystart
864 "/var/spool/mail/user": 0 messages
865 ? mail "Recipient 1 <recipient1@domain>", recipient2@domain
866 ? # Will do the right thing (tm)
867 ? m recipient1@domain recipient2@domain
871 .\" .Ss "On reading mail, and interactive mode" {{{
872 .Ss "On reading mail, and interactive mode"
874 When invoked without addressees \*(UA enters interactive mode in which
876 When used like that the user's system mailbox (see the command
878 for an in-depth description of the different mailbox types that exist)
879 is read in and a one line header of each message therein is displayed.
880 The visual style of this summary of
882 can be adjusted through the variable
884 and the possible sorting criterion via
886 If the initially opened mailbox is empty \*(UA will instead exit
887 immediately (after displaying a message) unless the variable
896 will give a listing of all available commands and
898 will give a summary of some common ones.
899 If the \*(OPal documentation strings are available one can type
901 and see the actual expansion of
903 and what it's purpose is, i.e., commands can be abbreviated
904 (note that POSIX defines some abbreviations, so that the alphabetical
905 order of commands doesn't necessarily relate to the abbreviations; it is
906 possible to define overwrites with the
911 Messages are given numbers (starting at 1) which uniquely identify
912 messages; the current message \(en the
914 \(en will either be the first new message, or the first unread message,
915 or the first message of the mailbox; the option
917 will instead cause usage of the last message for this purpose.
922 ful of header summaries containing the
926 will display only the summaries of the given messages, defaulting to the
930 Messages can be displayed on the user's terminal with the
934 By default the current message
936 is displayed, but like with many other commands it is possible to give
937 a fancy message specification (see
938 .Sx "Specifying messages" ) ,
941 will display all unread messages,
946 will type the messages 1 and 5,
948 will type the messages 1 through 5, and
952 will display the last and the next message, respectively.
955 (a more substantial alias of the standard command
957 will display a header summary of the given message specification list
958 instead of their content, e.g., the following will search for subjects:
961 .Dl ? from """@Some subject to search for"""
964 In the default setup all header fields of a message will be displayed,
965 but this can be changed: either by blacklisting a list of fields via
967 or by whitelisting only a given list with the
970 .Ql Ic \:retain Ns \0date from to cc subject .
971 In order to display all header fields of a message regardless of
972 currently active ignore or retain lists, use the command
976 controls wether and when \*(UA will use the configured
978 for display instead of directly writing to the user terminal
979 (generally speaking).
980 Note that historically the global
982 not only adjusts the list of displayed headers, but also sets
986 Dependent upon the configuration a line editor (see the section
987 .Sx "On terminal control and line editor" )
988 aims at making user experience with the many
991 When reading the system mailbox or when
995 specified a mailbox explicitly prefixed with the special
997 modifier (propagating the mailbox to a primary one) then messages which
998 have been read will be moved to a secondary mailbox, the user's
1000 file, automatically when the mailbox is left, either by changing the
1001 active mailbox or by quitting \*(UA (also see
1002 .Sx "Message states" )
1003 \(en this automatic moving from a system or primary to the secondary
1004 mailbox is not performed when the variable
1009 After examining a message the user can also
1013 to the sender and all recipients or
1015 exclusively to the sender(s).
1016 Messages can also be
1018 ed (shorter alias is
1020 Note that when replying to or forwarding a message recipient addresses
1021 will be stripped from comments and names unless the option
1024 Deletion causes \*(UA to forget about the message;
1025 This is not irreversible, though, one can
1027 the message by giving its number,
1028 or the \*(UA session can be ended by giving the
1033 To end a mail processing session one may either issue
1035 to cause a full program exit, which possibly includes
1036 automatic moving of read messages to
1038 as well as updating the \*(OPal line editor
1042 instead in order to prevent any of these actions.
1045 .\" .Ss "HTML mail and MIME attachments" {{{
1046 .Ss "HTML mail and MIME attachments"
1048 Messages which are HTML-only get more and more common and of course many
1049 messages come bundled with a bouquet of MIME attachments.
1050 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1051 with HTML messages (see
1052 .Sx "The mime.types files" ) ,
1053 it normally can't deal with any of these itself, but instead programs
1054 need to become registered to deal with specific MIME types or file
1056 These programs may either prepare plain text versions of their input
1057 in order to enable \*(UA to display the content on the terminal,
1058 or display the content themselves, for example in a graphical window.
1061 To install an external handler program for a specific MIME type set an
1063 .Va pipe-TYPE/SUBTYPE
1064 variable; to instead define a handler for a specific file extension set
1067 variable \(en these handlers take precedence.
1068 \*(OPally \*(UA supports mail user agent configuration as defined in
1069 RFC 1524; this mechanism, documented in the section
1070 .Sx "The Mailcap files" ,
1071 will be queried for display or quote handlers if none of the former two
1072 .\" TODO v15-compat "will be" -> "is"
1073 did; it will be the sole source for handlers of other purpose.
1074 A last source for handlers may be the MIME type definition itself, if
1075 the \*(UA specific type-marker extension was used when defining the type
1078 (Many of the builtin MIME types do so by default.)
1082 .Va mime-counter-evidence
1083 can be set to improve dealing with faulty MIME part declarations as are
1084 often seen in real-life messages.
1085 E.g., to display a HTML message inline (that is, converted to a more
1086 fancy plain text representation than the builtin converter is capable to
1087 produce) with either of the text-mode browsers
1091 teach \*(UA about MathML documents and make it display them as plain
1092 text, and to open PDF attachments in an external PDF viewer,
1093 asynchronously and with some other magic attached:
1095 .Bd -literal -offset indent
1096 if $features !@ HTML-FILTER
1097 #set pipe-text/html="elinks -force-html -dump 1"
1098 set pipe-text/html="lynx -stdin -dump -force_html"
1099 # Display HTML as plain text instead
1100 #set pipe-text/html=@
1102 mimetype '@ application/mathml+xml mathml'
1103 set pipe-application/pdf="@&=@ \e
1104 trap \e"rm -f \e\e\e"${NAIL_FILENAME_TEMPORARY}\e\e\e"\e" EXIT;\e
1105 trap \e"trap \e\e\e"\e\e\e" INT QUIT TERM; exit 1\e" \e INT QUIT TERM;\e
1106 xpdf \e"${NAIL_FILENAME_TEMPORARY}\e""
1110 Note: special care must be taken when using such commands as mail
1111 viruses may be distributed by this method: if messages of type
1112 .Ql application/x-sh
1113 or files with the extension
1115 were blindly filtered through the shell, for example, a message sender
1116 could easily execute arbitrary code on the system \*(UA is running on.
1117 For more on MIME, also in respect to sending of messages, see the
1119 .Sx "The mime.types files" ,
1120 .Sx "The Mailcap files"
1125 .\" .Ss "Mailing lists" {{{
1128 \*(UA offers some support to ease handling of mailing lists.
1131 promotes all given arguments to known mailing lists, and
1133 sets their subscription attribute, creating them first as necessary.
1138 automatically, but only resets the subscription attribute.)
1139 Using the commands without arguments will show (a subset of) all
1140 currently defined mailing lists.
1145 can be used to mark out messages with configured list addresses
1146 in the header display.
1149 \*(OPally mailing lists may also be specified as (extended) regular
1150 expressions, which allows matching of many addresses with a single
1152 However, all fully qualified list addresses are matched via a fast
1153 dictionary, whereas expressions are placed in (a) list(s) which is
1154 (are) matched sequentially.
1156 .Bd -literal -offset indent
1157 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1158 mlist a1@b1.c1 a2@b2.c2 .*@lists.c3$
1159 mlsubscribe a4@b4.c4 exact@lists.c3
1164 .Va followup-to-honour
1166 .Ql Mail-\:Followup-\:To:
1167 header is honoured when the message is being replied to (via
1173 controls wether this header is created when sending mails; it will be
1174 created automatically for a couple of reasons, too, like when the
1176 .Dq mailing list specific
1181 is used to respond to a message with its
1182 .Ql Mail-Followup-To:
1186 A difference in between the handling of known and subscribed lists is
1187 that the address of the sender is usually not part of a generated
1188 .Ql Mail-Followup-To:
1189 when addressing the latter, whereas it is for the former kind of lists.
1190 Usually because there are exceptions: say, if multiple lists are
1191 addressed and not all of them are subscribed lists.
1193 For convenience \*(UA will, temporarily, automatically add a list
1194 address that is presented in the
1196 header of a message that is being responded to to the list of known
1198 Shall that header have existed \*(UA will instead, dependend on the
1200 .Va reply-to-honour ,
1203 for this purpose in order to accept a list administrators' wish that
1204 is supposed to have been manifested like that (but only if it provides
1205 a single address which resides on the same domain as what is stated in
1209 .\" .Ss "Resource files" {{{
1210 .Ss "Resource files"
1212 Upon startup \*(UA reads in several resource files:
1214 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1217 System wide initialization file.
1218 Reading of this file can be suppressed, either by using the
1222 command line options, or by setting the environment variable
1223 .Ev NAIL_NO_SYSTEM_RC .
1227 File giving initial commands.
1228 A different file can be chosen by setting the environment variable
1230 Reading of this file can be suppressed with the
1232 command line option.
1234 .It Va NAIL_EXTRA_RC
1235 Can be used to define an optional startup file to be read after all
1236 other resource files.
1237 It can be used to specify settings that are not understood by other
1239 implementations, for example.
1240 This variable is only honoured when defined in a resource file.
1244 The content of these files is interpreted as follows:
1247 .Bl -bullet -compact
1249 A lines' leading whitespace is removed.
1251 Empty lines are ignored.
1253 Any other line is interpreted as a command.
1254 It may be spread over multiple input lines if the newline character is
1256 by placing a backslash character
1258 as the last character of the line; whereas any leading whitespace of
1259 follow lines is ignored, trailing whitespace before a escaped newline
1260 remains in the input.
1262 If the line (content) starts with the number sign
1264 then it is a comment-command \(en a real command! \(en and also ignored.
1265 This command is the only form of comment that is understood.
1271 .Bd -literal -offset indent
1272 # This line is a comment command. And y\e
1273 es, it is really continued here.
1280 .\" .Ss "Character sets" {{{
1281 .Ss "Character sets"
1283 \*(OP \*(UA detects the character set of the terminal by using
1284 mechanisms that are controlled by the
1289 should give an overview); the \*(UA internal variable
1291 will be set to the detected terminal character set accordingly
1292 and will thus show up in the output of the commands
1298 However, a user supplied
1300 value is not overwritten by this detection mechanism: this
1302 must be used if the detection doesn't work properly,
1303 and it may be used to adjust the name of the locale character set.
1304 E.g., on BSD systems one may use a locale with the character set
1305 ISO8859-1, which is not a valid name for this character set; to be on
1306 the safe side, one may set
1308 to the correct name, which is ISO-8859-1.
1311 Note that changing the value doesn't mean much beside that,
1312 since several aspects of the real character set are implied by the
1313 locale environment of the system,
1314 and that stays unaffected by the content of an overwritten
1317 (This is mostly an issue when interactively using \*(UA, though.
1318 It is actually possible to send mail in a completely
1320 locale environment, an option that \*(UA's test-suite uses excessively.)
1323 If no character set conversion capabilities have been compiled into
1326 doesn't include the term
1330 will be the only supported character set,
1331 it is simply assumed that it can be used to exchange 8-bit messages,
1332 and the rest of this section does not apply;
1333 it may however still be necessary to explicitly set it if automatic
1334 detection fails, since in that case it defaults to the mentioned
1335 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1339 When reading messages, their text is converted into
1341 as necessary in order to display them on the users terminal.
1342 Unprintable characters and invalid byte sequences are detected
1343 and replaced by proper substitution characters (unless the variable
1345 was set once \*(UA was started).
1347 .Va charset-unknown-8bit
1348 to deal with another hairy aspect of message interpretation.
1351 When sending messages all their parts and attachments are classified.
1352 Whereas no character set conversion is performed on those parts which
1353 appear to be binary data,
1354 the character set being used must be declared within the MIME header of
1355 an outgoing text part if it contains characters that do not conform to
1356 the set of characters that are allowed by the email standards.
1357 Permissible values for character sets can be declared using the
1361 which defines a catch-all last-resort fallback character set that is
1362 implicitly appended to the list of character-sets in
1366 When replying to a message and the variable
1367 .Va reply-in-same-charset
1368 is set then the character set of the message being replied to is tried
1370 And it is also possible to make \*(UA work even more closely related to
1371 the current locale setting automatically by using the variable
1372 .Va sendcharsets-else-ttycharset ,
1373 please see there for more information.
1376 All the specified character sets are tried in order unless the
1377 conversion of the part or attachment succeeds.
1378 If none of the tried (8-bit) character sets is capable to represent the
1379 content of the part or attachment,
1380 then the message will not be sent and its text will optionally be
1384 In general, if the message
1385 .Dq Cannot convert from a to b
1386 appears, either some characters are not appropriate for the currently
1387 selected (terminal) character set,
1388 or the needed conversion is not supported by the system.
1389 In the first case, it is necessary to set an appropriate
1391 locale and/or the variable
1395 The best results are usually achieved when \*(UA is run in a UTF-8
1396 locale on a UTF-8 capable terminal, in which case the full Unicode
1397 spectrum of characters is available.
1398 In this setup characters from various countries can be displayed,
1399 while it is still possible to use more simple character sets for sending
1400 to retain maximum compatibility with older mail clients.
1403 On the other hand the POSIX standard defines a locale-independent 7-bit
1404 .Dq portable character set
1405 that should be used when overall portability is an issue, the even more
1406 restricted subset named
1407 .Dq portable filename character set
1408 consisting of A-Z, a-z, 0-9, period
1417 .\" .Ss "Message states" {{{
1418 .Ss "Message states"
1420 \*(UA differentiates in between several different message states;
1421 the current state will be reflected in header summary displays if
1423 is configured to do so (via the internal variable
1425 and messages can also be selected and be acted upon depending on their
1427 .Sx "Specifying messages" ) .
1428 When operating on the system mailbox or in primary mailboxes opened with
1433 special actions, like the automatic moving of messages to the secondary
1435 mailbox may be applied when the mailbox is left (also implicitly via
1436 a successful exit of \*(UA, but not if the special command
1438 is used) \(en however, because this may be irritating to users which
1441 mail-user-agents, the default global
1447 variables in order to suppress this behaviour.
1449 .Bl -tag -width ".It Ql _reserved"
1451 Message has neither been viewed nor moved to any other state.
1452 Such messages are retained even in the system mailbox.
1455 Message has neither been viewed nor moved to any other state, but the
1456 message was present already when the mailbox has been opened last:
1457 Such messages are retained even in the system mailbox.
1460 The message has been processed by one of the following commands:
1480 commands may also cause the next message to be marked as read, depending
1486 command is used, messages that are in the system mailbox or in mailboxes
1487 which were opened with the special
1491 state when the mailbox is left will be saved in
1498 The message has been processed by one of the following commands:
1504 can be used to access such messages.
1507 The message has been processed by a
1509 command and it will be retained in its current location.
1512 The message has been processed by one of the following commands:
1518 command is used, messages that are in the system mailbox or in mailboxes
1519 which were opened with the special
1523 state when the mailbox is left will be deleted; they will be saved in
1531 .\" .Ss "Specifying messages" {{{
1532 .Ss "Specifying messages"
1539 can be given a list of message numbers as arguments to apply to a number
1540 of messages at once.
1543 deletes messages 1 and 2,
1546 will delete the messages 1 through 5.
1547 In sorted or threaded mode (see the
1551 will delete the messages that are located between (and including)
1552 messages 1 through 5 in the sorted/threaded order, as shown in the
1555 Multiple colon modifiers can be joined into one, e.g.,
1557 The following special message names exist:
1559 .Bl -tag -width ".It Ar _n_u"
1565 All old messages (any not in state
1590 All answered messages
1595 All messages marked as draft.
1597 \*(OP All messages classified as spam.
1599 \*(OP All messages with unsure spam classification.
1601 The current message, the so-called
1604 The message that was previously the current message.
1606 The parent message of the current message,
1607 that is the message with the Message-ID given in the
1609 field or the last entry of the
1611 field of the current message.
1613 The next previous undeleted message,
1614 or the next previous deleted message for the
1617 In sorted/threaded mode,
1618 the next previous such message in the sorted/threaded order.
1620 The next undeleted message,
1621 or the next deleted message for the
1624 In sorted/threaded mode,
1625 the next such message in the sorted/threaded order.
1627 The first undeleted message,
1628 or the first deleted message for the
1631 In sorted/threaded mode,
1632 the first such message in the sorted/threaded order.
1635 In sorted/threaded mode,
1636 the last message in the sorted/threaded order.
1640 selects the message addressed with
1644 is any other message specification,
1645 and all messages from the thread that begins at it.
1646 Otherwise it is identical to
1651 the thread beginning with the current message is selected.
1656 All messages that were included in the message list for the previous
1659 .It Ar / Ns Ar string
1660 All messages that contain
1662 in the subject field (case ignored).
1669 the string from the previous specification of that type is used again.
1671 .It Xo Op Ar @ Ns Ar name-list Ns
1674 All messages that contain the given case-insensitive search
1676 ession; if the \*(OPal regular expression (see
1678 support is available
1680 will be interpreted as (an extended) one if any of the
1682 (extended) regular expression characters is seen.
1684 .Ar @ Ns Ar name-list
1685 part is missing, the search is restricted to the subject field body,
1688 specifies a comma-separated list of header fields to search, as in
1690 .Dl '@to,from,cc@Someone i ought to know'
1692 In order to search for a string that includes a
1694 (commercial at) character the
1696 is effectively non-optional, but may be given as the empty string.
1697 Some special header fields may be abbreviated:
1711 respectively and case-insensitively.
1716 can be used to search in (all of) the header(s) of the message, and the
1725 can be used to perform full text searches \(en whereas the former
1726 searches only the body, the latter also searches the message header.
1728 This message specification performs full text comparison, but even with
1729 regular expression support it is almost impossible to write a search
1730 expression that savely matches only a specific address domain.
1731 To request that the content of the header is treated as a list of
1732 addresses, and to strip those down to the plain email address which the
1733 search expression is to be matched against, prefix the header name
1734 (abbreviation) with a tilde
1737 .Dl @~f@@a\e.safe\e.domain\e.match$
1741 .Dq any substring matches
1744 header, which will match addresses (too) even if
1746 is set (and POSIX says
1747 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1750 variable is set, only the local part of the address is evaluated
1751 for the comparison, not ignoring case, and the setting of
1753 is completely ignored.
1754 For finer control and match boundaries use the
1756 search expression; the \*(OPal IMAP-style
1758 expression can also be used if substring matches are desired.
1762 \*(OP IMAP-style SEARCH expressions may also be used.
1763 This addressing mode is available with all types of folders;
1764 \*(UA will perform the search locally as necessary.
1765 Strings must be enclosed by double quotes
1767 in their entirety if they contain white space or parentheses;
1768 within the quotes, only backslash
1770 is recognized as an escape character.
1771 All string searches are case-insensitive.
1772 When the description indicates that the
1774 representation of an address field is used,
1775 this means that the search string is checked against both a list
1778 .Bd -literal -offset indent
1779 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1784 and the addresses without real names from the respective header field.
1785 These search expressions can be nested using parentheses, see below for
1789 .Bl -tag -compact -width ".It Ar _n_u"
1790 .It Ar ( criterion )
1791 All messages that satisfy the given
1793 .It Ar ( criterion1 criterion2 ... criterionN )
1794 All messages that satisfy all of the given criteria.
1796 .It Ar ( or criterion1 criterion2 )
1797 All messages that satisfy either
1802 To connect more than two criteria using
1804 specifications have to be nested using additional parentheses,
1806 .Ql (or a (or b c)) ,
1810 .Ql ((a or b) and c) .
1813 operation of independent criteria on the lowest nesting level,
1814 it is possible to achieve similar effects by using three separate
1818 .It Ar ( not criterion )
1819 All messages that do not satisfy
1821 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1822 All messages that contain
1824 in the envelope representation of the
1827 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1828 All messages that contain
1830 in the envelope representation of the
1833 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1834 All messages that contain
1836 in the envelope representation of the
1839 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1840 All messages that contain
1845 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1846 All messages that contain
1848 in the envelope representation of the
1851 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1852 All messages that contain
1857 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1858 All messages that contain
1861 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1862 All messages that contain
1864 in their header or body.
1865 .It Ar ( larger size )
1866 All messages that are larger than
1869 .It Ar ( smaller size )
1870 All messages that are smaller than
1874 .It Ar ( before date )
1875 All messages that were received before
1877 which must be in the form
1881 denotes the day of the month as one or two digits,
1883 is the name of the month \(en one of
1884 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1887 is the year as four digits, e.g.,
1891 All messages that were received on the specified date.
1892 .It Ar ( since date )
1893 All messages that were received since the specified date.
1894 .It Ar ( sentbefore date )
1895 All messages that were sent on the specified date.
1896 .It Ar ( senton date )
1897 All messages that were sent on the specified date.
1898 .It Ar ( sentsince date )
1899 All messages that were sent since the specified date.
1901 The same criterion as for the previous search.
1902 This specification cannot be used as part of another criterion.
1903 If the previous command line contained more than one independent
1904 criterion then the last of those criteria is used.
1908 .\" .Ss "On URL syntax and credential lookup" {{{
1909 .Ss "On URL syntax and credential lookup"
1911 \*(IN For accessing protocol-specific resources usage of Uniform
1912 Resource Locators (URL, RFC 1738) has become omnipresent.
1913 \*(UA expects and understands URLs in the following form;
1916 denote optional parts, optional either because there also exist other
1917 ways to define the information in question or because support of the
1918 part is protocol-specific (e.g.,
1920 is used by the IMAP protocol but not by POP3);
1925 are specified they must be given in URL percent encoded form (RFC 3986;
1933 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1936 Note that these \*(UA URLs most often don't conform to any real
1937 standard, but instead represent a normalized variant of RFC 1738 \(en
1938 they are not used in data exchange but only ment as a compact,
1939 easy-to-use way of defining and representing information in
1940 a well-known notation.
1943 Many internal variables of \*(UA exist in multiple versions, called
1944 variable chains for the rest of this document: the plain
1949 .Ql variable-USER@HOST .
1956 had been specified in the respective URL, otherwise it refers to the plain
1962 that had been found when doing the user chain lookup as is described
1965 will never be in URL percent encoded form, wether it came from an URL or
1966 not; i.e., values of
1967 .Sx "INTERNAL VARIABLES"
1968 must not be URL percent encoded.
1971 For example, wether an hypothetical URL
1972 .Ql smtp://hey%3Ayou@our.house
1973 had been given that includes a user, or wether the URL was
1974 .Ql smtp://our.house
1975 and the user had been found differently, to lookup the variable chain
1976 .Va smtp-use-starttls
1977 \*(UA first looks for wether
1978 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1979 is defined, then wether
1980 .Ql smtp-\:use-\:starttls-\:our.house
1981 exists before finally ending up looking at the plain variable itself.
1984 \*(UA obeys the following logic scheme when dealing with the
1985 necessary credential informations of an account:
1991 has been given in the URL the variables
1995 are looked up; if no such variable(s) can be found then \*(UA will,
1996 when enforced by the \*(OPal variables
1997 .Va netrc-lookup-HOST
2004 specific entry which provides a
2006 name: this lookup will only succeed if unambiguous (one possible matching
2010 If there is still no
2012 then \*(UA will fall back to the user who is supposed to run \*(UA:
2013 either the name that has been given with the
2015 command line option (or, equivalently, but with less precedence, the
2016 environment variable
2021 The identity of this user has been fixated during \*(UA startup and is
2022 known to be a valid user on the current host.
2025 Authentication: unless otherwise noted this will lookup the
2026 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
2027 variable chain, falling back to a protocol-specific default should this
2033 has been given in the URL, then if the
2035 has been found through the \*(OPal
2037 then that may have already provided the password, too.
2038 Otherwise the variable chain
2039 .Va password-USER@HOST , password-HOST , password
2040 is looked up and used if existent.
2042 \*(OP Then if any of the variables of the chain
2043 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2045 is set the shell command specified therein is run and the output (less
2046 newline characters) will be used as the password.
2047 It is perfectly valid for such an agent to simply not return any data,
2048 in which case the password lookup is continued somewhere else;
2049 Any command failure is treated as a hard error, however.
2051 Afterwards the complete \*(OPal variable chain
2052 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2056 cache is searched for a password only (multiple user accounts for
2057 a single machine may exist as well as a fallback entry without user
2058 but with a password).
2060 If at that point there is still no password available, but the
2061 (protocols') chosen authentication type requires a password, then in
2062 interactive mode the user will be prompted on the terminal.
2067 S/MIME verification works relative to the values found in the
2071 header field(s), which means that the values of
2072 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2074 .Va smime-sign-message-digest
2075 will not be looked up using the
2079 chains from above but instead use the corresponding values from the
2080 message that is being worked on.
2081 In unusual cases multiple and different
2085 combinations may therefore be involved \(en on the other hand those
2086 unusual cases become possible.
2087 The usual case is as short as:
2090 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2091 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2096 contains complete example configurations.
2099 .\" .Ss "On terminal control and line editor" {{{
2100 .Ss "On terminal control and line editor"
2102 \*(OP \*(UA can be configured to support a line editor,
2103 history lists that can be saved in between sessions,
2104 and terminal control to improve interactive usage experience.
2105 For the former one may either link against an external library
2106 .Pf ( Xr readline 3 ;
2107 behaviour of \*(UA may differ slightly),
2108 or enable the builtin Mailx-Line-Editor (MLE), which should work in all
2109 environments which comply to the ISO C standard
2111 and which will support wide glyphs if possible (the necessary
2112 functionality had been removed from ISO C, but was included in
2114 Prevent usage of a line editor in interactive mode by setting the
2116 .Va line-editor-disable .
2121 feature is available then input from line editor prompts will be saved
2122 in a history list that can be searched in and be expanded from.
2123 Such saving can be prevented by prefixing input with any amount of
2125 Aspects of history, like allowed content, maximum size etc., can be
2126 configured with the variables
2129 .Va history-gabby-persist
2134 \*(OP Terminal control will be realized through one of the standard
2136 libraries, either the
2138 or, alternatively, the
2140 both of which will be initialized to work with the environment variable
2142 Terminal control will enhance or enable interactive usage aspects, e.g.,
2143 .Sx "Coloured display" ,
2144 and extend behaviour of the MLE, which may learn the key-sequences of
2145 keys like the cursor and function keys, and which will automatically
2148 alternative screen shall the terminal support it.
2149 The internal variable
2151 can be used to overwrite settings or to learn (correct(ed)) keycodes.
2152 Actual interaction with the chosen library can be disabled completely by
2153 setting the internal variable
2154 .Va termcap-disable ,
2155 which may be necessary for proper operation on the actual terminal;
2157 will be queried regardless, even if the \*(OPal support for the
2158 libraries has not been enabled at configuration time.
2161 \*(OP The builtin \*(UA line editor MLE supports the following
2162 operations; the notation
2164 stands for the combination of the
2166 key plus the mentioned character, e.g.,
2169 .Dq hold down control key and press the A key .
2170 Especially without termcap support setting respective entries in
2172 will help shall the MLE misbehave.
2173 The MLE also supports several
2178 .Bl -tag -compact -width "Ql _M"
2180 Go to the start of the line.
2182 Move the cursor backward one character.
2184 Forward delete the character under the cursor;
2185 quits \*(UA if used on the empty line unless the
2189 Go to the end of the line.
2191 Move the cursor forward one character.
2194 Cancel current operation, full reset.
2195 If there is an active history search or tabulator expansion then this
2196 command will first reset that, reverting to the former line content;
2197 thus a second reset is needed for a full reset in this case.
2198 In all cases \*(UA will reset a possibly used multibyte character input
2204 backward delete one character.
2208 .Dq horizontal tabulator :
2209 try to expand the word before the cursor.
2211 .Dq tabulator-completion
2212 as is known from the
2214 but really means the usual \*(UA expansion, as documented for
2216 yet it involves shell expansion as a last step, too.)
2221 complete this line of input.
2223 Delete all characters from the cursor to the end of the line.
2227 \*(OP Go to the next history entry.
2232 \*(OP Go to the previous history entry.
2234 \*(OP Complete the current line from (the remaining older) history entries.
2241 Prompts for a Unicode character to be inserted.
2243 Delete the characters from the one preceding the cursor to the preceding
2246 Move the cursor forward one word boundary.
2248 Move the cursor backward one word boundary.
2252 If the keycodes are known then the left and right cursor keys will map to
2256 respectively, the up and down cursor keys will map to
2260 and the Home/End/PgUp/PgDown keys will call the
2262 command with the respective arguments
2268 (i.e., perform scrolling through the header summary list).
2269 Also the up and down cursor keys should invoke
2271 for up- and downwards movement if they are used while the
2276 .\" .Ss "Coloured display" {{{
2277 .Ss "Coloured display"
2279 \*(OP \*(UA can be configured to support a coloured display and font
2280 attributes by emitting ANSI / ISO 6429 SGR (select graphic rendition)
2282 Usage of colours and font attributes solely depends upon the
2283 capability of the detected terminal type that is defined by the
2284 environment variable
2286 and which can be fine-tuned by the user via the internal variable
2290 On top of what \*(UA knows about the terminal the boolean variable
2292 defines wether the actually applicable colour and font attribute
2293 sequences should also be generated when output is going to be paged
2294 through the external program defined by the environment variable
2299 This is not enabled by default because different pager programs need
2300 different command line switches or other configuration in order to
2301 support those sequences.
2302 \*(UA however knows about some widely used pagers and in a clean
2303 environment it is often enough to simply set
2305 please refer to that variable for more on this topic.
2310 is set then any active usage of colour and font attribute sequences
2311 is suppressed, but without affecting possibly established
2316 To define and control colours and font attributes a single multiplexer
2317 command family exists:
2319 shows or defines colour mappings for the given colour type (e.g.,
2322 can be used to remove mappings of a given colour type.
2323 Since colours are only available in interactive mode, it may make
2324 sense to conditionalize the colour setup by encapsulating it with
2327 .Bd -literal -offset indent
2328 if terminal && $features =@ +colour
2329 colour iso view-msginfo ft=bold,fg=green
2330 colour iso view-header ft=bold,fg=red "from,subject"
2331 colour iso view-header fg=red
2333 uncolour iso view-header from,subject
2334 colour iso view-header ft=bold,fg=magenta,bg=cyan
2335 colour 256 view-header ft=bold,fg=208,bg=230 subject,from
2336 colour mono view-header ft=bold
2337 colour mono view-header ft=bold,ft=reverse subject,from
2341 .\" }}} (DESCRIPTION)
2344 .\" .Sh COMMANDS {{{
2347 Each command is typed on a line by itself,
2348 and may take arguments following the command word.
2349 The command need not be typed in its entirety \(en
2350 the first command which matches the typed prefix is used.
2351 An \(en alphabetically \(en sorted list of commands can be shown
2358 when given an argument, will show a documentation string for the
2359 command matching the expanded argument, as in
2361 which should be a shorthand of
2363 documentation strings are however \*(OPal.
2366 For commands which take message lists as arguments, the next message
2367 forward that satisfies the command's requirements will be used shall no
2368 explicit message list have been specified.
2369 If there are no messages forward of the current message,
2370 the search proceeds backwards,
2371 and if there are no good messages at all,
2373 .Dq no applicable messages
2374 and aborts the command.
2375 The arguments to commands can be quoted, using the following methods:
2378 .Bl -bullet -compact -offset indent
2380 An argument can be enclosed between paired double-quotes
2385 any white space, shell word expansion, or backslash characters (except
2386 as described next) within the quotes are treated literally as part of
2388 A double-quote will be treated literally within single-quotes and vice
2390 Inside such a quoted string the actually used quote character can be
2391 used nonetheless by escaping it with a backslash
2397 An argument that is not enclosed in quotes, as above, can usually still
2398 contain space characters if those spaces are backslash-escaped, as in
2402 A backslash outside of the enclosing quotes is discarded
2403 and the following character is treated literally as part of the argument.
2406 An unquoted backslash at the end of a command line is discarded and the
2407 next line continues the command.
2411 Filenames, where expected, are subsequently subjected to the following
2412 transformations, in sequence:
2415 .Bl -bullet -compact -offset indent
2417 If the filename begins with an unquoted plus sign, and the
2419 variable is defined,
2420 the plus sign will be replaced by the value of the
2422 variable followed by a slash.
2425 variable is unset or is set to null, the filename will be unchanged.
2428 Shell word expansions are applied to the filename.
2429 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2430 .Sy Compatibility note:
2431 on the long run support for complete shell word expansion will be
2432 replaced by an internally implemented restricted expansion mechanism in
2433 order to circumvent possible security impacts through shell expansion.
2434 Expect that a growing number of program parts only support this
2437 Meta expansions are applied to the filename: leading tilde characters
2439 will be replaced by the expansion of
2441 and any occurrence of
2445 will be replaced by the expansion of the variable, if possible;
2446 \*(UA internal as well as environmental (shell) variables can be
2447 accessed through this mechanism.
2448 In order to include a raw
2450 character precede it with a backslash
2452 to include a backslash double it.
2453 If more than a single pathname results from this expansion and the
2454 command is expecting one file, an error results.
2456 Note that in interactive display context, in order to allow simple
2457 value acceptance (typing
2459 backslash quoting is performed automatically as necessary, e.g., a file
2460 .Ql diet\e is \ecurd.txt
2461 will be displayed as
2462 .Ql diet\e\e is \e\ecurd.txt .
2466 The following commands are available:
2468 .Bl -tag -width ".Ic _ccount"
2475 ) command which follows.
2479 The comment-command causes the entire line to be ignored.
2481 this really is a normal command which' purpose is to discard its
2484 indicating special character, which means that, e.g., trailing comments
2485 on a line are not possible.
2489 Goes to the next message in sequence and types it
2495 Display the preceding message, or the n'th previous message if given
2496 a numeric argument n.
2500 Show the current message number (the
2505 Show a brief summary of commands.
2506 \*(OP Given an argument a synopsis for the command in question is
2507 shown instead; commands can be abbreviated in general and this command
2508 can be used to see the full expansion of an abbreviation including the
2509 synopsis, try, e.g.,
2514 and see how the output changes.
2524 Interprets the remainder of the word as a macro name and passes it
2529 is a shorter synonym for
2530 .Ql call Ar mymacro .
2534 (ac) Creates, selects or lists (an) account(s).
2535 An account is a group of commands and variable settings which together
2536 usually arrange the environment for the purpose of creating a system login.
2537 Without any argument a listing of all defined accounts and their content
2539 A specific account can be activated by giving solely its name, resulting
2540 in the system mailbox or inbox of that account to be activated as via an
2541 explicit use of the command
2543 The two argument form is identical to defining a macro as via
2546 .Bd -literal -offset indent
2550 set from="myname@myisp.example (My Name)"
2551 set smtp=smtp://mylogin@smtp.myisp.example
2555 creates an account named
2557 which can later be selected by specifying
2561 (case-insensitive) always exists.
2563 are enabled by default and localize account settings \(en different to
2564 normal macros the settings will be reverted once the account is switched off.
2565 Accounts can be deleted via
2570 (a) With no arguments, shows all currently-defined aliases.
2571 With one argument, shows that alias.
2572 With more than one argument,
2573 creates a new alias or appends to an existing one.
2575 can be used to delete aliases.
2579 (alt) Manage a list of alternate addresses / names of the active user,
2580 members of which will be removed from recipient lists when replying to
2583 variable is not set).
2584 If arguments are given the set of alternate names is replaced by them,
2585 without arguments the current set is displayed.
2589 Takes a message list and marks each message as having been answered.
2590 This mark has no technical meaning in the mail system;
2591 it just causes messages to be marked in the header summary,
2592 and makes them specially addressable.
2596 Calls a macro that has been created via
2601 (ch) Change the working directory to
2603 or the given argument.
2609 \*(OP Only applicable to S/MIME signed messages.
2610 Takes a message list and a file name and saves the certificates
2611 contained within the message signatures to the named file in both
2612 human-readable and PEM format.
2613 The certificates can later be used to send encrypted messages to the
2614 respective message senders by setting
2615 .Va smime-encrypt-USER@HOST
2620 (ch) Change the working directory to
2622 or the given argument.
2628 Only applicable to threaded mode.
2629 Takes a message list and makes all replies to these messages invisible
2630 in header summaries, unless they are in state
2636 \*(OP Manage colour mappings for the type of colour given as the
2637 (case-insensitive) first argument, which must be one of
2639 for 256-colour terminals,
2644 for the standard 8-colour ANSI / ISO 6429 color palette and
2648 for monochrome terminals.
2649 Monochrome terminals cannot deal with colours, but only (some) font
2653 Without further arguments the list of all currently defined mappings
2654 for the given colour type is shown (as a special case giving
2658 will iterate over all types in order).
2659 Otherwise the second argument defines the mappable slot, the third
2660 argument a (comma-separated list of) colour and font attribute
2661 specification(s), and the optional fourth argument can be used to
2662 specify a precondition: if conditioned mappings exist they are tested in
2663 (creation) order unless a (case-insensitive) match has been found, and
2664 the default mapping (if any has been established) will only be chosen as
2666 The types of precondition available depend on the mappable slot, the
2667 following of which exist:
2670 Mappings prefixed with
2672 are used for the \*(OPal builtin Mailx-Line-Editor (MLE, see
2673 .Sx "On terminal control and line editor" )
2674 and don't support preconditions.
2676 .Bl -tag -compact -width view-partinfo
2678 This mapping is used for the position indicator that is visible when
2679 a line cannot be fully displayed on the screen.
2686 Mappings prefixed with
2688 are used in header summaries, and they all understand the preconditions
2690 (the current message) and
2692 for elder messages (only honoured in conjunction with
2693 .Va datefield-markout-older ) .
2695 .Bl -tag -compact -width view-partinfo
2697 This mapping is used for the
2699 that can be created with the
2703 formats of the variable
2706 For the complete header summary line except the
2708 and the thread structure.
2710 For the thread structure which can be created with the
2712 format of the variable
2717 Mappings prefixed with
2719 are used when displaying messages.
2721 .Bl -tag -compact -width view-partinfo
2723 This mapping is used for so-called
2725 lines, which are MBOX file format specific header lines.
2728 A comma-separated list of headers to which the mapping applies may be
2729 given as a precondition; if the \*(OPal regular expression support is
2730 available then if any of the
2732 (extended) regular expression characters is seen the precondition will
2733 be evaluated as (an extended) one.
2735 For the introductional message info line.
2736 .It Cd view-partinfo
2737 For MIME part info lines.
2741 The following (case-insensitive) colour definitions and font attributes
2742 are understood, multiple of which can be specified in a comma-separated
2752 It is possible (and often applicable) to specify multiple font
2753 attributes for a single mapping.
2756 foreground colour attribute:
2766 To specify a 256-color mode a decimal number colour specification in
2767 the range 0 to 255, inclusive, is supported, and interpreted as follows:
2769 .Bl -tag -compact -width "999 - 999"
2771 the standard ISO 6429 colors, as above.
2773 high intensity variants of the standard colors.
2775 216 colors in tuples of 6.
2777 grayscale from black to white in 24 steps.
2779 .Bd -literal -offset indent
2781 fg() { printf "\e033[38;5;${1}m($1)"; }
2782 bg() { printf "\e033[48;5;${1}m($1)"; }
2784 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
2785 printf "\e033[0m\en"
2787 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
2788 printf "\e033[0m\en"
2792 background colour attribute (see
2794 for possible values).
2798 Mappings may be removed with the command
2800 For a generic overview see the section
2801 .Sx "Coloured display" .
2806 (C) Copy messages to files whose names are derived from the author of
2807 the respective message and don't mark them as being saved;
2808 otherwise identical to
2813 (c) Copy messages to the named file and don't mark them as being saved;
2814 otherwise identical to
2819 With no arguments, shows all currently-defined custom headers.
2820 With one argument, shows that custom header.
2821 With more than one argument, creates a new or replaces an existing
2822 custom header with the name given as the first argument, the content of
2823 which being defined by the concatenated remaining arguments.
2825 can be used to delete custom headers.
2826 \*(ID Overwriting of automatically managed headers is neither supported
2828 Defined custom headers will be injected into newly composed or forwarded
2831 .Dl customhdr OpenPGP id=12345678; url=http://www.YYY.ZZ
2835 may also be used to inject custom headers; it is covered by
2840 Show the name of the current working directory.
2844 \*(OP For unencrypted messages this command is identical to
2846 Encrypted messages are first decrypted, if possible, and then copied.
2850 \*(OP For unencrypted messages this command is identical to
2852 Encrypted messages are first decrypted, if possible, and then copied.
2856 Without arguments the current list of macros, including their content,
2857 is shown, otherwise a macro is defined.
2858 A macro definition is a sequence of commands in the following form:
2859 .Bd -literal -offset indent
2868 A defined macro can be invoked explicitly by using the
2872 commands, or implicitly if a macro hook is triggered, e.g., a
2874 Note that interpretation of
2876 depends on how (i.e.,
2878 normal macro, folder hook, hook, account switch) the macro is invoked.
2879 Macros can be deleted via
2883 Macro behaviour, including option localization, will change in v15.
2884 Please be aware of that and possibly embed a version check in a resource
2889 (d) Marks the given message list as
2891 Deleted messages will neither be saved in
2893 nor will they be available for most other commands.
2905 Deletes the current message and displays the next message.
2906 If there is no next message, \*(UA says
2913 up or down by one message when given
2917 argument, respectively.
2921 Takes a message list and marks each given message as a draft.
2922 This mark has no technical meaning in the mail system;
2923 it just causes messages to be marked in the header summary,
2924 and makes them specially addressable.
2928 (ec) Echoes its arguments,
2929 resolving special names as documented for the command
2931 The escape sequences
2943 are interpreted just as they are by
2945 (proper quoting provided).
2949 (e) Point the text editor (as defined in
2951 at each message from the given list in turn.
2952 Modified contents are discarded unless the
2959 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2960 conditional \(em if the condition of a preceeding
2962 was false, check the following condition and execute the following block
2963 if it evaluates true.
2968 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2969 conditional \(em if none of the conditions of the preceeding
2973 commands was true, the
2979 (en) Marks the end of an
2980 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2981 conditional execution block.
2985 \*(OP Since \*(UA uses the console as a user interface it can happen
2986 that messages scroll by too fast to become recognized.
2987 Optionally an error message ring queue is available which stores
2988 duplicates of any error message and notifies the user in interactive
2989 sessions whenever a new error has occurred.
2990 The queue is finite: if its maximum size is reached any new message
2991 replaces the eldest.
2994 can be used to manage this message queue: if given
2996 or no argument the queue will be displayed and cleared,
2998 will only clear all messages from the queue.
3002 (ex or x) Exit from \*(UA without changing the active mailbox and skip
3003 any saving of messages in
3005 as well as a possibly tracked line editor history file.
3009 Show the list of features that have been compiled into \*(UA.
3010 (Outputs the contents of the variable
3017 but open the mailbox readonly.
3021 (fi) The file command switches to a new mailbox.
3022 Without arguments it shows status information of the current mailbox.
3023 If an argument is given, it will write out changes (such as deletions)
3024 the user has made and open a new mailbox.
3025 Some special conventions are recognized for the
3029 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
3031 (number sign) means the previous file,
3033 (percent sign) means the invoking user's system mailbox,
3035 means the system mailbox of
3037 (and never the value of
3039 regardless of its actual setting),
3041 (ampersand) means the invoking user's
3051 expands to the same value as
3053 but the file is handled as a system mailbox by, e.g., the
3057 commands, meaning that messages that have been read in the current
3058 session will be moved to the
3060 mailbox instead of simply being flagged as read.
3063 If the name matches one of the strings defined with the command
3065 it is replaced by its long form and expanded.
3066 If the name ends with
3071 it is treated as being compressed with
3076 respectively, and transparently handled through an intermediate
3077 (un)compression step (using a temporary file) with the according
3078 facility, sufficient support provided.
3079 Likewise, if the named file doesn't exist, but a file with one of the
3080 mentioned compression extensions does, then the name is automatically
3081 expanded and the compressed file is used.
3083 Otherwise, if the name ends with an extension for which
3084 .Va file-hook-load-EXTENSION
3086 .Va file-hook-save-EXTENSION
3087 variables are set, then the given hooks will be used to load and save
3089 and \*(UA will work with an intermediate temporary file.
3091 MBOX files (flat file-based mailboxes) are generally locked during file
3092 operations in order to avoid inconsistencies due to concurrent
3094 \*(OPal Mailbox files which \*(UA treats as system or primary mailboxes
3095 will also be protected by so-called dotlock files, the traditional way
3096 of mail spool file locking: for any file
3100 will be created for the duration of the synchronization \(em
3101 as necessary a privilege-separated dotlock child process will be used
3102 to accommodate for necessary privilege adjustments in order to create
3103 the dotlock file in the same directory
3104 and with the same user and group identities as the file of interest.
3107 for fine-tuning the handling of MBOX files.
3111 refers to a directory with the subdirectories
3116 then it is treated as a folder in
3121 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3122 .Dl \*(OU protocol://[user@]host[:port][/path]
3124 is taken as an Internet mailbox specification.
3125 The \*(OPally supported protocols are
3129 (POP3 with SSL/TLS encrypted transport).
3132 part is valid only for IMAP; there it defaults to
3134 Also see the section
3135 .Sx "On URL syntax and credential lookup" .
3139 contains special characters, in particular
3143 they must be escaped in URL notation \(en the command
3145 can be used to show the necessary conversion.
3149 Takes a message list and marks the messages as
3151 ged for urgent/special attention.
3152 This mark has no technical meaning in the mail system;
3153 it just causes messages to be highlighted in the header summary,
3154 and makes them specially addressable.
3163 With no arguments, list the names of the folders in the folder directory.
3164 With an existing folder as an argument,
3165 lists the names of folders below the named folder.
3171 but saves the message in a file named after the local part of the first
3172 recipient's address (instead of in
3179 but saves the message in a file named after the local part of the first
3180 recipient's address (instead of in
3187 but responds to all recipients regardless of the
3192 .It Ic followupsender
3195 but responds to the sender only regardless of the
3211 (f) Takes a list of message specifications and displays a summary of
3212 their message headers, as via
3214 An alias of this command is
3217 .Sx "Specifying messages" .
3223 but saves the message in a file named after the local part of the
3224 recipient's address (instead of in
3229 Takes a message and the address of a recipient
3230 and forwards the message to him.
3231 The text of the original message is included in the new one,
3232 with the value of the
3234 variable preceding it.
3239 commands specify which header fields are included in the new message.
3240 Only the first part of a multipart message is included unless the
3241 .Va forward-as-attachment
3245 is set recipient addresses will be stripped from comments, names etc.
3249 Specifies which header fields are to be ignored with the command
3251 This command has no effect when the
3252 .Va forward-as-attachment
3257 Specifies which header fields are to be retained with the command
3262 This command has no effect when the
3263 .Va forward-as-attachment
3268 Define or list command aliases, so-called ghosts.
3269 Without arguments a list of all currently known aliases is shown.
3270 With one argument the expansion of the given alias is shown.
3271 With two or more arguments a command alias is defined or updated: the
3272 first argument is the name under which the remaining command line should
3273 be accessible, the content of which can be just about anything.
3274 A ghost can be used everywhere a normal command can be used, but always
3275 takes precedence; any arguments that are given to the command alias are
3276 joined onto the alias content, and the resulting string forms the
3277 command line that is, in effect, executed.
3280 .Bd -literal -offset indent
3282 `ghost': no such alias: "xx"
3285 ghost xx "echo hello,"
3294 (h) Show the current group of headers, the size of which depends on
3297 and the style of which can be adjusted with the variable
3299 If a message-specification is given the group of headers containing the
3300 first message therein is shown and the message at the top of the screen
3315 the list of history entries;
3318 argument selects and shows the respective history entry \(en
3321 to accept it, and the history entry will become the new history top.
3322 The default mode if no arguments are given is
3329 Takes a message list and marks each message therein to be saved in the
3330 user's system mailbox instead of in
3332 Does not override the
3335 \*(UA deviates from the POSIX standard with this command, because a
3337 command issued after
3339 will display the following message, not the current one.
3344 (i) Part of the nestable
3345 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3346 conditional execution construct \(em if the given condition is true then
3347 the encapsulated block is executed.
3348 POSIX only supports the (case-insensitive) conditions
3353 end, all remaining conditions are non-portable extensions; note that
3354 falsely specified conditions cause the execution of the entire
3355 conditional construct until the (matching) closing
3357 command to be suppressed.
3358 The syntax of the nestable
3360 conditional execution construct requires that each condition and syntax
3361 element is surrounded by whitespace.
3363 .Bd -literal -offset indent
3372 The (case-insensitive) condition
3374 erminal will evaluate to true if the standard input is a terminal, i.e.,
3375 in interactive sessions.
3376 Another condition can be any boolean value (see the section
3377 .Sx "INTERNAL VARIABLES"
3378 for textual boolean representations) to mark an enwrapped block as
3381 .Dq always execute .
3382 It is possible to check
3383 .Sx "INTERNAL VARIABLES"
3386 variables for existence or compare their expansion against a user given
3387 value or another variable by using the
3389 .Pf ( Dq variable next )
3390 conditional trigger character;
3391 a variable on the right hand side may be signalled using the same
3393 The variable names may be enclosed in a pair of matching braces.
3396 The available comparison operators are
3400 (less than or equal to),
3406 (greater than or equal to),
3410 (is substring of) and
3412 (is not substring of).
3413 The values of the left and right hand side are treated as strings and
3414 are compared 8-bit byte-wise, ignoring case according to the rules of
3415 the US-ASCII encoding (therefore, dependend on the active locale,
3416 possibly producing false results for strings in the locale encoding).
3417 Except for the substring checks the comparison will instead be performed
3418 arithmetically if both, the user given value as well as the variable
3419 content, can be parsed as numbers (integers).
3420 An unset variable is treated as the empty string.
3423 When the \*(OPal regular expression support is available, the additional
3429 They treat the right hand side as an extended regular expression that is
3430 matched case-insensitively and according to the active
3432 locale, meaning that strings in the locale encoding should be matched
3436 Conditions can be joined via AND-OR lists (where the AND operator is
3438 and the OR operator is
3440 which have equal precedence and will be evaluated with left
3441 associativity, thus using the same syntax that is known for the
3443 It is also possible to form groups of conditions and lists by enclosing
3444 them in pairs of brackets
3445 .Ql [\ \&.\&.\&.\ ] ,
3446 which may be interlocked within each other, and also be joined via
3450 The results of individual conditions and entire groups may be modified
3451 via unary operators: the unary operator
3453 will reverse the result.
3455 .Bd -literal -offset indent
3459 if $ttycharset == "UTF-8"
3460 echo *ttycharset* is set to UTF-8, case-insensitively
3464 echo These two variables are equal
3466 if $version-major >= 15
3467 echo Running a new version..
3468 if $features =@ "regex"
3469 if $TERM =~ "^xterm\&.*"
3470 echo ..in an X terminal
3473 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
3476 if true && $debug || ${verbose}
3477 echo Left associativity, as is known from the shell
3479 if ! ! true && ! [ ! $debug && ! $verbose ]
3480 echo Unary operator support
3488 Without arguments the list of ignored header fields is shown,
3489 otherwise the given list of header fields is added to the ignore list:
3490 Header fields in the ignore list are not shown on the terminal when
3491 a message is displayed.
3492 To display a message in its entirety, use the commands
3503 Shows the names of all available commands, alphabetically sorted.
3507 This command can be used to localize changes to variables, meaning that
3508 their state will be reverted to the former one once the covered scope
3510 It can only be used inside of macro definition blocks introduced by
3514 and is interpreted as a boolean (string, see
3515 .Sx "INTERNAL VARIABLES" ) ;
3518 of an account is left once it is switched off again.
3519 .Bd -literal -offset indent
3520 define temporary_settings {
3535 enables change localization and calls
3537 which explicitly resets localization, then any value changes within
3539 will still be reverted by
3544 Reply to messages that come in via known
3547 .Pf ( Ic mlsubscribe )
3548 mailing lists, or pretend to do so (see
3549 .Sx "Mailing lists" ) :
3552 functionality this will actively resort and even remove message
3553 recipients in order to generate a message that is supposed to be sent to
3555 For example it will also implicitly generate a
3556 .Ql Mail-Followup-To:
3557 header if that seems useful, regardless of the setting of the variable
3564 but saves the message in a file named after the local part of the first
3565 recipient's address (instead of in
3570 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3571 or asks on standard input if none were given;
3572 then collects the remaining mail content and sends it out.
3576 (mb) The given message list is to be sent to
3578 when \*(UA is quit; this is the default action unless the
3581 \*(ID This command can only be used in a system mailbox (see
3586 Without any arguments the content of the MIME type cache will displayed.
3587 Otherwise each argument defines a complete MIME type specification of
3588 a type that shall be added (prepended) to the cache.
3589 In any event MIME type sources are loaded first as necessary \(en
3590 .Va mimetypes-load-control
3591 can be used to fine-tune which sources are actually loaded.
3592 Refer to the section on
3593 .Sx "The mime.types files"
3594 for more on MIME type specifications and this topic in general.
3595 MIME type unregistration and cache resets can be triggered with
3600 Without arguments the list of all currently defined mailing lists
3601 (and their attributes, if any) is shown; a more verbose listing will be
3602 produced if either of
3607 Otherwise all given arguments (which need not be quoted except for
3608 whitespace) will be added and henceforth be recognized as mailing lists.
3609 Mailing lists may be removed via the command
3612 If the \*(OPal regular expression support is available then mailing
3613 lists may also be specified as (extended) regular expressions (see
3619 Without arguments the list of all currently defined mailing lists which
3620 have a subscription attribute is shown; a more verbose listing will be
3621 produced if either of
3626 Otherwise this attribute will be set for all given mailing lists,
3627 newly creating them as necessary (as via
3629 Subscription attributes may be removed via the command
3638 but moves the messages to a file named after the local part of the
3639 sender address of the first message (instead of in
3646 but marks the messages for deletion if they were transferred
3653 but also displays ignored header fields and all MIME parts.
3661 on the given messages, even in non-interactive mode and as long as the
3662 standard output is a terminal.
3668 \*(OP When used without arguments or if
3670 has been given the content of the
3672 cache is shown, loading it first as necessary,
3675 then the cache will only be initialized and
3677 will remove its contents.
3678 Note that \*(UA will try to load the file only once, use
3679 .Ql Ic \&\&netrc Ns \:\0\:clear
3680 to unlock further attempts.
3684 .Sx "On URL syntax and credential lookup" ;
3686 .Sx "The .netrc file"
3687 documents the file format in detail.
3691 Checks for new mail in the current folder without committing any changes
3693 If new mail is present, a message is shown.
3697 the headers of each new message are also shown.
3705 Goes to the next message in sequence and types it.
3706 With an argument list, types the next matching message.
3720 If the current folder is accessed via a network connection, a
3722 command is sent, otherwise no operation is performed.
3728 but also displays ignored header fields and all MIME parts.
3736 on the given messages, even in non-interactive mode and as long as the
3737 standard output is a terminal.
3745 but also pipes ignored header fields and all parts of MIME
3746 .Ql multipart/alternative
3751 (pi) Takes a message list and a shell command
3752 and pipes the messages through the command.
3753 Without an argument the current message is piped through the command
3760 every message is followed by a formfeed character.
3781 (q) Terminates the session, saving all undeleted, unsaved messages in
3784 preserving all messages marked with
3788 or never referenced in the system mailbox,
3789 and removing all other messages from the system mailbox.
3790 If new mail has arrived during the session,
3792 .Dq You have new mail
3794 If given while editing a mailbox file with the command line flag
3796 then the edit file is rewritten.
3797 A return to the shell is effected,
3798 unless the rewrite of edit file fails,
3799 in which case the user can escape with the exit command.
3813 Removes the named folders.
3814 The user is asked for confirmation in interactive mode.
3818 Takes the name of an existing folder
3819 and the name for the new folder
3820 and renames the first to the second one.
3821 Both folders must be of the same type.
3825 (R) Reply to originator.
3826 Does not reply to other recipients of the original message.
3828 will exchange this command with
3832 is set the recipient address will be stripped from comments, names etc.
3836 (r) Take a message and group-responds to it by addressing the sender
3839 .Va followup-to-honour ,
3842 .Va recipients-in-cc
3843 influence response behaviour.
3846 offers special support for replying to mailing lists.
3849 is set recipient addresses will be stripped from comments, names etc.
3862 but initiates a group-reply regardless of the value of
3869 but responds to the sender only regardless of the value of
3876 but does not add any header lines.
3877 This is not a way to hide the sender's identity,
3878 but useful for sending a message again to the same recipients.
3882 Takes a list of messages and a user name
3883 and sends each message to the named user.
3885 and related header fields are prepended to the new copy of the message.
3903 .It Ic respondsender
3909 (ret) Without arguments the list of retained header fields is shown,
3910 otherwise the given list of header fields is added to the retain list:
3911 Header fields in the retain list are shown on the terminal when
3912 a message is displayed, all other header fields are suppressed.
3913 To display a message in its entirety, use the commands
3922 takes precedence over the mentioned.
3928 but saves the messages in a file named after the local part of the
3929 sender of the first message instead of (in
3931 and) taking a filename argument.
3935 (s) Takes a message list and a filename and appends each message in turn
3936 to the end of the file.
3937 If no filename is given, the
3940 The filename in quotes, followed by the generated character count
3941 is echoed on the user's terminal.
3942 If editing a system mailbox the messages are marked for deletion.
3943 Filename interpretation as described for the
3945 command is performed.
3962 Header fields thus marked are filtered out when saving a message by
3964 or when automatically saving to
3966 This command should only be applied to header fields that do not contain
3967 information needed to decode the message,
3968 as MIME content fields do.
3980 Header fields thus marked are the only ones saved with a message when
3983 or when automatically saving to
3988 The use of this command is strongly discouraged since it may strip
3989 header fields that are needed to decode the message correctly.
3993 Takes a message specification (list) and displays a header summary of
3994 all matching messages, as via
3996 This command is an alias of
3999 .Sx "Specifying messages" .
4003 Takes a message list and marks all messages as having been read.
4007 (se) Without arguments this command shows all variables and their
4008 values which are currently known to \*(UA.
4009 Setting any of the variables
4013 changes the output format to BSD style, otherwise a properly quoted
4014 listing is produced.
4019 has been set twice then the listing is modified to mark out assembled
4022 Otherwise modifies (set and unsets) the given variables.
4023 Arguments are of the form
4025 (no space before or after
4029 if there is no value.
4030 Quotation marks may be placed around any part of the assignment
4031 statement to quote blanks or tabs, e.g.,
4033 .Dl set indentprefix="->"
4035 If an argument begins with
4039 the effect is the same as invoking the
4041 command with the remaining part of the variable
4042 .Pf ( Ql unset save ) .
4048 except that the variables are also exported into the program environment;
4049 since this task requires native host support the command will always
4050 report error if that is not available (but still act like
4053 This operation is a no-op unless all resource files have been loaded.
4059 (sh) Invokes an interactive version of the shell.
4063 Without arguments the list of all currently defined shortcuts is
4065 Otherwise all given arguments (which need not be quoted except for
4066 whitespace) are treated as pairs of shortcuts and their expansions,
4067 creating new or changing already existing shortcuts, as necessary.
4068 Shortcuts may be removed via the command
4070 The expansion strings should be in the syntax that has been described
4079 but performs neither MIME decoding nor decryption, so that the raw
4080 message text is shown.
4084 (si) Shows the size in characters of each message of the given
4089 Shows the current sorting criterion when used without an argument.
4090 Otherwise creates a sorted representation of the current folder,
4093 command and the addressing modes such that they refer to messages in
4095 Message numbers are the same as in regular mode.
4099 a header summary in the new order is also displayed.
4100 Automatic folder sorting can be enabled by setting the
4102 variable, as in, e.g.,
4103 .Ql set autosort=thread .
4104 Possible sorting criterions are:
4106 .Bl -tag -compact -offset indent -width "subject"
4108 Sort the messages by their
4110 field, that is by the time they were sent.
4112 Sort messages by the value of their
4114 field, that is by the address of the sender.
4117 variable is set, the sender's real name (if any) is used.
4119 Sort the messages by their size.
4121 \*(OP Sort the message by their spam score, as has been classified by
4124 Sort the messages by their message status.
4126 Sort the messages by their subject.
4128 Create a threaded display.
4130 Sort messages by the value of their
4132 field, that is by the address of the recipient.
4135 variable is set, the recipient's real name (if any) is used.
4140 (so) The source command reads commands from the given file, which is
4141 subject to the usual filename expansions (see introductional words of
4143 If the given argument ends with a vertical bar
4145 then the argument will instead be interpreted as a shell command and
4146 \*(UA will read the output generated by it.
4152 (beside not supporting pipe syntax a.k.a. shell command input) is that
4153 this command will not generate an error if the given file argument
4154 cannot be opened successfully.
4155 This can matter in, e.g., resource files, since loading of those is
4156 stopped when an error is encountered.
4160 \*(OP Takes a list of messages and clears their
4166 \*(OP Takes a list of messages and causes the
4168 to forget it has ever used them to train its Bayesian filter.
4169 Unless otherwise noted the
4171 flag of the message is inspected to chose wether a message shall be
4179 \*(OP Takes a list of messages and informs the Bayesian filter of the
4183 This also clears the
4185 flag of the messages in question.
4189 \*(OP Takes a list of messages and rates them using the configured
4190 .Va spam-interface ,
4191 without modifying the messages, but setting their
4193 flag as appropriate; because the spam rating headers are lost the rate
4194 will be forgotten once the mailbox is left.
4195 Refer to the manual section
4197 for the complete picture of spam handling in \*(UA.
4201 \*(OP Takes a list of messages and sets their
4207 \*(OP Takes a list of messages and informs the Bayesian filter of the
4213 flag of the messages in question.
4222 Create a threaded representation of the current folder,
4223 i.\|e. indent messages that are replies to other messages in the header
4224 display and change the
4226 command and the addressing modes such that they refer to messages in the
4228 Message numbers are the same as in unthreaded mode.
4232 a header summary in threaded order is also displayed.
4236 (to) Takes a message list and displays the top few lines of each.
4237 The number of lines shown is controlled by the variable
4239 and defaults to five.
4243 (tou) Takes a message list and marks the messages for saving in
4245 \*(UA deviates from the POSIX standard with this command,
4248 command will display the following message instead of the current one.
4254 but also displays out ignored header fields and all parts of MIME
4255 .Ql multipart/alternative
4260 (t) Takes a message list and types out each message on the user's
4266 For MIME multipart messages, all parts with a content type of
4270 are shown, the other are hidden except for their headers.
4271 Messages are decrypted and converted to the terminal character set
4276 Delete all given accounts.
4277 An error message is shown if a given account is not defined.
4280 will discard all existing accounts.
4284 (una) Takes a list of names defined by alias commands
4285 and discards the remembered groups of users.
4288 will discard all existing aliases.
4292 Takes a message list and marks each message as not having been answered.
4296 Only applicable to threaded mode.
4297 Takes a message list and makes the message and all replies to it visible
4298 in header summaries again.
4299 When a message becomes the current message,
4300 it is automatically made visible.
4301 Also when a message with collapsed replies is displayed,
4302 all of these are automatically uncollapsed.
4308 mapping for the given colour type (see
4310 for a list of types) and mapping; if the optional precondition argument
4311 is used then only the exact tuple of mapping and precondition is removed.
4314 will remove all mappings (no precondition allowed).
4316 .Sx "Coloured display"
4317 for the general picture.
4321 Deletes the custom headers given as arguments.
4324 will remove all custom headers.
4328 Undefine all given macros.
4329 An error message is shown if a given macro is not defined.
4332 will discard all existing macros.
4336 (u) Takes a message list and marks each message as not being deleted.
4340 Takes a message list and
4346 Takes a message list and marks each message as not being
4351 Removes the header field names from the list of ignored fields for the
4356 will remove all fields.
4360 Removes the header field names from the list of retained fields for the
4365 will remove all fields.
4369 Remove all the given command
4373 will remove all ghosts.
4377 Removes the header field names from the list of ignored fields.
4380 will remove all fields.
4384 Delete all given MIME types, e.g.,
4385 .Ql unmimetype text/plain
4386 will remove all registered specifications for the MIME type
4390 will discard all existing MIME types, just as will
4392 but which also reenables cache initialization via
4393 .Va mimetypes-load-control .
4397 Forget about all the given mailing lists.
4400 will remove all lists.
4405 .It Ic unmlsubscribe
4406 Remove the subscription attribute from all given mailing lists.
4409 will clear the attribute from all lists which have it set.
4420 Takes a message list and marks each message as not having been read.
4424 Removes the header field names from the list of retained fields.
4427 will remove all fields.
4431 Removes the header field names from the list of ignored fields for
4435 will remove all fields.
4439 Removes the header field names from the list of retained fields for
4443 will remove all fields.
4447 (uns) Takes a list of option names and discards their remembered values;
4455 except that the variables are also removed from the program environment;
4456 since this task requires native host support the command will always
4457 report error if that is not available (but still act like
4460 This operation is a no-op unless all resource files have been loaded.
4466 Deletes the shortcut names given as arguments.
4469 will remove all shortcuts.
4473 Disable sorted or threaded mode
4479 return to normal message order and,
4483 displays a header summary.
4493 Decode the given URL-encoded string arguments and show the results.
4494 Note the resulting strings may not be valid in the current locale, see
4499 URL-encode the given arguments and show the results.
4500 Because the arguments effectively are in the character set of the
4501 current locale the results will vary accordingly unless the input solely
4502 consists of characters in the portable character set, see
4503 .Sx "Character sets" .
4507 Edit the values of or create the given variable(s) in the
4509 Boolean variables cannot be edited.
4513 Show informations about all the given variables.
4514 \*(UA knows about a finite set of known builtin variables that are
4515 subdivided further in boolean and value variants;
4516 they may have special properties, like
4518 (setting may not be changed) and
4520 meaning that the value is generated on-the-fly as necessary.
4521 Beside those known variables an infinite number of unknown, so-called
4523 variables, which are expected to be able to store values, may exist.
4524 .Bd -literal -offset indent
4526 ? varshow sendwait version-major foo bar
4527 "sendwait": (73) boolean: set=1 (ENVIRON=0)
4528 "version-major": (192) value, read-only, virtual:\e
4529 set=1 (ENVIRON=0) value<14>
4530 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4531 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4536 \*(OP Takes a message list and verifies each message.
4537 If a message is not a S/MIME signed message,
4538 verification will fail for it.
4539 The verification process checks if the message was signed using a valid
4541 if the message sender's email address matches one of those contained
4542 within the certificate,
4543 and if the message content has been altered.
4547 (v) Takes a message list and invokes the display editor on each message.
4548 Modified contents are discarded unless the
4554 (w) For conventional messages the body without all headers is written.
4555 The output is decrypted and converted to its native format as necessary.
4556 If the output file exists, the text is appended.
4557 If a message is in MIME multipart format its first part is written to
4558 the specified file as for conventional messages,
4559 and the user is asked for a filename to save each other part.
4560 For convience saving of each part may be skipped by giving an empty value;
4561 the same result can also be achieved by writing it to
4563 For the second and subsequent parts a leading
4565 character causes the part to be piped to the remainder of the user input
4566 interpreted as a shell command;
4567 otherwise the user input is expanded as usually for folders,
4568 e.g., tilde expansion is performed.
4569 In non-interactive mode, only the parts of the multipart message
4570 that have a filename given in the part header are written,
4571 the others are discarded.
4572 The original message is never marked for deletion in the originating
4575 the contents of the destination file are overwritten if the file
4577 No special handling of compressed files is performed.
4586 \*(UA presents message headers in windowfuls as described under the
4589 This command scrolls to the next window of messages.
4590 If an argument is given,
4591 it specifies the window to use.
4592 A number prefixed by
4596 indicates that the window is calculated in relation to the current position.
4597 A number without a prefix specifies an absolute window number,
4600 lets \*(UA scroll to the last window of messages.
4606 but scrolls to the next or previous window that contains at least one
4615 .\" .Sh TILDE ESCAPES {{{
4618 Here is a summary of the tilde escapes,
4619 which are used to perform special functions when composing messages.
4620 Tilde escapes are only recognized at the beginning of lines.
4623 is somewhat of a misnomer since the actual escape character can be
4624 changed by adjusting the option
4627 .Bl -tag -width ".Ic __ filename"
4630 Insert the string of text in the message prefaced by a single
4632 (If the escape character has been changed,
4633 that character must be doubled
4634 in order to send it at the beginning of a line.)
4637 .It Ic ~! Ar command
4638 Execute the indicated shell
4640 then return to the message.
4644 Same effect as typing the end-of-file character.
4647 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4648 Execute the given \*(UA command.
4649 Not all commands, however, are allowed.
4653 Write a summary of command escapes.
4656 .It Ic ~< Ar filename
4661 .It Ic ~<! Ar command
4663 is executed using the shell.
4664 Its standard output is inserted into the message.
4667 .It Ic ~@ Op Ar filename...
4668 With no arguments, edit the attachment list interactively.
4669 If an attachment's file name is left empty,
4670 that attachment is deleted from the list.
4671 When the end of the attachment list is reached,
4672 \*(UA will ask for further attachments until an empty name is given.
4673 If a given file name solely consists of the number sign
4675 followed by a valid message number of the currently active mailbox, then
4676 the given message is attached as a MIME
4678 and the rest of this section does not apply.
4680 If character set conversion has been compiled into \*(UA, then this mode
4681 gives the user the option to specify input and output character sets,
4682 unless the file extension indicates binary content, in which case \*(UA
4683 asks wether this step shall be skipped for the attachment in question.
4684 If not skipped, then the charset that succeeds to represent the
4685 attachment data will be used in the
4687 MIME parameter of the mail message:
4689 .Bl -bullet -compact
4691 If input and output character sets are specified, then the conversion is
4692 performed on the fly.
4693 The user will be asked repeatedly until the desired conversion succeeds.
4695 If only an output character set is specified, then the input is assumed
4698 charset and will be converted to the given output charset on the fly.
4699 The user will be asked repeatedly until the desired conversion succeeds.
4701 If no character sets are specified at all then the algorithm that is
4702 documented in the section
4703 .Sx "Character sets"
4704 is applied, but directly and on the fly.
4705 The user will be asked repeatedly until the desired conversion succeeds.
4707 Finally, if an input-, but no output character set is specified, then no
4708 conversion is ever performed, but the
4710 MIME parameter value will still be set to the user input.
4712 The character set selection loop can be left by typing
4714 i.e., causing an interrupt.
4715 .\" \*(OU next sentence
4716 Note that before \*(UA version 15.0 this terminates the entire
4717 current attachment selection, not only the character set selection.
4720 Without character set conversion support, \*(UA will ask for the input
4721 character set only, and it'll set the
4723 MIME parameter value to the given input, if any;
4724 if no user input is seen then the
4726 character set will be used for the parameter value instead.
4727 Note that the file extension check isn't performed in this mode, since
4728 no conversion will take place anyway.
4730 Note that in non-interactive mode, for reproduceabilities sake, there
4731 will always be two questions for each attachment, regardless of wether
4732 character set conversion is available and what the file extension is.
4733 The first asks for the filename, and the second asks for the input
4734 character set to be passed through to the corresponding MIME parameter;
4735 no conversion will be tried if there is input to the latter question,
4736 otherwise the usual conversion algorithm, as above, is applied.
4737 For message attachments, the answer to the second question is completely
4742 arguments are specified for the
4744 command they are treated as a comma-separated list of files,
4745 which are all expanded and appended to the end of the attachment list.
4746 (Commas need to be escaped with backslash, but filenames with leading or
4747 trailing whitespace can only be added via the command line or the first
4749 Message attachments can only be added via the first method;
4750 filenames which clash with message numbers can only be added via the
4751 command line or the second method.)
4752 In this mode the (text) attachments are assumed to be in
4754 encoding, and will be evaluated as documented in the section
4755 .Sx "Character sets" .
4759 Inserts the string contained in the
4762 .Ql Ic ~i Ns \0Sign ) .
4763 The escape sequences tabulator
4771 Inserts the string contained in the
4774 .Ql Ic ~i Ns \0sign ) .
4775 The escape sequences tabulator
4782 .It Ic ~b Ar name ...
4783 Add the given names to the list of blind carbon copy recipients.
4786 .It Ic ~c Ar name ...
4787 Add the given names to the list of carbon copy recipients.
4791 Read the file specified by the
4793 variable into the message.
4797 Invoke the text editor on the message collected so far.
4798 After the editing session is finished,
4799 the user may continue appending text to the message.
4802 .It Ic ~F Ar messages
4803 Read the named messages into the message being sent, including all
4804 message headers and MIME parts.
4805 If no messages are specified, read in the current message.
4808 .It Ic ~f Ar messages
4809 Read the named messages into the message being sent.
4810 If no messages are specified, read in the current message.
4814 lists are used to modify the message headers.
4815 For MIME multipart messages,
4816 only the first displayable part is included.
4820 Edit the message header fields
4825 by typing each one in turn and allowing the user to edit the field.
4826 The default values for these fields originate from the
4834 Edit the message header fields
4840 by typing each one in turn and allowing the user to edit the field.
4843 .It Ic ~i Ar variable
4844 Insert the value of the specified variable into the message,
4845 adding a newline character at the end.
4846 The message remains unaltered if the variable is unset or empty.
4847 The escape sequences tabulator
4854 .It Ic ~M Ar messages
4855 Read the named messages into the message being sent,
4858 If no messages are specified, read the current message.
4861 .It Ic ~m Ar messages
4862 Read the named messages into the message being sent,
4865 If no messages are specified, read the current message.
4869 lists are used to modify the message headers.
4870 For MIME multipart messages,
4871 only the first displayable part is included.
4875 Display the message collected so far,
4876 prefaced by the message header fields
4877 and followed by the attachment list, if any.
4881 Abort the message being sent,
4882 copying it to the file specified by the
4889 .It Ic ~R Ar filename
4890 Read the named file into the message, indented by
4894 .It Ic ~r Ar filename
4895 Read the named file into the message.
4899 Cause the named string to become the current subject field.
4902 .It Ic ~t Ar name ...
4903 Add the given name(s) to the direct recipient list.
4906 .It Ic ~U Ar messages
4907 Read in the given / current message(s) excluding all headers, indented by
4911 .It Ic ~u Ar messages
4912 Read in the given / current message(s), excluding all headers.
4916 Invoke an alternate editor (defined by the
4918 option) on the message collected so far.
4919 Usually, the alternate editor will be a screen editor.
4920 After the editor is quit,
4921 the user may resume appending text to the end of the message.
4924 .It Ic ~w Ar filename
4925 Write the message onto the named file.
4927 the message is appended to it.
4933 except that the message is not saved at all.
4936 .It Ic ~| Ar command
4937 Pipe the message through the specified filter command.
4938 If the command gives no output or terminates abnormally,
4939 retain the original text of the message.
4942 is often used as a rejustifying filter.
4947 .\" .Sh INTERNAL VARIABLES {{{
4948 .Sh "INTERNAL VARIABLES"
4950 Internal \*(UA variables are controlled via the
4954 commands; prefixing a variable name with the string
4958 has the same effect as using
4964 Creation or editing of variables can be performed in the
4969 will give more insight on the given variable(s), and
4971 when called without arguments, will show a listing of all variables.
4972 Variables are also implicitly inherited from the program
4974 and can be set explicitly via the command line option
4978 Two different kind of variables exist.
4979 There are boolean variables, which can only be in one of the two states
4983 and value variables with a(n optional) string value.
4984 For the latter proper quoting is necessary upon assignment time:
4985 To embed whitespace (space and tabulator) in a value it either needs to
4986 be escaped with a backslash character, or the entire value must be
4987 enclosed in (double or single) quotation marks;
4988 To use quotation marks identical to those used to enclose the value,
4989 escape them with a backslash character.
4990 The backslash character has no special meaning except in these cases.
4992 .Bd -literal -offset indent
4993 set one=val\e 1 two="val 2" \e
4994 three='val "3"' four='val \e'4\e''
4995 varshow one two three four
4996 unset one two three four
5000 Dependent upon the actual option the string values will be interpreted
5001 as numbers, colour names, normal text etc., but there also exists
5002 a special kind of string value, the
5003 .Dq boolean string ,
5004 which must either be a decimal integer (in which case
5008 and any other value is true) or any of the (case-insensitive) strings
5013 for a false boolean and
5018 for a true boolean; a special kind of boolean string is the
5020 which is a boolean string that can optionally be prefixed with the
5021 (case-insensitive) term
5025 which causes prompting of the user in interactive mode, with the given
5026 boolean as the default value.
5028 .\" .Ss "Initial settings" {{{
5029 .\" (Keep in SYNC: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
5030 .Ss "Initial Settings"
5032 The standard POSIX 2008/Cor 1-2013 mandates the following initial
5038 .Pf no Va autoprint ,
5052 .Pf no Va ignoreeof ,
5054 .Pf no Va keepsave ,
5056 .Pf no Va outfolder ,
5061 (note that \*(UA deviates from the standard by using
5065 special prompt escape results in
5073 .Pf no Va sendwait ,
5082 Notes: \*(UA doesn't support the
5084 variable \(en use command line options or
5085 .Va sendmail-arguments
5086 to pass options through to a MTA.
5087 And the default global
5089 file (which is loaded unless the
5091 command line flag has been used or the
5092 .Ev NAIL_NO_SYSTEM_RC
5093 environment variable is set) bends those initial settings a bit, e.g.,
5094 it sets the variables
5099 to name a few, calls
5101 etc., and should thus be taken into account.
5104 .\" .Ss "Variables" {{{
5107 .Bl -tag -width ".It Va _utoprin_"
5109 .It Va add-file-recipients
5110 \*(BO When file or pipe recipients have been specified,
5111 mention them in the corresponding address fields of the message instead
5112 of silently stripping them from their recipient list.
5113 By default such addressees are not mentioned.
5115 .Mx Va agent-shell-lookup
5116 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5118 \*(IN\*(OP Account passwords can be fetched via an external agent
5119 program in order to permit encrypted password storage \(en see
5120 .Sx "On URL syntax and credential lookup"
5121 for more on credential lookup.
5122 If this is set then the content is interpreted as a shell command the
5123 output of which (with newline characters removed) is treated as the
5124 account password shall the command succeed (and have produced non-empty
5125 non-newline output); e.g., via
5127 .Bd -literal -offset indent
5128 $ echo PASSWORD > .pass
5130 $ eval `gpg-agent --daemon \e
5131 --pinentry-program=/usr/bin/pinentry-curses \e
5132 --max-cache-ttl 99999 --default-cache-ttl 99999`
5133 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5137 A couple of environment variables will be set for the agent:
5139 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5141 The temporary directory that \*(UA uses.
5142 Usually identical to
5144 but guaranteed to be set and usable by child processes;
5145 to ensure the latter condition for
5151 for which the password is looked up.
5152 .It Ev NAIL_USER_ENC
5153 The URL percent-encoded variant of
5156 The plain machine hostname of the user account.
5157 .It Ev NAIL_HOST_PORT
5160 (hostname possibly including port) of the user account.
5165 \*(BO Causes only the local part to be evaluated
5166 when comparing addresses.
5170 \*(BO Causes messages saved in
5172 to be appended to the end rather than prepended.
5173 This should always be set.
5177 \*(BO Causes \*(UA to prompt for the subject of each message sent.
5178 If the user responds with simply a newline,
5179 no subject field will be sent.
5183 \*(BO Causes the prompts for
5187 lists to appear after the message has been edited.
5191 \*(BO If set, \*(UA asks for files to attach at the end of each message,
5192 shall the list be found empty at that time.
5193 An empty line finalizes the list.
5197 \*(BO Causes the user to be prompted for carbon copy recipients
5198 (at the end of each message if
5202 are set) shall the list be found empty (at that time).
5203 An empty line finalizes the list.
5207 \*(BO Causes the user to be prompted for blind carbon copy
5208 recipients (at the end of each message if
5212 are set) shall the list be found empty (at that time).
5213 An empty line finalizes the list.
5217 \*(BO\*(OP Causes the user to be prompted if the message is to be
5218 signed at the end of each message.
5221 variable is ignored when this variable is set.
5225 \*(BO Alternative name for
5232 .It Va attachment-ask-content-description , \
5233 attachment-ask-content-disposition , \
5234 attachment-ask-content-id , \
5235 attachment-ask-content-type
5236 \*(BO If set then the user will be prompted for some attachment
5237 information when editing the attachment list.
5238 It is advisable to not use these but for the first of the variables;
5239 even for that it has to be noted that the data is used
5245 A sequence of characters to display in the
5249 as shown in the display of
5251 each for one type of messages (see
5252 .Sx "Message states" ) ,
5253 with the default being
5256 .Ql NU\ \ *HMFAT+\-$~
5259 variable is set, in the following order:
5261 .Bl -tag -compact -offset indent -width ".It Ql _"
5283 start of a collapsed thread.
5285 an uncollapsed thread (TODO ignored for now).
5289 classified as possible spam.
5295 Specifies a list of recipients to which a blind carbon copy of each
5296 outgoing message will be sent automatically.
5300 Specifies a list of recipients to which a carbon copy of each outgoing
5301 message will be sent automatically.
5305 \*(BO Causes threads to be collapsed automatically when threaded mode
5312 \*(BO Causes the delete command to behave like
5314 thus, after deleting a message the next one will be typed automatically.
5318 \*(BO\*(OB Causes threaded mode (see the
5320 command) to be entered automatically when a folder is opened.
5322 .Ql autosort=thread .
5326 Causes sorted mode (see the
5328 command) to be entered automatically with the value of this option as
5329 sorting method when a folder is opened, e.g.,
5330 .Ql set autosort=thread .
5334 \*(BO Enables the substitution of
5336 by the contents of the last command line in shell escapes.
5339 .It Va batch-exit-on-error
5340 \*(BO If the batch mode has been enabled via the
5342 command line option, then this variable will be consulted whenever \*(UA
5343 completes one operation (returns to the command prompt); if it is set
5344 then \*(UA will terminate if the last operation generated an error.
5348 \*(BO Causes automatic display of a header summary after executing a
5354 \*(BO Sets some cosmetical features to traditional BSD style;
5355 has the same affect as setting
5357 and all other variables prefixed with
5359 it also changes the meaning of the \*(UA specific
5362 escape sequence and changes behaviour of
5364 (which doesn't exist in BSD).
5368 \*(BO Changes the letters shown in the first column of a header
5369 summary to traditional BSD style.
5373 \*(BO Changes the display of columns in a header summary to traditional
5378 \*(BO Changes some informational messages to traditional BSD style.
5384 field to appear immediately after the
5386 field in message headers and with the
5388 .Sx "TILDE ESCAPES" .
5392 \*(BO Changes the output format of the
5394 command to traditional BSD style.
5398 The value that should appear in the
5402 MIME header fields when no character set conversion of the message data
5404 This defaults to US-ASCII, and the chosen character set should be
5405 US-ASCII compatible.
5409 \*(OP The default 8-bit character set that is used as an implicit last
5410 member of the variable
5412 This defaults to UTF-8.
5413 If no character set conversion capabilities are available in \*(UA then
5414 the only supported character set is
5416 Refer to the section
5417 .Sx "Character sets"
5418 for the complete picture of character set conversion in \*(UA.
5421 .It Va charset-unknown-8bit
5422 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5424 the content of a mail message by using a character set with the name
5426 Because of the unclassified nature of this character set \*(UA will not
5427 be capable to convert this character set to any other character set.
5428 If this variable is set any message part which uses the character set
5430 is assumed to really be in the character set given in the value,
5431 otherwise the (final) value of
5433 is used for this purpose.
5435 This variable will also be taken into account if a MIME type (see
5436 .Sx "The mime.types files" )
5437 of a MIME message part that uses the
5439 character set is forcefully treated as text.
5443 The default value for the
5448 .It Va colour-disable
5449 \*(BO\*(OP Forcefully disable usage of colours.
5450 Also see the section
5451 .Sx "Coloured display" .
5455 \*(BO\*(OP Wether colour shall be used for output that is paged through
5457 Note that pagers may need special flags, e.g.,
5465 in order to support colours.
5466 Often doing manual adjustments is unnecessary since \*(UA may perform
5467 adjustments dependend on the value of the environment variable
5469 (see there for more).
5473 In a(n interactive) terminal session, then if this valued option is set
5474 it'll be used as a threshold to determine how many lines the given
5475 output has to span before it will be displayed via the configured
5479 can be forced by setting this to the value
5481 setting it without a value will deduce the current height of the
5482 terminal screen to compute the treshold (see
5490 \*(OB A variable counterpart of the
5492 command (see there for documentation), interpreted as a comma-separated
5493 list of custom headers to be injected, to include commas in the header
5494 bodies escape them with backslash, e.g.:
5496 .Dl set customhdr="Hdr1: Body1-1\e, Body1-2, Hdr2: Body2"
5502 the message date, if any is to be displayed according to the format of
5504 is by default taken from the
5506 line of the message.
5507 If this variable is set the date as given in the
5509 header field is used instead, converted to local time.
5510 To control the display format of the date assign a valid
5515 format should not be used, because \*(UA doesn't take embedded newlines
5516 into account when calculating how many lines fit onto the screen.)
5518 .Va datefield-markout-older .
5521 .It Va datefield-markout-older
5522 This option, when set in addition to
5526 messages (concept is rather comparable to the
5528 option of the POSIX utility
5530 The content interpretation is identical to
5535 \*(BO Enables debug messages and obsoletion warnings, disables the
5536 actual delivery of messages and also implies
5542 .It Va disposition-notification-send
5544 .Ql Disposition-Notification-To:
5545 header (RFC 3798) with the message.
5549 .\" TODO .It Va disposition-notification-send-HOST
5551 .\".Va disposition-notification-send
5552 .\" for SMTP accounts on a specific host.
5553 .\" TODO .It Va disposition-notification-send-USER@HOST
5555 .\".Va disposition-notification-send
5556 .\"for a specific account.
5560 \*(BO When dot is set, a period
5562 on a line by itself during message input in (interactive) compose mode
5563 will be treated as end-of-message (in addition to the normal end-of-file
5572 .It Va dotlock-ignore-error
5573 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5574 mailboxes (see the command
5576 will be protected with so-called dotlock files\(emthe traditional mail
5577 spool file locking method\(emin addition to system file locking.
5578 Because \*(UA ships with a privilege-separated dotlock creation program
5579 that should always be able to create such a dotlock file there is no
5580 good reason to ignore dotlock file creation errors, and thus these are
5581 fatal unless this variable is set.
5585 \*(BO If this variable is set then the editor is started automatically
5586 when a message is composed in interactive mode, as if the
5592 variable is implied for this automatically spawned editor session.
5596 \*(BO When a message is edited while being composed,
5597 its header is included in the editable text.
5607 fields are accepted within the header, other fields are ignored.
5611 \*(BO When entering interactive mode \*(UA normally writes
5612 .Dq \&No mail for user
5613 and exits immediately if a mailbox is empty or doesn't exist.
5614 If this option is set \*(UA starts even with an empty or nonexistent
5615 mailbox (the latter behaviour furtherly depends upon
5621 Suggestion for the MIME encoding to use in outgoing text messages
5623 Valid values are the default
5624 .Ql quoted-printable ,
5629 may cause problems when transferring mail messages over channels that
5630 are not ESMTP (RFC 1869) compliant.
5631 If there is no need to encode a message,
5633 transfer mode is always used regardless of this variable.
5634 Binary data is always encoded as
5639 If defined, the first character of this option
5640 gives the character to use in place of
5643 .Sx "TILDE ESCAPES" .
5647 If not set then file and command pipeline targets are not allowed,
5648 and any such address will be filtered out, giving a warning message.
5649 If set without a value then all possible recipient address
5650 specifications will be accepted \(en see the section
5651 .Sx "On sending mail, and non-interactive mode"
5653 To accept them, but only in interactive mode, or when tilde commands
5654 were enabled explicitly by using one of the command line options
5658 set this to the (case-insensitive) value
5660 (note right now this is actually like setting
5661 .Ql restrict,-all,+name,+addr ) .
5663 In fact the value is interpreted as a comma-separated list of values.
5666 then the existence of disallowed specifications is treated as a hard
5667 send error instead of only filtering them out.
5668 The remaining values specify wether a specific type of recipient
5669 address specification is allowed (optionally indicated by a plus sign
5671 prefix) or disallowed (prefixed with a hyphen
5675 addresses all possible address specifications,
5679 command pipeline targets,
5681 plain user names and (MTA) aliases (\*(OB
5683 may be used as an alternative syntax to
5688 These kind of values are interpreted in the given order, so that
5689 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5690 will cause hard errors for any non-network address recipient address
5691 unless \*(UA is in interactive mode or has been started with the
5695 command line option; in the latter case(s) any address may be used, then.
5699 Unless this variable is set additional mail-transfer-agent (MTA)
5700 arguments from the command line, as can be given after a
5702 separator, are ignored due to safety reasons.
5703 However, if set to the special (case-insensitive) value
5705 then the presence of additional MTA arguments is treated as a hard
5706 error that causes \*(UA to exit with failure status.
5707 A lesser strict variant is the otherwise identical
5709 which does accept such arguments in interactive mode, or if tilde
5710 commands were enabled explicitly by using one of the command line options
5717 \*(RO Information on the features compiled into \*(UA \(en the content
5718 of this variable is identical to the output of the command
5723 \*(BO This option reverses the meanings of a set of reply commands,
5724 turning the lowercase variants, which by default address all recipients
5725 included in the header of a message
5726 .Pf ( Ic reply , respond , followup )
5727 into the uppercase variants, which by default address the sender only
5728 .Pf ( Ic Reply , Respond , Followup )
5731 .Ic replysender , respondsender , followupsender
5733 .Ic replyall , respondall , followupall
5734 are not affected by the current setting of
5739 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5740 It is possible to install file hooks which will be used by the
5742 command in order to be able to transparently handle (through an
5743 intermediate temporary file) files with specific
5745 s: the variable values can include shell snippets and are expected to
5746 write data to standard output / read data from standard input,
5748 \*(ID The variables may not be changed while there is a mailbox
5750 .Bd -literal -offset indent
5751 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5752 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5753 record=+null-sent.xy
5758 The name of the directory to use for storing folders of messages.
5759 All folder names that begin with
5761 refer to files below it.
5762 The same special conventions as documented for the
5764 command may be used when specifying a new value for
5766 but be aware that the expansion is fully performed immediately.
5770 This variable can be set to the name of a
5772 macro which will be called whenever a
5775 The macro will also be invoked when new mail arrives,
5776 but message lists for commands executed from the macro
5777 only include newly arrived messages then.
5779 are activated by default in a folder hook, causing the covered settings
5780 to be reverted once the folder is left again.
5783 Macro behaviour, including option localization, will change in v15.
5784 Please be aware of that and possibly embed a version check in a resource
5788 .It Va folder-hook-FOLDER
5793 Unlike other folder specifications, the fully expanded name of a folder,
5794 without metacharacters, is used to avoid ambiguities.
5795 However, if the mailbox resides under
5799 specification is tried in addition, e.g., if
5803 (and thus relative to the user's home directory) then
5804 .Pa /home/usr1/mail/sent
5806 .Ql folder-hook-/home/usr1/mail/sent
5807 first, but then followed by
5808 .Ql folder-hook-+sent .
5812 \*(BO Controls wether a
5813 .Ql Mail-Followup-To:
5814 header is generated when sending messages to known mailing lists.
5816 .Va followup-to-honour
5818 .Ic mlist , mlsubscribe , reply
5823 .It Va followup-to-honour
5825 .Ql Mail-Followup-To:
5826 header is honoured when group-replying to a message via
5830 This is a quadoption; if set without a value it defaults to
5840 .It Va forward-as-attachment
5841 \*(BO Original messages are normally sent as inline text with the
5844 and only the first part of a multipart message is included.
5845 With this option messages are sent as unmodified MIME
5847 attachments with all of their parts included.
5851 The address (or a list of addresses) to put into the
5853 field of the message header, quoting RFC 5322:
5854 the author(s) of the message, that is, the mailbox(es) of the person(s)
5855 or system(s) responsible for the writing of the message.
5856 If replying to messages these addresses are handled as if they were in
5860 If the machine's hostname is not valid at the Internet (for example at
5861 a dialup machine) then either this variable or
5866 adds even more fine-tuning capabilities),
5870 contains more than one address,
5873 variable is required (according to the standard RFC 5322).
5877 \*(BO When replying to or forwarding a message \*(UA normally removes
5878 the comment and name parts of email addresses.
5879 If this variable is set such stripping is not performed,
5880 and comments, names etc. are retained.
5884 The string to put before the text of a message with the
5888 .Va forward-as-attachment
5891 .Dq -------- Original Message --------
5892 if unset; No heading is put if it is set to the empty string.
5896 \*(BO Causes the header summary to be written at startup and after
5897 commands that affect the number of messages or the order of messages in
5898 the current folder; enabled by default.
5899 The command line option
5907 A format string to use for the summary of
5909 similar to the ones used for
5912 Format specifiers in the given string start with a percent character
5914 and may be followed by an optional decimal number indicating the field
5915 width \(em if that is negative, the field is to be left-aligned.
5916 Valid format specifiers are:
5919 .Bl -tag -compact -offset indent -width "_%%_"
5921 A plain percent character.
5924 a space character but for the current message
5926 for which it expands to
5930 a space character but for the current message
5932 for which it expands to
5935 \*(OP The spam score of the message, as has been classified via the
5938 Shows only a replacement character if there is no spam support.
5940 Message attribute character (status flag); the actual content can be
5944 The date when the message was received, or the date found in the
5948 variable is set (optionally to a date display format string).
5950 The indenting level in threaded mode.
5952 The address of the message sender.
5954 The message thread tree structure.
5955 (Note that this format doesn't support a field width.)
5957 The number of lines of the message, if available.
5961 The number of octets (bytes) in the message, if available.
5963 Message subject (if any).
5965 Message subject (if any) in double quotes.
5967 Message recipient flags: is the addressee of the message a known or
5968 subscribed mailing list \(en see
5973 The position in threaded/sorted order.
5977 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
5979 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
5990 .It Va headline-bidi
5991 Bidirectional text requires special treatment when displaying headers,
5992 because numbers (in dates or for file sizes etc.) will not affect the
5993 current text direction, in effect resulting in ugly line layouts when
5994 arabic or other right-to-left text is to be displayed.
5995 On the other hand only a minority of terminals is capable to correctly
5996 handle direction changes, so that user interaction is necessary for
5998 Note that extended host system support is required nonetheless, e.g.,
5999 detection of the terminal character set is one precondition;
6000 and this feature only works in an Unicode (i.e., UTF-8) locale.
6002 In general setting this variable will cause \*(UA to encapsulate text
6003 fields that may occur when displaying
6005 (and some other fields, like dynamic expansions in
6007 with special Unicode control sequences;
6008 it is possible to fine-tune the terminal support level by assigning
6010 no value (or any value other than
6015 will make \*(UA assume that the terminal is capable to properly deal
6016 with Unicode version 6.3, in which case text is embedded in a pair of
6017 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6019 In addition no space on the line is reserved for these characters.
6021 Weaker support is chosen by using the value
6023 (Unicode 6.3, but reserve the room of two spaces for writing the control
6024 sequences onto the line).
6029 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6030 again reserves room for two spaces in addition.
6034 \*(OP If a line editor is available then this can be set to
6035 name the (expandable) path of the location of a permanent history file.
6038 .It Va history-gabby
6039 \*(BO\*(OP Add more entries to the history as is normally done.
6042 .It Va history-gabby-persist
6043 \*(BO\*(OP \*(UA's own MLE will not save the additional
6045 entries in persistent storage unless this variable is set.
6046 On the other hand it will not loose the knowledge of wether a persistent
6047 entry was gabby or not.
6053 \*(OP If a line editor is available this value restricts the
6054 amount of history entries that are saved into a set and valid
6056 A value of less than 0 disables this feature;
6057 note that loading and incorporation of
6059 upon program startup can also be suppressed by doing this.
6060 An unset or invalid value, or 0, causes a default value to be used.
6061 Dependent on the available line editor this will also define the
6062 number of history entries in memory;
6063 it is also editor-specific wether runtime updates of this value will be
6068 \*(BO This option is used to hold messages in the system mailbox,
6069 and it is set by default.
6073 Use this string as hostname when expanding local addresses instead of
6074 the value obtained from
6085 transport is not used then it is normally the responsibility of the MTA
6086 to create these fields, \*(IN in conjunction with
6090 also influences the results;
6091 you should produce some test messages with the desired combination of
6100 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
6101 names according to the rules of IDNA (internationalized domain names
6103 Since the IDNA code assumes that domain names are specified with the
6105 character set, an UTF-8 locale charset is required to represent all
6106 possible international domain names (before conversion, that is).
6110 \*(BO Ignore interrupt signals from the terminal while entering
6111 messages; instead echo them as
6113 characters and discard the current line.
6117 \*(BO Ignore end-of-file conditions
6118 .Pf ( Ql control-D )
6119 in compose mode on message input and in interactive command input.
6120 If set an interactive command input session can only be left by
6121 explicitly using one of the commands
6125 and message input in compose mode can only be terminated by entering
6128 on a line by itself or by using the
6130 .Sx "TILDE ESCAPES" ;
6132 overrides a setting of
6144 option for indenting messages,
6145 in place of the normal tabulator character
6147 which is the default.
6148 Be sure to quote the value if it contains spaces or tabs.
6152 \*(BO If set, an empty mailbox file is not removed.
6153 This may improve the interoperability with other mail user agents
6154 when using a common folder directory, and prevents malicious users
6155 from creating fake mailboxes in a world-writable spool directory.
6156 Note this only applies to local regular (MBOX) files, other mailbox
6157 types will never be removed.
6160 .It Va keep-content-length
6161 \*(BO When (editing messages and) writing
6163 mailbox files \*(UA can be told to keep the
6167 header fields that some MUAs generate by setting this variable.
6168 Since \*(UA does neither use nor update these non-standardized header
6169 fields (which in itself shows one of their conceptual problems),
6170 stripping them should increase interoperability in between MUAs that
6171 work with with same mailbox files.
6172 Note that, if this is not set but
6173 .Va writebackedited ,
6174 as below, is, a possibly performed automatic stripping of these header
6175 fields already marks the message as being modified.
6179 \*(BO When a message is saved it is usually discarded from the
6180 originating folder when \*(UA is quit.
6181 Setting this option causes all saved message to be retained.
6184 .It Va line-editor-disable
6185 \*(BO Turn off any enhanced line editing capabilities (see
6186 .Sx "On terminal control and line editor"
6191 \*(BO When a message is replied to and this variable is set,
6192 it is marked as having been answered.
6193 This mark has no technical meaning in the mail system;
6194 it just causes messages to be marked in the header summary,
6195 and makes them specially addressable.
6199 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6201 Messages which are fetched over the network or from within already
6202 existing Maildir (or any non-MBOX) mailboxes may require so-called
6204 quoting (insertion of additional
6206 characters to prevent line content misinterpretation) to be applied in
6207 order to be storable in MBOX mailboxes, however, dependent on the
6208 circumspection of the message producer.
6209 (E.g., \*(UA itself will, when newly generating messages, choose a
6210 .Pf Content-Transfer- Va encoding
6211 that prevents the necessity for such quoting \(en a necessary
6212 precondition to ensure message checksums won't change.)
6214 By default \*(UA will perform this
6216 quoting in a way that results in a MBOX file that is compatible with
6217 the POSIX MBOX layout, which means that, in order not to exceed the
6218 capabilities of simple applications, many more
6220 lines get quoted (thus modified) than necessary according to RFC 4155.
6221 Set this option to instead generate MBOX files which comply to RFC 4155.
6225 \*(BO Internal development variable.
6228 .It Va message-id-disable
6229 \*(BO By setting this option the generation of
6231 can be completely suppressed, effectively leaving this task up to the
6232 mail-transfer-agent (MTA) or the SMTP server.
6233 (According to RFC 5321 your SMTP server is not required to add this
6234 field by itself, so you should ensure that it accepts messages without a
6238 .It Va message-inject-head
6239 A string to put at the beginning of each new message.
6240 The escape sequences tabulator
6247 .It Va message-inject-tail
6248 A string to put at the end of each new message.
6249 The escape sequences tabulator
6257 \*(BO Usually, when an
6259 expansion contains the sender, the sender is removed from the expansion.
6260 Setting this option suppresses these removals.
6265 option to be passed to mail-transfer-agents (MTAs);
6266 though most of the modern MTAs don't (no longer) document this flag, no
6267 MTA is known which doesn't support it (for historical compatibility).
6270 .It Va mime-allow-text-controls
6271 \*(BO When sending messages, each part of the message is MIME-inspected
6272 in order to classify the
6275 .Ql Content-Transfer-Encoding:
6278 that is required to send this part over mail transport, i.e.,
6279 a computation rather similar to what the
6281 command produces when used with the
6285 This classification however treats text files which are encoded in
6286 UTF-16 (seen for HTML files) and similar character sets as binary
6287 octet-streams, forcefully changing any
6292 .Ql application/octet-stream :
6293 If that actually happens a yet unset charset MIME parameter is set to
6295 effectively making it impossible for the receiving MUA to automatically
6296 interpret the contents of the part.
6298 If this option is set, and the data was unambiguously identified as text
6299 data at first glance (by a
6303 file extension), then the original
6305 will not be overwritten.
6308 .It Va mime-alternative-favour-rich
6309 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6310 HTML) will be preferred in favour of included plain text versions when
6311 displaying messages, provided that a handler exists which produces
6312 output that can be (re)integrated into \*(UA's normal visual display.
6313 (E.g., at the time of this writing some newsletters ship their full
6314 content only in the rich HTML part, whereas the plain text part only
6315 contains topic subjects.)
6318 .It Va mime-counter-evidence
6321 field is used to decide how to handle MIME parts.
6322 Some MUAs however don't use
6324 or a similar mechanism to correctly classify content, but simply specify
6325 .Ql application/octet-stream ,
6326 even for plain text attachments like
6328 If this variable is set then \*(UA will try to classify such MIME
6329 message parts on its own, if possible, for example via a possibly
6330 existent attachment filename.
6331 A non-empty value may also be given, in which case a number is expected,
6332 actually a carrier of bits.
6333 Creating the bit-carrying number is a simple addition:
6334 .Bd -literal -offset indent
6335 ? !echo Value should be set to $((2 + 4 + 8))
6336 Value should be set to 14
6339 .Bl -bullet -compact
6341 If bit two is set (2) then the detected
6343 content-type will be carried along with the message and be used for
6345 .Va pipe-TYPE/SUBTYPE
6346 is responsible for the MIME part, shall that question arise;
6347 when displaying such a MIME part the part-info will indicate the
6348 overridden content-type by showing a plus-sign
6351 If bit three is set (4) then the counter-evidence is always produced
6352 and a positive result will be used as the MIME type, even forcefully
6353 overriding the parts given MIME type.
6355 If bit four is set (8) then as a last resort the actual content of
6356 .Ql application/octet-stream
6357 parts will be inspected, so that data which looks like plain text can be
6362 .It Va mimetypes-load-control
6363 This option can be used to control which of the
6365 databases are loaded by \*(UA, as furtherly described in the section
6366 .Sx "The mime.types files" .
6369 is part of the option value, then the user's personal
6371 file will be loaded (if it exists); likewise the letter
6373 controls loading of the system wide
6374 .Pa /etc/mime.types ;
6375 directives found in the user file take precedence, letter matching is
6377 If this option is not set \*(UA will try to load both files.
6378 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6379 but they will be matched last.
6381 More sources can be specified by using a different syntax: if the
6382 value string contains an equals sign
6384 then it is instead parsed as a comma-separated list of the described
6387 pairs; the given filenames will be expanded and loaded, and their
6388 content may use the extended syntax that is described in the section
6389 .Sx "The mime.types files" .
6390 Directives found in such files always take precedence (are prepended to
6391 the MIME type cache).
6394 .It Va NAIL_EXTRA_RC
6395 The name of an optional startup file to be read last.
6396 This variable has an effect only if it is set in any of the
6397 .Sx "Resource files" ,
6398 it is not imported from the environment.
6399 Use this file for commands that are not understood by other POSIX
6404 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6405 \*(BO\*(IN\*(OP Used to control usage of the users
6407 file for lookup of account credentials, as documented in the section
6408 .Sx "On URL syntax and credential lookup"
6412 .Sx "The .netrc file"
6413 documents the file format.
6417 If this variable has the value
6419 newly created local folders will be in Maildir format.
6423 Checks for new mail in the current folder each time the prompt is shown.
6424 A Maildir folder must be re-scanned to determine if new mail has arrived.
6425 If this variable is set to the special value
6427 then a Maildir folder will not be rescanned completely, but only
6428 timestamp changes are detected.
6432 .It Va on-compose-enter , on-compose-leave
6433 \*(ID Macro hooks which will be executed before compose mode is
6434 entered, and after composing has been finished, respectively.
6435 Please note that this interface is very likely to change in v15, and
6436 should therefore possibly even be seen as experimental.
6438 are by default enabled for these hooks, causing any setting to be
6439 forgotten after the message has been sent.
6440 The following variables will be set temporarily during execution of the
6443 .Bl -tag -compact -width ".It Va compose_subject"
6446 .It Va compose-sender
6448 .It Va compose-to , compose-cc , compose-bcc
6449 The list of receiver addresses as a space-separated list.
6450 .It Va compose-subject
6456 \*(BO Causes the filename given in the
6459 and the sender-based filenames for the
6463 commands to be interpreted relative to the directory given in the
6465 variable rather than to the current directory,
6466 unless it is set to an absolute pathname.
6470 \*(BO If set, each message feed through the command given for
6472 is followed by a formfeed character
6476 .It Va password-USER@HOST , password-HOST , password
6477 \*(IN Variable chain that sets a password, which is used in case none has
6478 been given in the protocol and account-specific URL;
6479 as a last resort \*(UA will ask for a password on the user's terminal if
6480 the authentication method requires a password.
6481 Specifying passwords in a startup file is generally a security risk;
6482 the file should be readable by the invoking user only.
6484 .It Va password-USER@HOST
6485 \*(OU (see the chain above for \*(IN)
6486 Set the password for
6490 If no such variable is defined for a host,
6491 the user will be asked for a password on standard input.
6492 Specifying passwords in a startup file is generally a security risk;
6493 the file should be readable by the invoking user only.
6497 \*(BO Send messages to the
6499 command without performing MIME and character set conversions.
6503 .It Va pipe-TYPE/SUBTYPE
6504 When a MIME message part of type
6506 (case-insensitive) is displayed or quoted,
6507 its text is filtered through the value of this variable interpreted as
6511 forces interpretation of the message part as plain text, e.g.,
6512 .Ql set pipe-application/xml=@
6513 will henceforth display XML
6515 (The same could also be achieved by adding a MIME type marker with the
6518 And \*(OPally MIME type handlers may be defined via
6519 .Sx "The Mailcap files"
6520 \(em corresponding flag strings are shown in parenthesis below.)
6525 can in fact be used to adjust usage and behaviour of a following shell
6526 command specification by appending trigger characters to it, e.g., the
6527 following hypothetical command specification could be used:
6528 .Bd -literal -offset indent
6529 set pipe-X/Y="@*!++=@vim ${NAIL_FILENAME_TEMPORARY}"
6533 .Bl -tag -compact -width ".It Ql __"
6535 Simply by using the special
6537 prefix the MIME type (shell command) handler will only be invoked to
6538 display or convert the MIME part if the message is addressed directly
6539 and alone by itself.
6540 Use this trigger to disable this and always invoke the handler
6541 .Pf ( Cd x-mailx-always ) .
6544 If set the handler will not be invoked when a message is to be quoted,
6545 but only when it will be displayed
6546 .Pf ( Cd x-mailx-noquote ) .
6549 The command will be run asynchronously, i.e., without blocking \*(UA,
6550 which may be a handy way to display a, e.g., PDF file while also
6551 continuing to read the mail message
6552 .Pf ( Cd x-mailx-async ) .
6553 Asynchronous execution implies
6557 The command must be run on an interactive terminal, \*(UA will
6558 temporarily release the terminal to it
6559 .Pf ( Cd needsterminal ) .
6560 This flag is mutual exclusive with
6562 will only be used in interactive mode and implies
6566 Request creation of a zero-sized temporary file, the absolute pathname
6567 of which will be made accessable via the environment variable
6568 .Ev NAIL_FILENAME_TEMPORARY
6569 .Pf ( Cd x-mailx-tmpfile ) .
6570 If this trigger is given twice then the file will be unlinked
6571 automatically by \*(UA when the command loop is entered again at latest
6572 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6573 (Don't use this for asynchronous handlers.)
6576 Normally the MIME part content is passed to the handler via standard
6577 input; if this flag is set then the data will instead be written into
6578 .Ev NAIL_FILENAME_TEMPORARY
6579 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6580 the creation of which is implied; note however that in order to cause
6581 deletion of the temporary file you still have to use two plus signs
6586 To avoid ambiguities with normal shell command content you can use
6587 another at-sign to forcefully terminate interpretation of remaining
6589 (Any character not in this list will have the same effect.)
6593 Some information about the MIME part to be displayed is embedded into
6594 the environment of the shell command:
6597 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6600 The MIME content-type of the part, if known, the empty string otherwise.
6603 .It Ev NAIL_CONTENT_EVIDENCE
6605 .Va mime-counter-evidence
6606 includes the carry-around-bit (2), then this will be set to the detected
6607 MIME content-type; not only then identical to
6608 .Ev \&\&NAIL_CONTENT
6612 .It Ev NAIL_FILENAME
6613 The filename, if any is set, the empty string otherwise.
6616 .It Ev NAIL_FILENAME_GENERATED
6620 .It Ev NAIL_FILENAME_TEMPORARY
6621 If temporary file creation has been requested through the command prefix
6622 this variable will be set and contain the absolute pathname of the
6627 The temporary directory that \*(UA uses.
6628 Usually identical to
6630 but guaranteed to be set and usable by child processes;
6631 to ensure the latter condition for
6638 .It Va pipe-EXTENSION
6639 This is identical to
6640 .Va pipe-TYPE/SUBTYPE
6643 (normalized to lowercase using character mappings of the ASCII charset)
6644 names a file extension, e.g.,
6646 Handlers registered using this method take precedence.
6649 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6650 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6651 The only possible value as of now is
6653 which is thus the default.
6656 .Mx Va pop3-bulk-load
6657 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6658 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6659 the messages, and only requests the message bodies on user request.
6660 For the POP3 protocol this means that the message headers will be
6662 If this option is set then \*(UA will download only complete messages
6663 from the given POP3 server(s) instead.
6665 .Mx Va pop3-keepalive
6666 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6667 \*(OP POP3 servers close the connection after a period of inactivity;
6668 the standard requires this to be at least 10 minutes,
6669 but practical experience may vary.
6670 Setting this variable to a numeric value greater than
6674 command to be sent each value seconds if no other operation is performed.
6677 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6678 \*(BO\*(OP Unless this variable is set the
6680 authentication method will be used when connecting to a POP3 server that
6684 is that the password is not sent in clear text over the wire and that
6685 only a single packet is sent for the user/password tuple.
6687 .Va pop3-no-apop-HOST
6690 .Mx Va pop3-use-starttls
6691 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6692 \*(BO\*(OP Causes \*(UA to issue a
6694 command to make an unencrypted POP3 session SSL/TLS encrypted.
6695 This functionality is not supported by all servers,
6696 and is not used if the session is already encrypted by the POP3S method.
6698 .Va pop3-use-starttls-HOST
6702 .It Va print-alternatives
6703 \*(BO When a MIME message part of type
6704 .Ql multipart/alternative
6705 is displayed and it contains a subpart of type
6707 other parts are normally discarded.
6708 Setting this variable causes all subparts to be displayed,
6709 just as if the surrounding part was of type
6710 .Ql multipart/mixed .
6714 The string shown when a command is accepted.
6715 Prompting may be prevented by setting this to the null string
6717 .Pf no Va prompt ) .
6718 If a value is assigned the following \*(UA specific additional sequences
6725 is set, in which case it expands to
6729 is the default value of
6732 which will expand to
6734 if the last command failed and to
6738 which will expand to the name of the currently active
6740 if any, and to the empty string otherwise, and
6742 which will expand to the name of the currently active mailbox.
6743 (Note that the prompt buffer is size-limited, excess is cut off.)
6749 to encapsulate the expansions of the
6753 escape sequences as necessary to correctly display bidirectional text,
6754 this is not true for the final string that makes up
6756 as such, i.e., real BIDI handling is not supported.
6760 \*(BO Suppresses the printing of the version when first invoked.
6764 If set, \*(UA starts a replying message with the original message
6765 prefixed by the value of the variable
6767 Normally, a heading consisting of
6768 .Dq Fromheaderfield wrote:
6769 is put before the quotation.
6774 variable, this heading is omitted.
6777 is assigned, the headers selected by the
6778 .Ic ignore Ns / Ns Ic retain
6779 commands are put above the message body,
6782 acts like an automatic
6788 is assigned, all headers are put above the message body and all MIME
6789 parts are included, making
6791 act like an automatic
6794 .Va quote-as-attachment .
6797 .It Va quote-as-attachment
6798 \*(BO Add the original message in its entirety as a
6800 MIME attachment when replying to a message.
6801 Note this works regardless of the setting of
6806 \*(OP Can be set in addition to
6808 Setting this turns on a more fancy quotation algorithm in that leading
6809 quotation characters are compressed and overlong lines are folded.
6811 can be set to either one or two (space separated) numeric values,
6812 which are interpreted as the maximum (goal) and the minimum line length,
6813 respectively, in a spirit rather equal to the
6815 program, but line-, not paragraph-based.
6816 If not set explicitly the minimum will reflect the goal algorithmically.
6817 The goal can't be smaller than the length of
6819 plus some additional pad.
6820 Necessary adjustments take place silently.
6823 .It Va recipients-in-cc
6824 \*(BO On group replies, specify only the sender of the original mail in
6826 and mention the other recipients in the secondary
6828 By default all recipients of the original mail will be addressed via
6833 If defined, gives the pathname of the folder used to record all outgoing
6835 If not defined, then outgoing mail is not saved.
6836 When saving to this folder fails the message is not sent,
6837 but instead saved to
6841 .It Va record-resent
6842 \*(BO If both this variable and the
6849 commands save messages to the
6851 folder as it is normally only done for newly composed messages.
6854 .It Va reply-in-same-charset
6855 \*(BO If this variable is set \*(UA first tries to use the same
6856 character set of the original message for replies.
6857 If this fails, the mechanism described in
6858 .Sx "Character sets"
6859 is evaluated as usual.
6862 .It Va reply_strings
6863 Can be set to a comma-separated list of (case-insensitive according to
6864 ASCII rules) strings which shall be recognized in addition to the
6867 reply message indicators \(en builtin are
6869 which is mandated by RFC 5322, as well as the german
6874 A list of addresses to put into the
6876 field of the message header.
6877 Members of this list are handled as if they were in the
6882 .It Va reply-to-honour
6885 header is honoured when replying to a message via
6889 This is a quadoption; if set without a value it defaults to
6893 .It Va rfc822-body-from_
6894 \*(BO This variable can be used to force displaying a so-called
6896 line for messages that are embedded into an envelope mail via the
6898 MIME mechanism, for more visual convenience.
6902 \*(BO Enable saving of (partial) messages in
6904 upon interrupt or delivery error.
6908 When \*(UA initially displays the message headers it determines the
6909 number to display by looking at the speed of the terminal.
6910 The faster the terminal, the more will be shown.
6911 This option specifies the number to use and overrides the calculation.
6912 This number is also used for scrolling with the
6915 Overall screen dimensions and pager usage is influenced by the
6916 environment variables
6924 .It Va searchheaders
6925 \*(BO Expand message-list specifiers in the form
6927 to all messages containing the substring
6931 The string search is case insensitive.
6935 \*(OP A comma-separated list of character set names that can be used in
6936 outgoing internet mail.
6937 The value of the variable
6939 is automatically appended to this list of character-sets.
6940 If no character set conversion capabilities are compiled into \*(UA then
6941 the only supported charset is
6944 .Va sendcharsets-else-ttycharset
6945 and refer to the section
6946 .Sx "Character sets"
6947 for the complete picture of character set conversion in \*(UA.
6950 .It Va sendcharsets-else-ttycharset
6951 \*(BO\*(OP If this variable is set, but
6953 is not, then \*(UA acts as if
6955 had been set to the value of the variable
6957 In effect this combination passes through the message data in the
6958 character set of the current locale (given that
6960 hasn't been set manually), i.e., without converting it to the
6962 fallback character set.
6963 Thus, mail message text will be in ISO-8859-1 encoding when send from
6964 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
6966 If no character set conversion capabilities are available in \*(UA then
6967 the only supported character set is
6972 An address that is put into the
6974 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6975 responsible for the actual transmission of the message.
6976 This field should normally not be used unless the
6978 field contains more than one address, on which case it is required.
6981 address is handled as if it were in the
6987 To use an alternate mail transport agent (MTA),
6988 set this option to the full pathname of the program to use.
6989 It may be necessary to set
6990 .Va sendmail-progname
6993 The MTA will be passed command line arguments from several possible
6994 sources: from the variable
6995 .Va sendmail-arguments
6996 if set, from the command line if given and the variable
6999 Argument processing of the MTA will be terminated with a
7003 The otherwise occurring implicit usage of the following MTA command line
7004 arguments can be disabled by setting the boolean option
7005 .Va sendmail-no-default-arguments
7006 (which will also disable passing
7010 (for not treating a line with only a dot
7012 character as the end of input),
7020 option is set); in conjunction with the
7022 command line option \*(UA will also pass
7028 .It Va sendmail-arguments
7029 Arguments to pass through to the Mail-Transfer-Agent can be given via
7031 The content of this variable will be split up in a vector of arguments
7032 which will be joined onto other possible MTA options:
7034 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7037 .It Va sendmail-no-default-arguments
7038 \*(BO Unless this option is set \*(UA will pass some well known
7039 standard command line options to the defined
7041 program, see there for more.
7044 .It Va sendmail-progname
7045 Many systems use a so-called
7047 environment to ensure compatibility with
7049 This works by inspecting the name that was used to invoke the mail
7051 If this variable is set then the mailwrapper (the program that is
7052 actually executed when calling
7054 will treat its contents as that name.
7060 \*(BO When sending a message wait until the MTA (including the builtin
7061 SMTP one) exits before accepting further commands.
7063 with this variable set errors reported by the MTA will be recognizable!
7064 If the MTA returns a non-zero exit status,
7065 the exit status of \*(ua will also be non-zero.
7069 \*(BO Setting this option causes \*(UA to start at the last message
7070 instead of the first one when opening a mail folder.
7074 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7075 address in the header field summary and in message specifications.
7079 \*(BO Causes the recipient of the message to be shown in the header
7080 summary if the message was sent by the user.
7084 A string for use with the
7090 A string for use with the
7096 Must correspond to the name of a readable file if set.
7097 The file's content is then appended to each singlepart message
7098 and to the first part of each multipart message.
7099 Be warned that there is no possibility to edit the signature for an
7103 .It Va skipemptybody
7104 \*(BO If an outgoing message does not contain any text in its first or
7105 only message part, do not send it but discard it silently (see also the
7111 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7112 Enhanced Mail) format for verification of S/MIME signed messages.
7115 .It Va smime-ca-file
7116 \*(OP Specifies a file with CA certificates in PEM format for
7117 verification of S/MIME signed messages.
7120 .It Va smime-cipher-USER@HOST , smime-cipher
7121 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7122 messages (for the specified account).
7123 RFC 5751 mandates a default of
7126 Possible values are (case-insensitive and) in decreasing cipher strength:
7134 (DES EDE3 CBC, 168 bits; default if
7136 isn't available) and
7140 The actually available cipher algorithms depend on the cryptographic
7141 library that \*(UA uses.
7142 \*(OP Support for more cipher algorithms may be available through
7143 dynamic loading via, e.g.,
7144 .Xr EVP_get_cipherbyname 3
7145 (OpenSSL) if \*(UA has been compiled to support this.
7148 .It Va smime-crl-dir
7149 \*(OP Specifies a directory that contains files with CRLs in PEM format
7150 to use when verifying S/MIME messages.
7153 .It Va smime-crl-file
7154 \*(OP Specifies a file that contains a CRL in PEM format to use when
7155 verifying S/MIME messages.
7158 .It Va smime-encrypt-USER@HOST
7159 \*(OP If this variable is set, messages send to the given receiver are
7160 encrypted before sending.
7161 The value of the variable must be set to the name of a file that
7162 contains a certificate in PEM format.
7164 If a message is sent to multiple recipients,
7165 each of them for whom a corresponding variable is set will receive an
7166 individually encrypted message;
7167 other recipients will continue to receive the message in plain text
7169 .Va smime-force-encryption
7171 It is recommended to sign encrypted messages, i.e., to also set the
7176 .It Va smime-force-encryption
7177 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7180 .It Va smime-no-default-ca
7181 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7186 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7187 and include the user's certificate as a MIME attachment.
7188 Signing a message enables a recipient to verify that the sender used
7189 a valid certificate,
7190 that the email addresses in the certificate match those in the message
7191 header and that the message content has not been altered.
7192 It does not change the message text,
7193 and people will be able to read the message as usual.
7195 .Va smime-sign-cert , smime-sign-include-certs
7197 .Va smime-sign-message-digest .
7199 .Mx Va smime-sign-cert
7200 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7201 \*(OP Points to a file in PEM format.
7202 For the purpose of signing and decryption this file needs to contain the
7203 user's private key as well as his certificate.
7207 is always derived from the value of
7209 (or, if that contains multiple addresses,
7211 For the purpose of encryption the recipient's public encryption key
7212 (certificate) is expected; the command
7214 can be used to save certificates of signed messages (the section
7215 .Sx "Signed and encrypted messages with S/MIME"
7216 gives some details).
7217 This mode of operation is usually driven by the specialized form.
7219 When decrypting messages the account is derived from the recipient
7224 of the message, which are searched for addresses for which such
7226 \*(UA always uses the first address that matches,
7227 so if the same message is sent to more than one of the user's addresses
7228 using different encryption keys, decryption might fail.
7230 .Mx Va smime-sign-include-certs
7231 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7232 \*(OP If used, this is supposed to a consist of a comma-separated list
7233 of files, each of which containing a single certificate in PEM format to
7234 be included in the S/MIME message in addition to the
7237 This is most useful for long certificate chains if it is desired to aid
7238 the receiving party's verification process.
7239 Note that top level certificates may also be included in the chain but
7240 don't play a role for verification.
7242 .Va smime-sign-cert .
7243 Remember that for this
7245 refers to the variable
7247 (or, if that contains multiple addresses,
7250 .Mx Va smime-sign-message-digest
7251 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7252 \*(OP Specifies the message digest to use when signing S/MIME messages.
7253 RFC 5751 mandates a default of
7255 Possible values are (case-insensitive and) in decreasing cipher strength:
7263 The actually available message digest algorithms depend on the
7264 cryptographic library that \*(UA uses.
7265 \*(OP Support for more message digest algorithms may be available
7266 through dynamic loading via, e.g.,
7267 .Xr EVP_get_digestbyname 3
7268 (OpenSSL) if \*(UA has been compiled to support this.
7269 Remember that for this
7271 refers to the variable
7273 (or, if that contains multiple addresses,
7279 \*(OP Normally \*(UA invokes the program defined via
7281 to transfer messages, as described in
7282 .Sx "On sending mail, and non-interactive mode" .
7285 variable will instead cause SMTP network connections be made to the
7286 server specified therein in order to directly submit the message.
7287 \*(UA knows about three different
7288 .Dq SMTP protocols :
7290 .Bl -bullet -compact
7292 The plain SMTP protocol (RFC 5321) that normally lives on the
7293 server port 25 and requires setting the
7294 .Va smtp-use-starttls
7295 variable to enter a SSL/TLS encrypted session state.
7296 Assign a value like \*(IN
7297 .Ql [smtp://][user[:password]@]server[:port]
7299 .Ql [smtp://]server[:port] )
7300 to choose this protocol.
7302 Then the so-called SMTPS which is supposed to live on server port 465
7303 and is automatically SSL/TLS secured.
7304 Unfortunately it never became a standardized protocol and may thus not
7305 be supported by your hosts network service database
7306 \(en in fact the port number has already been reassigned to other
7309 SMTPS is nonetheless a commonly offered protocol and thus can be
7310 chosen by assigning a value like \*(IN
7311 .Ql smtps://[user[:password]@]server[:port]
7313 .Ql smtps://server[:port] ) ;
7314 due to the mentioned problems it is usually necessary to explicitly
7319 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7320 lives on server port 587 and is practically identically to the SMTP
7321 protocol from \*(UA's point of view beside that; it requires setting the
7322 .Va smtp-use-starttls
7323 variable to enter a SSL/TLS secured session state.
7324 Assign a value like \*(IN
7325 .Ql submission://[user[:password]@]server[:port]
7327 .Ql submission://server[:port] ) .
7330 For more on credentials etc. please see
7331 .Sx "On URL syntax and credential lookup" .
7332 The SMTP transfer is executed in a child process, which runs
7333 asynchronously unless either the
7338 If it receives a TERM signal, it will abort and save the message to
7343 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7344 \*(OP Variable chain that sets the SMTP authentication method.
7351 as well as the \*(OPal methods
7357 method doesn't need any user credentials,
7359 requires a user name and all other methods require a user name and
7367 .Va smtp-auth-password
7369 .Va smtp-auth-user ) .
7374 .Va smtp-auth-USER@HOST :
7375 may override dependend on sender address in the variable
7378 .It Va smtp-auth-password
7379 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7380 If the authentication method requires a password, but neither
7381 .Va smtp-auth-password
7383 .Va smtp-auth-password-USER@HOST
7385 \*(UA will ask for a password on the user's terminal.
7387 .It Va smtp-auth-password-USER@HOST
7389 .Va smtp-auth-password
7390 for specific values of sender addresses, dependent upon the variable
7393 .It Va smtp-auth-user
7394 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7395 If the authentication method requires a user name, but neither
7398 .Va smtp-auth-user-USER@HOST
7400 \*(UA will ask for a user name on the user's terminal.
7402 .It Va smtp-auth-user-USER@HOST
7405 for specific values of sender addresses, dependent upon the variable
7409 .It Va smtp-hostname
7410 \*(IN Normally \*(UA uses the variable
7412 to derive the necessary
7414 information to issue a
7419 can be used to use the
7421 from the SMTP account
7428 from the content of this variable (or, if that is the empty string,
7430 or the local hostname as a last resort).
7431 This often allows using an address that is itself valid but hosted by
7432 a provider other than which (in
7434 is about to send the message.
7435 Setting this variable also influences the generated
7438 .Mx Va smtp-use-starttls
7439 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7440 \*(BO\*(OP Causes \*(UA to issue a
7442 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7443 transport layer security.
7447 .It Va spam-interface
7448 \*(OP In order to use any of the spam-related commands (like, e.g.,
7450 the desired spam interface must be defined by setting this variable.
7451 Please refer to the manual section
7453 for the complete picture of spam handling in \*(UA.
7454 All or none of the following interfaces may be available:
7456 .Bl -tag -width ".It Ql _ilte_"
7462 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7464 Different to the generic filter interface \*(UA will automatically add
7465 the correct arguments for a given command and has the necessary
7466 knowledge to parse the program's output.
7469 will have been compiled into the \*(UA binary if
7474 Shall it be necessary to define a specific connection type (rather than
7475 using a configuration file for that), the variable
7477 can be used as in, e.g.,
7478 .Ql -d server.example.com -p 783 .
7479 It is also possible to specify a per-user configuration via
7481 Note that this interface doesn't inspect the
7483 flag of a message for the command
7487 \*(UA will directly communicate with the
7493 stream socket as specified in
7495 It is possible to specify a per-user configuration via
7499 generic spam filter support via freely configurable hooks.
7500 This interface is ment for programs like
7504 and requires according behaviour in respect to the hooks' exit
7505 status for at least the command
7508 meaning a message is spam,
7512 for unsure and any other return value indicating a hard error);
7513 since the hooks can include shell code snippets diverting behaviour
7514 can be intercepted as necessary.
7516 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7519 .Va spamfilter-spam ;
7522 contains examples for some programs.
7523 The process environment of the hooks will have the variables
7524 .Ev NAIL_TMPDIR , TMPDIR
7526 .Ev NAIL_FILENAME_GENERATED
7528 Note that spam score support for
7530 isn't supported unless the \*(OPtional regular expression support is
7532 .Va spamfilter-rate-scanscore
7539 \*(OP Messages that exceed this size won't be passed through to the
7541 .Va spam-interface .
7542 The default is 420000 bytes.
7545 .It Va spamc-command
7546 \*(OP The path to the
7550 .Va spam-interface .
7551 Note that the path is not expanded, but used
7553 A fallback path will have been compiled into the \*(UA binary if the
7554 executable had been found during compilation.
7557 .It Va spamc-arguments
7558 \*(OP Even though \*(UA deals with most arguments for the
7561 automatically, it may at least sometimes be desirable to specifiy
7562 connection-related ones via this variable, e.g.,
7563 .Ql -d server.example.com -p 783 .
7567 \*(OP Specify a username for per-user configuration files for the
7569 .Va spam-interface .
7570 If this is set to the empty string then \*(UA will use the name of the
7576 \*(OP Specify the path of the
7578 domain socket on which
7580 listens for connections for the
7582 .Va spam-interface .
7583 Note that the path is not expanded, but used
7588 \*(OP Specify a username for per-user configuration files for the
7590 .Va spam-interface .
7591 If this is set to the empty string then \*(UA will use the name of the
7600 .It Va spamfilter-ham , spamfilter-noham , \
7601 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7602 \*(OP Command and argument hooks for the
7604 .Va spam-interface .
7607 contains examples for some programs.
7610 .It Va spamfilter-rate-scanscore
7611 \*(OP Because of the generic nature of the
7614 spam scores are not supported for it by default, but if the \*(OPtional
7615 regular expression support is available then setting this variable can
7616 be used to overcome this restriction.
7617 It is interpreted as follows: first a number (digits) is parsed that
7618 must be followed by a semicolon
7620 and an extended regular expression.
7621 Then the latter is used to parse the first output line of the
7623 hook, and, in case the evaluation is successful, the group that has been
7624 specified via the number is interpreted as a floating point scan score.
7628 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7629 Enhanced Mail) for verification of of SSL/TLS server certificates.
7631 .Xr SSL_CTX_load_verify_locations 3
7632 for more information.
7636 \*(OP Specifies a file with CA certificates in PEM format for
7637 verification of SSL/TLS server certificates.
7639 .Xr SSL_CTX_load_verify_locations 3
7640 for more information.
7643 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7644 \*(OP Variable chain that sets the file name for a SSL/TLS client
7645 certificate required by some servers.
7646 This is a direct interface to the
7650 function of the OpenSSL library, if available.
7652 .Mx Va ssl-cipher-list
7653 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7654 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7655 This is a direct interface to the
7659 function of the OpenSSL library, if available; see
7661 for more information.
7662 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7664 specific cipher (protocol standards ship with a list of acceptable
7665 ciphers), possibly cramped to what the actually used SSL/TLS library
7666 supports \(en the manual section
7667 .Sx "An example configuration"
7668 also contains a SSL/TLS use case.
7671 .It Va ssl-config-file
7672 \*(OP If this variable is set \*(UA will call
7673 .Xr CONF_modules_load_file 3
7674 to allow OpenSSL to be configured according to the host system wide
7676 If a non-empty value is given then this will be used to specify the
7677 configuration file to be used instead of the global OpenSSL default;
7678 note that in this case it is an error if the file cannot be loaded.
7679 The application name will always be passed as
7684 \*(OP Specifies a file that contains a CRL in PEM format to use when
7685 verifying SSL/TLS server certificates.
7689 \*(OP Specifies a directory that contains files with CRLs in PEM format
7690 to use when verifying SSL/TLS server certificates.
7693 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7694 \*(OP Variable chain that sets the file name for the private key of
7695 a SSL/TLS client certificate.
7696 If unset, the name of the certificate file is used.
7697 The file is expected to be in PEM format.
7698 This is a direct interface to the
7702 function of the OpenSSL library, if available.
7705 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7707 \*(OB Please use the newer and more flexible
7709 instead: if both values are set,
7711 will take precedence!
7712 Can be set to the following values, the actually used
7714 specification to which it is mapped is shown in parenthesis:
7716 .Pf ( Ql -ALL, TLSv1.2 ) ,
7718 .Pf ( Ql -ALL, TLSv1.1 ) ,
7720 .Pf ( Ql -ALL, TLSv1 )
7723 .Pf ( Ql -ALL, SSLv3 ) ;
7728 and thus includes the SSLv3 protocol.
7729 Note that SSLv2 is no longer supported at all.
7732 .It Va ssl-no-default-ca
7733 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7737 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7738 \*(OP Specify the used SSL/TLS protocol.
7739 This is a direct interface to the
7743 function of the OpenSSL library, if available;
7744 otherwise an \*(UA internal parser is used which understands the
7745 following subset of (case-insensitive) command strings:
7751 as well as the special value
7753 Multiple specifications may be given via a comma-separated list which
7754 ignores any whitespace.
7757 plus prefix will enable a protocol, a
7759 minus prefix will disable it, so that
7761 will enable only the TLSv1.2 protocol.
7763 It depends upon the used TLS/SSL library which protocols are actually
7764 supported and which protocols are used if
7766 is not set, but note that SSLv2 is no longer supported at all and
7768 Especially for older protocols explicitly securing
7770 may be worthwile, see
7771 .Sx "An example configuration" .
7775 \*(OP Gives the pathname to an entropy daemon socket, see
7777 Not all SSL/TLS libraries support this.
7780 .It Va ssl-rand-file
7781 \*(OP Gives the filename to a file with random entropy data, see
7782 .Xr RAND_load_file 3 .
7783 If this variable is not set, or set to the empty string, or if the
7784 filename expansion failed, then
7785 .Xr RAND_file_name 3
7786 will be used to create the filename if, and only if,
7788 documents that the SSL PRNG is not yet sufficiently seeded.
7789 If \*(UA successfully seeded the SSL PRNG then it'll update the file via
7790 .Xr RAND_write_file 3 .
7791 This variable is only used if
7793 is not set (or not supported by the SSL/TLS library).
7796 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7797 \*(OP Variable chain that sets the action to be performed if an error
7798 occurs during SSL/TLS server certificate validation.
7799 Valid (case-insensitive) values are
7801 (fail and close connection immediately),
7803 (ask whether to continue on standard input),
7805 (show a warning and continue),
7807 (do not perform validation).
7813 If only set without an assigned value, then this option inhibits the
7818 header fields that include obvious references to \*(UA.
7819 There are two pitfalls associated with this:
7820 First, the message id of outgoing messages is not known anymore.
7821 Second, an expert may still use the remaining information in the header
7822 to track down the originating mail user agent.
7827 suppression doesn't occur.
7832 (\*(OP) This specifies a comma-separated list of
7837 .Sx "On terminal control and line editor" ,
7838 escape commas with backslash) to be used to overwrite or define entries.
7840 that this variable will only be queried once at program startup and can
7841 thus only be specified in resource files or on the command line.
7844 String capabilities form
7846 pairs and are expected unless noted otherwise.
7847 Numerics have to be notated as
7849 where the number is expected in normal decimal notation.
7850 Finally, booleans don't have any value but indicate a true or false
7851 state simply by being defined or not; this indeed means that \*(UA
7852 doesn't support undefining a boolean that normally exists.
7853 The following example defines that the terminal has 256 colours:
7855 .Bd -literal -offset indent
7856 set termcap="colors=256"
7860 Keycodes can easily be detected with the command
7862 by running it on an interactive terminal via
7866 command line option if available) and pressing some keys: here
7874 (actually a visualized numeric where
7876 stands for 1 etc.; in fact: the numeric value of
7878 in the US-ASCII character set bitwise XORd with
7881 .Ql $ echo $((0x41 ^ 0x40)) .
7884 and other control characters have to be notated as shell-style
7885 escape sequences, e.g.,
7895 The following terminal capabilities are or may be meaningful for the
7896 operation of the builtin line editor or \*(UA in general:
7899 .Bl -tag -compact -width yay
7901 .It Cd colors Ns \0or Cd Co
7903 numeric capability specifying the maximum number of colours.
7904 Note that \*(UA doesn't actually care about the terminal beside that,
7905 but always emits ANSI/ISO 6429 escape sequences for producing the
7906 colour and font attributes.
7909 .It Cd rmcup Ns \0or Cd te Ns \0/ Cd smcup Ns \0or Cd ti
7913 respectively: exit and enter the alternative screen
7915 effectively turning \*(UA into a fullscreen application.
7916 To disable that, set (at least) one to the empty string.
7918 .It Cd smkx Ns \0or Cd ks Ns \0/ Cd rmkx Ns \0or Cd ke
7922 respectively: enable and disable the keypad.
7923 This is always enabled if available, because it seems even keyboards
7924 without keypads generate other key codes for, e.g., cursor keys in that
7925 case, and only if enabled we see the codes that we are interested in.
7927 .It Cd ed Ns \0or Cd cd
7931 .It Cd clear Ns \0or Cd cl
7933 clear the screen and home cursor.
7934 (Will be simulated via
7939 .It Cd home Ns \0or Cd ho
7944 .It Cd el Ns \0or Cd ce
7946 clear to the end of line.
7947 (Will be simulated via
7949 plus repititions of space characters.)
7951 .It Cd hpa Ns \0or Cd ch
7952 .Cd column_address :
7953 move the cursor (to the given column parameter) in the current row.
7954 (Will be simulated via
7960 .Cd carriage_return :
7961 move to the first column in the current row.
7962 The default builtin fallback is
7965 .It Cd cub1 Ns \0or Cd le
7967 move the cursor left one space (non-destructively).
7968 The default builtin fallback is
7971 .It Cd cuf1 Ns \0or Cd nd
7973 move the cursor right one space (non-destructively).
7974 The default builtin fallback is
7976 which is used by most terminals.
7985 .It Va termcap-disable
7986 \*(OP Disable any interaction with a terminal control library.
7987 If set only some generic fallback builtins and possibly the content of
7989 describe the terminal to \*(UA.
7991 that this variable will only be queried once at program startup and can
7992 thus only be specified in resource files or on the command line.
7996 If defined, gives the number of lines of a message to be displayed
7999 normally, the first five lines are printed.
8003 The character set of the terminal \*(UA operates on,
8004 and the one and only supported character set that \*(UA can use if no
8005 character set conversion capabilities have been compiled into it,
8006 in which case it defaults to ISO-8859-1 unless it can deduce a value
8010 Refer to the section
8011 .Sx "Character sets"
8012 for the complete picture about character sets.
8015 .It Va user-HOST , user
8016 \*(IN Variable chain that sets a global fallback user name, which is
8017 used in case none has been given in the protocol and account-specific
8019 This variable defaults to the value of the first of
8023 that is set (the former being SystemV and POSIX standard, the latter BSD).
8027 \*(BO Setting this option enables upward compatibility with \*(UA
8028 version 15.0 in respect to which configuration options are available and
8029 how they are handled.
8030 This manual uses \*(IN and \*(OU to refer to the new and the old way of
8031 doing things, respectively.
8035 \*(BO Setting this option, also controllable via the command line option
8037 causes \*(UA to be more verbose, e.g., it will display obsoletion
8038 warnings and SSL/TLS certificate chains.
8039 Even though marked \*(BO this option may be set twice in order to
8040 increase the level of verbosity even more, in which case even details of
8041 the actual message delivery and protocol conversations are shown.
8044 is sufficient to disable verbosity as such.
8050 .It Va version , version-major , version-minor , version-update
8051 \*(RO \*(UA version information: the first variable contains a string
8052 containing the complete version identification \(en this is identical to
8053 the output of the command
8055 The latter three contain only digits: the major, minor and update
8059 .It Va writebackedited
8060 If this variable is set messages modified using the
8064 commands are written back to the current folder when it is quit;
8065 it is only honoured for writable folders in MBOX format, though.
8066 Note that the editor will be pointed to the raw message content in that
8067 case, i.e., neither MIME decoding nor decryption will have been
8068 performed, and proper RFC 4155
8070 quoting of newly added or edited content is also left as an excercise to
8074 .\" }}} (INTERNAL VARIABLES)
8077 .\" .Sh ENVIRONMENT {{{
8081 .Dq environment variable
8082 should be considered an indication that the following variables are
8083 either standardized as being vivid parts of process environments, or
8084 are commonly found in there.
8085 The process environment is inherited from the
8087 once \*(UA is started, and unless otherwise explicitly noted variables
8088 in there integrate into the normal handling of
8089 .Sx "INTERNAL VARIABLES" ,
8090 from \*(UAs point of view, i.e., they can be
8092 as such in resource files and need not necessarily come from the process
8093 environment and be managed via
8097 E.g., the following example, applicable to a POSIX shell, sets the
8099 environment variable for \*(UA only, and beforehand exports the
8101 in order to affect any further processing in the running shell:
8103 .Bd -literal -offset indent
8104 $ EDITOR="vim -u ${HOME}/.vimrc"
8106 $ COLUMNS=80 \*(ua -R
8109 .Bl -tag -width ".It Ev _AILR_"
8112 The user's preferred width in column positions for the terminal screen
8114 Queried and used once on program startup.
8118 The name of the file to use for saving aborted messages if
8120 is set; this defaults to
8128 Pathname of the text editor to use in the
8132 .Sx "TILDE ESCAPES" .
8133 A default editor is used if this value is not defined.
8137 The user's home directory.
8138 This variable is only used when it resides in the process environment.
8141 to update the value at runtime.
8148 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
8152 .Sx "Character sets" .
8156 The user's preferred number of lines on a page or the vertical screen
8157 or window size in lines.
8158 Queried and used once on program startup.
8162 Pathname of the directory lister to use in the
8164 command when operating on local mailboxes.
8167 (path search through
8172 Force identification as the given user, i.e., identical to the
8174 command line option.
8175 This variable is standardized and therefore used in preference to the
8178 it is only used when it resides in the process environment.
8179 \*(ID The variable can be updated at runtime via
8181 but without having an effect on \*(UA itself.
8185 Is used as the user's mailbox, if set.
8186 Otherwise, a system-dependent default is used.
8187 Supports a logical subset of the special conventions that are documented
8196 \*(OP Overrides the default path search for
8197 .Sx "The Mailcap files" ,
8198 which is defined in the standard RFC 1524 as
8199 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
8200 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8201 (\*(UA makes it a configuration option, however.)
8202 Note this is not a search path, but a path search.
8206 Is used as a startup file instead of
8209 When \*(UA scripts are invoked on behalf of other users,
8210 either this variable should be set to
8214 command line option should be used in order to avoid side-effects from
8215 reading their configuration files.
8216 This variable is only used when it resides in the process environment.
8220 The name of the user's mbox file.
8221 A logical subset of the special conventions that are documented for the
8226 The fallback default is
8231 Traditionally this secondary mailbox is used as the file to save
8232 messages from the system mailbox that have been read.
8234 .Sx "Message states" .
8237 .It Ev NAIL_NO_SYSTEM_RC
8238 If this variable is set then reading of
8240 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8241 had been started up with the option
8243 This variable is only used when it resides in the process environment.
8247 \*(IN\*(OP This variable overrides the default location of the user's
8253 Pathname of the program to use for backing the command
8257 variable enforces usage of a pager for output.
8258 The default paginator is
8260 (path search through
8263 \*(UA inspects the contents of this variable: if its contains the string
8265 then a non-existing environment variable
8272 dependent on whether terminal control support is available and whether
8273 that supports full (alternative) screen mode or not (also see
8274 .Sx "On terminal control and line editor" ) .
8278 will optionally be set to
8285 A list of directories that is searched by the shell when looking for
8286 commands (as such only recognized in the process environment).
8290 The shell to use for the commands
8296 and when starting subprocesses.
8297 A default shell is used if this option is not defined.
8301 \*(OP The terminal type for which output is to be prepared.
8302 For extended colour and font control please refer to
8303 .Sx "Coloured display" ,
8304 and for terminal management in general to
8305 .Sx "On terminal control and line editor" .
8309 Used as directory for temporary files instead of
8312 This variable is only used when it resides in the process environment.
8315 to update the value at runtime.
8319 This variable comes from the BSD world and is only used if the POSIX
8320 standard environment variable
8322 which originates in SysV
8325 Force identification as the given user, i.e., identical to the
8327 command line option.
8328 This variable is only used when it resides in the process environment.
8329 \*(ID The variable can be updated at runtime via
8331 but without having an effect on \*(UA itself.
8335 Pathname of the text editor to use in the
8339 .Sx "TILDE ESCAPES" .
8347 .Bl -tag -width ".It Pa _etc/mime.type_"
8349 File giving initial commands.
8352 System wide initialization file.
8356 \*(OP Personal MIME type handler definition file, see
8357 .Sx "The Mailcap files" .
8358 (RFC 1524 location, the actual path is a configuration option.)
8362 \*(OP System wide MIME type handler definition file, see
8363 .Sx "The Mailcap files" .
8364 (RFC 1524 location, the actual path is a configuration option.)
8367 .It Pa ~/.mime.types
8368 Personal MIME types, see
8369 .Sx "The mime.types files" .
8372 .It Pa /etc/mime.types
8373 System wide MIME types, see
8374 .Sx "The mime.types files" .
8378 \*(IN\*(OP The default location of the users
8380 file \(en the section
8381 .Sx "The .netrc file"
8382 documents the file format.
8385 .\" .Ss "The mime.types files" {{{
8386 .Ss "The mime.types files"
8388 When sending messages \*(UA tries to determine the content type of all
8390 When displaying message content or attachments \*(UA uses the content
8391 type to decide wether it can directly display data or wether it needs to
8392 deal with content handlers.
8393 It learns about MIME types and how to treat them by reading
8395 files, the loading of which can be controlled by setting the variable
8396 .Va mimetypes-load-control .
8399 can also be used to deal with MIME types.)
8401 files have the following syntax:
8404 .Dl type/subtype extension [extension ...]
8409 are strings describing the file contents, and one or multiple
8411 s, separated by whitespace, name the part of a filename starting after
8412 the last dot (of interest).
8413 Comments may be introduced anywhere on a line with a number sign
8415 causing the remaining line to be discarded.
8417 \*(UA also supports an extended, non-portable syntax in specially
8418 crafted files, which can be loaded via the alternative value syntax of
8419 .Va mimetypes-load-control
8420 and prepends an optional
8424 .Dl [type-marker ]type/subtype extension [extension ...]
8427 The following type markers are supported:
8430 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8432 Treat message parts with this content as plain text.
8437 Treat message parts with this content as HTML tagsoup.
8438 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8439 the content as plain text instead.
8443 but instead of falling back to plain text require an explicit content
8444 handler to be defined.
8449 for sending messages:
8451 .Va mime-allow-text-controls ,
8452 .Va mimetypes-load-control .
8453 For reading etc. messages:
8454 .Sx "HTML mail and MIME attachments" ,
8455 .Sx "The Mailcap files" ,
8457 .Va mime-counter-evidence ,
8458 .Va mimetypes-load-control ,
8459 .Va pipe-TYPE/SUBTYPE ,
8460 .Va pipe-EXTENSION .
8463 .\" .Ss "The Mailcap files" {{{
8464 .Ss "The Mailcap files"
8467 .Dq User Agent Configuration Mechanism
8468 which \*(UA \*(OPally supports.
8469 It defines a file format to be used to inform mail user agent programs
8470 about the locally-installed facilities for handling various data
8471 formats, i.e., about commands and how they can be used to display, edit
8472 etc. MIME part contents, as well as a default path search that includes
8473 multiple possible locations of
8477 environment variable that can be used to overwrite that (repeating here
8478 that it is not a search path, but instead a path search specification).
8479 Any existing files will be loaded in sequence, appending any content to
8480 the list of MIME type handler directives.
8484 files consist of a set of newline separated entries.
8485 Comment lines start with a number sign
8487 (in the first column!) and are ignored.
8488 Empty lines are also ignored.
8489 All other lines form individual entries that must adhere to the syntax
8491 To extend a single entry (not comment) its line can be continued on
8492 follow lines if newline characters are
8494 by preceding them with the backslash character
8496 The standard doesn't specify how leading whitespace of follow lines is
8497 to be treated, therefore \*(UA retains it.
8501 entries consist of a number of semicolon
8503 separated fields, and the backslash
8505 character can be used to escape any following character including
8506 semicolon and itself.
8507 The first two fields are mandatory and must occur in the specified
8508 order, the remaining fields are optional and may appear in any order.
8509 Leading and trailing whitespace of content is ignored (removed).
8512 The first field defines the MIME
8514 the entry is about to handle (case-insensitively, and no backslash
8515 escaping is possible in this field).
8516 If the subtype is specified as an asterisk
8518 the entry is ment to match all subtypes of the named type, e.g.,
8520 would match any audio type.
8521 The second field defines the shell command which shall be used to
8523 MIME parts of the given type; it is implicitly called the
8530 shell commands message (MIME part) data is passed via standard input
8531 unless the given shell command includes one or more instances of the
8534 in which case these instances will be replaced with a temporary filename
8535 and the data will have been stored in the file that is being pointed to.
8538 shell commands data is assumed to be generated on standard output unless
8539 the given command includes (one ore multiple)
8541 In any case any given
8543 format is replaced with a(n already) properly quoted filename.
8544 Note that when a command makes use of a temporary file via
8546 then \*(UA will remove it again, as if the
8547 .Cd x-mailx-tmpfile ,
8548 .Cd x-mailx-tmpfile-fill
8550 .Cd x-mailx-tmpfile-unlink
8551 flags had been set; see below for more.
8554 The optional fields either define a shell command or an attribute (flag)
8555 value, the latter being a single word and the former being a keyword
8556 naming the field followed by an equals sign
8558 succeeded by a shell command, and as usual for any
8560 content any whitespace surrounding the equals sign will be removed, too.
8561 Optional fields include the following:
8564 .Bl -tag -width textualnewlines
8566 A program that can be used to compose a new body or body part in the
8573 field, but is to be used when the composing program needs to specify the
8575 header field to be applied to the composed data.
8579 A program that can be used to edit a body or body part in the given
8584 A program that can be used to print a message or body part in the given
8589 Specifies a program to be run to test some condition, e.g., the machine
8590 architecture, or the window system in use, to determine whether or not
8591 this mailcap entry applies.
8592 If the test fails, a subsequent mailcap entry should be sought; also see
8593 .Cd x-mailx-test-once .
8595 .It Cd needsterminal
8596 This flag field indicates that the given shell command must be run on
8597 an interactive terminal.
8598 \*(UA will temporarily release the terminal to the given command in
8599 interactive mode, in non-interactive mode this entry will be entirely
8600 ignored; this flag implies
8601 .Cd x-mailx-noquote .
8603 .It Cd copiousoutput
8604 A flag field which indicates that the output of the
8606 command will be an extended stream of textual output that can be
8607 (re)integrated into \*(UA's normal visual display.
8608 It is mutually exclusive with
8611 .Cd x-mailx-always .
8613 .It Cd textualnewlines
8614 A flag field which indicates that this type of data is line-oriented and
8617 all newlines should be converted to canonical form (CRLF) before
8618 encoding, and will be in that form after decoding.
8622 This field gives a file name format, in which
8624 will be replaced by a random string, the joined combination of which
8625 will be used as the filename denoted by
8626 .Ev NAIL_FILENAME_TEMPORARY .
8627 One could specify that a GIF file being passed to an image viewer should
8628 have a name ending in
8631 .Ql nametemplate=%s.gif .
8632 Note that \*(UA ignores the name template unless that solely specifies
8633 a filename suffix that consists of (ASCII) alphabetic and numeric
8634 characters, the underscore and dot only.
8637 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8638 icon to be used to visually denote the presence of this kind of data.
8639 This field is not used by \*(UA.
8642 A textual description that describes this type of data.
8644 .It Cd x-mailx-always
8645 Extension flag field that denotes that the given
8647 command shall be executed even if multiple messages will be displayed
8649 Normally messages which require external viewers that produce output
8650 which doesn't integrate into \*(UA's visual display (i.e., don't have
8652 set) have to be addressed directly and individually.
8653 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8656 .It Cd x-mailx-even-if-not-interactive
8657 An extension flag test field \(em by default handlers without
8659 are entirely ignored in non-interactive mode, but if this flag is set
8660 then their use will be considered.
8661 It is an error if this flag is set for commands that use the flag
8664 .It Cd x-mailx-noquote
8665 An extension flag field that indicates that even a
8668 command shall not be used to generate message quotes
8669 (as it would be by default).
8671 .It Cd x-mailx-async
8672 Extension flag field that denotes that the given
8674 command shall be executed asynchronously, without blocking \*(UA.
8675 Cannot be used in conjunction with
8678 .It Cd x-mailx-test-once
8679 Extension flag which denotes wether the given
8681 command shall be evaluated once only and the (boolean) result be cached.
8682 This is handy if some global unchanging condition is to be queried, like
8683 .Dq running under the X Window System .
8685 .It Cd x-mailx-tmpfile
8686 Extension flag field that requests creation of a zero-sized temporary
8687 file, the name of which is to be placed in the environment variable
8688 .Ev NAIL_FILENAME_TEMPORARY .
8689 It is an error to use this flag with commands that include a
8693 .It Cd x-mailx-tmpfile-fill
8694 Normally the MIME part content is passed to the handler via standard
8695 input; if this flag is set then the data will instead be written into
8697 .Cd x-mailx-tmpfile .
8698 In order to cause deletion of the temporary file you will have to set
8699 .Cd x-mailx-tmpfile-unlink
8701 It is an error to use this flag with commands that include a
8705 .It Cd x-mailx-tmpfile-unlink
8706 Extension flag field that requests that the temporary file shall be
8707 deleted automatically when the command loop is entered again at latest.
8708 (Don't use this for asynchronous handlers.)
8709 It is an error to use this flag with commands that include a
8711 format, or without also setting
8714 .Cd x-mailx-tmpfile-fill .
8716 .It Cd x-mailx-tmpfile-keep
8719 implies the three tmpfile related flags above, but if you want, e.g.,
8721 and deal with the temporary file yourself, you can add in this flag to
8723 .Cd x-mailx-tmpfile-unlink .
8728 The standard includes the possibility to define any number of additional
8729 entry fields, prefixed by
8731 Flag fields apply to the entire
8733 entry \(em in some unusual cases, this may not be desirable, but
8734 differentiation can be accomplished via separate entries, taking
8735 advantage of the fact that subsequent entries are searched if an earlier
8736 one does not provide enough information.
8739 command needs to specify the
8743 command shall not, the following will help out the latter (with enabled
8747 level \*(UA will show informations about handler evaluation):
8749 .Bd -literal -offset indent
8750 application/postscript; ps-to-terminal %s; needsterminal
8751 application/postscript; ps-to-terminal %s; compose=idraw %s
8755 In fields any occurrence of the format string
8757 will be replaced by the
8760 Named parameters from the
8762 field may be placed in the command execution line using
8764 followed by the parameter name and a closing
8767 The entire parameter should appear as a single command line argument,
8768 regardless of embedded spaces; thus:
8770 .Bd -literal -offset indent
8772 Content-type: multipart/mixed; boundary=42
8775 multipart/*; /usr/local/bin/showmulti \e
8776 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8778 # Executed shell command
8779 /usr/local/bin/showmulti multipart/mixed 42
8783 .\" TODO v15: Mailcap: %n,%F
8784 Note that \*(UA doesn't support handlers for multipart MIME parts as
8785 shown in this example (as of today).
8786 \*(UA doesn't support the additional formats
8790 An example file, also showing how to properly deal with the expansion of
8792 which includes any quotes that are necessary to make it a valid shell
8793 argument by itself and thus will cause undesired behaviour when placed
8794 in additional user-provided quotes:
8796 .Bd -literal -offset indent
8798 text/richtext; richtext %s; copiousoutput
8800 text/x-perl; perl -cWT %s
8804 trap "rm -f ${infile}" EXIT\e; \e
8805 trap "exit 75" INT QUIT TERM\e; \e
8807 x-mailx-async; x-mailx-tmpfile-keep
8809 application/*; echo "This is \e"%t\e" but \e
8810 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
8811 copiousoutput; x-mailx-noquote
8816 .Sx "HTML mail and MIME attachments" ,
8817 .Sx "The mime.types files" ,
8820 .Va mime-counter-evidence ,
8821 .Va pipe-TYPE/SUBTYPE ,
8822 .Va pipe-EXTENSION .
8825 .\" .Ss "The .netrc file" {{{
8826 .Ss "The .netrc file"
8830 file contains user credentials for machine accounts.
8831 The default location in the user's
8833 directory may be overridden by the
8835 environment variable.
8836 The file consists of space, tabulator or newline separated tokens.
8837 \*(UA implements a parser that supports a superset of the original BSD
8838 syntax, but users should nonetheless be aware of portability glitches
8839 of that file format, shall their
8841 be usable across multiple programs and platforms:
8844 .Bl -bullet -compact
8846 BSD doesn't support single, but only double quotation marks, e.g.,
8847 .Ql password="pass with spaces" .
8849 BSD (only?) supports escaping of single characters via a backslash
8850 (e.g., a space can be escaped via
8852 in- as well as outside of a quoted string.
8854 BSD doesn't require the final quotation mark of the final user input token.
8856 The original BSD (Berknet) parser also supported a format which allowed
8857 tokens to be separated with commas \(en whereas at least Hewlett-Packard
8858 still seems to support this syntax, \*(UA does not!
8860 As a non-portable extension some widely-used programs support
8861 shell-style comments: if an input line starts, after any amount of
8862 whitespace, with a number sign
8864 then the rest of the line is ignored.
8866 Whereas other programs may require that the
8868 file is accessible by only the user if it contains a
8874 \*(UA will always require these strict permissions.
8878 Of the following list of supported tokens \*(UA only uses (and caches)
8883 At runtime the command
8885 can be used to control \*(UAs
8889 .Bl -tag -width password
8890 .It Cd machine Ar name
8891 The hostname of the entries' machine, lowercase-normalized by \*(UA
8893 Any further file content, until either end-of-file or the occurrence
8898 first-class token is bound (only related) to the machine
8901 As an extension that shouldn't be the cause of any worries
8902 \*(UA supports a single wildcard prefix for
8904 .Bd -literal -offset indent
8905 machine *.example.com login USER password PASS
8906 machine pop3.example.com login USER password PASS
8907 machine smtp.example.com login USER password PASS
8913 .Ql pop3.example.com ,
8917 .Ql local.smtp.example.com .
8918 Note that in the example neither
8919 .Ql pop3.example.com
8921 .Ql smtp.example.com
8922 will be matched by the wildcard, since the exact matches take
8923 precedence (it is however faster to specify it the other way around).
8928 except that it is a fallback entry that is used shall none of the
8929 specified machines match; only one default token may be specified,
8930 and it must be the last first-class token.
8932 .It Cd login Ar name
8933 The user name on the remote machine.
8935 .It Cd password Ar string
8936 The user's password on the remote machine.
8938 .It Cd account Ar string
8939 Supply an additional account password.
8940 This is merely for FTP purposes.
8942 .It Cd macdef Ar name
8944 A macro is defined with the specified
8946 it is formed from all lines beginning with the next line and continuing
8947 until a blank line is (consecutive newline characters are) encountered.
8950 entries cannot be utilized by multiple machines, too, but must be
8951 defined following the
8953 they are intended to be used with.)
8956 exists, it is automatically run as the last step of the login process.
8957 This is merely for FTP purposes.
8964 .\" .Sh EXAMPLES {{{
8967 .\" .Ss "An example configuration" {{{
8968 .Ss "An example configuration"
8970 .Bd -literal -offset indent
8971 # This example assumes v15.0 compatibility mode
8974 # Where are the up-to-date SSL certificates?
8975 #set ssl-ca-dir=/etc/ssl/certs
8976 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8978 # (Since we manage up-to-date ones explicitly, don't use any,
8979 # possibly outdated, default certificates shipped with OpenSSL
8980 set ssl-no-default-ca
8982 # Don't use protocols older than TLS v1.2.
8983 # Change this only when the remote server doesn't support it:
8984 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
8985 # such explicit exceptions, then
8986 set ssl-protocol="-ALL,+TLSv1.2"
8988 # Explicitly define the list of ciphers, which may improve security,
8989 # especially with protocols older than TLS v1.2. See ciphers(1).
8990 # Hint: it is important to include "@STRENGTH": only with it the
8991 # final list will be sorted by algorithm strength.
8992 # This is an example: in reality it is possibly best to only use
8993 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
8994 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
8995 !MD5:!RC4:!EXPORT:@STRENGTH"
8997 # Request strict transport security checks!
8998 set ssl-verify=strict
9000 # Essential setting: select allowed character sets
9001 set sendcharsets=utf-8,iso-8859-1
9003 # A very kind option: when replying to a message, first try to
9004 # use the same encoding that the original poster used herself!
9005 set reply-in-same-charset
9007 # When replying to or forwarding a message the comment and name
9008 # parts of email addresses are removed unless this variable is set
9011 # When sending messages, wait until the Mail-Transfer-Agent finishs.
9012 # Only like this you'll be able to see errors reported through the
9013 # exit status of the MTA (including the builtin SMTP one)!
9016 # Only use builtin MIME types, no mime.types(5) files
9017 set mimetypes-load-control
9019 # Default directory where we act in (relative to $HOME)
9021 # A leading "+" (often) means: under *folder*
9022 # *record* is used to save copies of sent messages
9023 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
9025 # Make "file mymbox" and "file myrec" go to..
9026 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
9028 # Not really optional, e.g., for S/MIME
9029 set from="Your Name <youremail@domain>"
9031 # It may be necessary to set hostname and/or smtp-hostname
9032 # if the "SERVER" of smtp and "domain" of from don't match.
9033 # The `urlencode' command can be used to encode USER and PASS
9034 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
9035 smtp-auth=login/plain... \e
9038 # Never refuse to start into interactive mode, and more
9040 colour-pager crt= \e
9041 followup-to followup-to-honour=ask-yes \e
9042 history-file=+.\*(uahist history-size=-1 history-gabby \e
9043 mime-counter-evidence=0xE \e
9044 prompt='?\e?[\e$ \e@]\e& ' \e
9045 reply-to-honour=ask-yes
9047 # When `p'rinting messages, show only these headers
9048 # (use `P'rint for all headers and `S'how for raw message)
9049 retain date from to cc subject
9051 # Some mailing lists
9052 mlist @xyz-editor.xyz$ @xyzf.xyz$
9053 mlsubscribe ^xfans@xfans.xyz$
9055 # A real life example of a very huge free mail provider
9057 set from="Your Name <youremail@domain>"
9058 # (The plain smtp:// proto is optional)
9059 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
9062 # Here is a pretty large one which does not allow sending mails
9063 # if there is a domain name mismatch on the SMTP protocol level,
9064 # which would bite us if the value of from does not match, e.g.,
9065 # for people who have a sXXXXeforge project and want to speak
9066 # with the mailing list under their project account (in from),
9067 # still sending the message through their normal mail provider
9069 set from="Your Name <youremail@domain>"
9070 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
9071 hostname=yaXXex.com smtp-hostname=
9074 # Create some new commands so that, e.g., `ls /tmp' will..
9085 ghost llS !ls -aFlrS
9088 # We don't support gpg(1) directly yet. But simple --clearsign'd
9089 # message parts can be dealt with as follows:
9092 set pipe-text/plain="@*#++=@\e
9093 < \e"${NAIL_FILENAME_TEMPORARY}\e" awk \e
9094 -v TMPFILE=\e"${NAIL_FILENAME_TEMPORARY}\e" '\e
9096 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
9099 print \e"--- GPG --verify ---\e";\e
9100 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
9101 print \e"--- GPG --verify ---\e";\e
9105 /^-----BEGIN PGP SIGNATURE-----/,\e
9106 /^-----END PGP SIGNATURE-----/ {\e
9116 !printf 'Key IDs to gpg --recv-keys: ';\e
9118 gpg --recv-keys ${keyids};
9124 When storing passwords in
9126 appropriate permissions should be set on this file with
9127 .Ql $ chmod 0600 \*(ur .
9130 is available user credentials can be stored in the central
9132 file instead; e.g., here is a different version of the example account
9133 that sets up SMTP and POP3:
9135 .Bd -literal -offset indent
9137 set from="Your Name <youremail@domain>"
9139 #set agent-shell-lookup="gpg -d .pass.gpg"
9141 set smtp=smtps://smtp.yXXXXx.ru:465 \e
9142 smtp-hostname= hostname=yXXXXx.com
9143 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
9144 ghost xp fi pop3s://pop.yXXXXx.ru
9153 .Bd -literal -offset indent
9154 machine *.yXXXXx.ru login USER password PASS
9159 .Va agent-shell-lookup
9160 is available things could be diversified further by using encrypted
9161 password storage: for this, don't specify
9165 file and instead uncomment the line that defines agent lookup in the
9168 above, then create the encrypted password storage file
9171 .Bd -literal -offset indent
9174 $ eval `gpg-agent --daemon \e
9175 --pinentry-program=/usr/bin/pinentry-curses \e
9176 --max-cache-ttl 99999 --default-cache-ttl 99999`
9180 This configuration should now work just fine (use the
9182 command line option for a(n almost) dry-run):
9185 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
9188 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
9189 .Ss "Signed and encrypted messages with S/MIME"
9191 \*(OP S/MIME provides two central mechanisms:
9192 message signing and message encryption.
9193 A signed message contains some data in addition to the regular text.
9194 The data can be used to verify that the message was sent using a valid
9195 certificate, that the sender's address in the message header matches
9196 that in the certificate, and that the message text has not been altered.
9197 Signing a message does not change its regular text;
9198 it can be read regardless of whether the recipient's software is able to
9202 It is thus usually possible to sign all outgoing messages if so desired.
9203 Encryption, in contrast, makes the message text invisible for all people
9204 except those who have access to the secret decryption key.
9205 To encrypt a message, the specific recipient's public encryption key
9207 It is therefore not possible to send encrypted mail to people unless their
9208 key has been retrieved from either previous communication or public key
9210 A message should always be signed before it is encrypted.
9211 Otherwise, it is still possible that the encrypted message text is
9215 A central concept to S/MIME is that of the certification authority (CA).
9216 A CA is a trusted institution that issues certificates.
9217 For each of these certificates it can be verified that it really
9218 originates from the CA, provided that the CA's own certificate is
9220 A set of CA certificates is usually delivered with OpenSSL and installed
9222 If you trust the source of your OpenSSL software installation,
9223 this offers reasonable security for S/MIME on the Internet.
9225 .Va ssl-no-default-ca
9229 .Va smime-ca-dir . )
9230 In general, a certificate cannot be more secure than the method its CA
9231 certificate has been retrieved with, though.
9232 Thus if you download a CA certificate from the Internet,
9233 you can only trust the messages you verify using that certificate as
9234 much as you trust the download process.
9237 The first thing you need for participating in S/MIME message exchange is
9238 your personal certificate, including a private key.
9239 The certificate contains public information, in particular your name and
9240 your email address(es), and the public key that is used by others to
9241 encrypt messages for you,
9242 and to verify signed messages they supposedly received from you.
9243 The certificate is included in each signed message you send.
9244 The private key must be kept secret.
9245 It is used to decrypt messages that were previously encrypted with your
9246 public key, and to sign messages.
9249 For personal use it is recommended that you get a S/MIME certificate
9250 from one of the major CAs on the Internet using your WWW browser.
9251 Many CAs offer such certificates for free.
9253 .Lk https://www.CAcert.org
9254 which issues client and server certificates to members of their
9255 community for free; their root certificate
9256 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9257 is often not in the default set of trusted CA root certificates, though,
9258 which means you will have to download their root certificate separately
9259 and ensure it is part of our S/MIME certificate validation chain by
9262 or as a vivid member of the
9264 But let's take a step-by-step tour on how to setup S/MIME with
9265 a certificate from CAcert.org despite this situation!
9268 First of all you will have to become a member of the CAcert.org
9269 community, simply by registrating yourself via the web interface.
9270 Once you are, create and verify all email addresses you want to be able
9271 to create signed and encrypted messages for/with using the corresponding
9272 entries of the web interface.
9273 Now ready to create S/MIME certificates, so let's create a new
9274 .Dq client certificate ,
9275 ensure to include all email addresses that should be covered by the
9276 certificate in the following web form, and also to use your name as the
9280 Create a private key and a certificate request on your local computer
9281 (please see the manual pages of the used commands for more in-depth
9282 knowledge on what the used arguments etc. do):
9285 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9288 Afterwards copy-and-paste the content of
9290 into the certificate-request (CSR) field of the web form on the
9291 CAcert.org website (you may need to unfold some
9292 .Dq advanced options
9293 to see the corresponding text field).
9294 This last step will ensure that your private key (which never left your
9295 box) and the certificate belong together (through the public key that
9296 will find its way into the certificate via the certificate-request).
9297 You are now ready and can create your CAcert certified certificate.
9298 Download and store or copy-and-paste it as
9303 In order to use your new S/MIME setup you will have to create
9304 a combined private key/public key (certificate) file:
9307 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9310 This is the file \*(UA will work with.
9311 If you have created your private key with a passphrase then \*(UA will
9312 ask you for it whenever a message is signed or decrypted.
9313 Set the following variables to henceforth use S/MIME (setting
9315 is of interest for verification only):
9317 .Bd -literal -offset indent
9318 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9319 smime-sign-cert=ME@HERE.com.paired \e
9320 smime-sign-message-digest=SHA256 \e
9325 From each signed message you send, the recipient can fetch your
9326 certificate and use it to send encrypted mail back to you.
9327 Accordingly if somebody sends you a signed message, you can do the same,
9330 command to check the validity of the certificate.
9333 Variables of interest for S/MIME signing:
9337 .Va smime-crl-file ,
9338 .Va smime-no-default-ca ,
9340 .Va smime-sign-cert ,
9341 .Va smime-sign-include-certs
9343 .Va smime-sign-message-digest .
9346 After it has been verified save the certificate via
9348 and tell \*(UA that it should use it for encryption for further
9349 communication with that somebody:
9351 .Bd -literal -offset indent
9353 set smime-encrypt-USER@HOST=FILENAME \e
9354 smime-cipher-USER@HOST=AES256
9358 Additional variables of interest for S/MIME en- and decryption:
9361 .Va smime-encrypt-USER@HOST .
9364 You should carefully consider if you prefer to store encrypted messages
9366 If you do, anybody who has access to your mail folders can read them,
9367 but if you do not, you might be unable to read them yourself later if
9368 you happen to lose your private key.
9371 command saves messages in decrypted form, while the
9375 commands leave them encrypted.
9378 Note that neither S/MIME signing nor encryption applies to message
9379 subjects or other header fields yet.
9380 Thus they may not contain sensitive information for encrypted messages,
9381 and cannot be trusted even if the message content has been verified.
9382 When sending signed messages,
9383 it is recommended to repeat any important header information in the
9387 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9388 .Ss "Using CRLs with S/MIME or SSL/TLS"
9390 \*(OP Certification authorities (CAs) issue certificate revocation
9391 lists (CRLs) on a regular basis.
9392 These lists contain the serial numbers of certificates that have been
9393 declared invalid after they have been issued.
9394 Such usually happens because the private key for the certificate has
9396 because the owner of the certificate has left the organization that is
9397 mentioned in the certificate, etc.
9398 To seriously use S/MIME or SSL/TLS verification,
9399 an up-to-date CRL is required for each trusted CA.
9400 There is otherwise no method to distinguish between valid and
9401 invalidated certificates.
9402 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9403 the Internet, so you have to retrieve them by some external mechanism.
9406 \*(UA accepts CRLs in PEM format only;
9407 CRLs in DER format must be converted, like, e.\|g.:
9410 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9413 To tell \*(UA about the CRLs, a directory that contains all CRL files
9414 (and no other files) must be created.
9419 variables, respectively, must then be set to point to that directory.
9420 After that, \*(UA requires a CRL to be present for each CA that is used
9421 to verify a certificate.
9424 .\" .Ss "Handling spam" {{{
9427 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9428 identification of, and, in general, dealing with spam messages.
9429 A precondition of most commands in order to function is that the
9431 variable is set to one of the supported interfaces.
9432 Once messages have been identified as spam their (volatile)
9434 state can be prompted: the
9438 message specifications will address respective messages and their
9440 entries will be used when displaying the
9442 in the header display.
9447 rates the given messages and sets their
9450 If the spam interface offers spam scores those can also be displayed in
9451 the header display by including the
9461 will interact with the Bayesian filter of the chosen interface and learn
9462 the given messages as
9466 respectively; the last command can be used to cause
9468 of messages; it adheres to their current
9470 state and thus reverts previous teachings.
9475 will simply set and clear, respectively, the mentioned volatile
9477 message flag, without any interface interaction.
9484 .Va spam-interface Ns s
9488 require a running instance of the
9490 server in order to function, started with the option
9492 shall Bayesian filter learning be possible.
9494 only works via a local path-based
9496 socket, but otherwise the following will be equivalently fine:
9498 .Bd -literal -offset indent
9499 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9500 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9501 --daemonize [--local] [--allow-tell]
9505 Thereafter \*(UA can make use of these interfaces:
9507 .Bd -literal -offset indent
9508 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9509 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9511 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9512 -Sspamc-command=/usr/local/bin/spamc \e
9513 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9515 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9516 -Sspamc-command=/usr/local/bin/spamc \e
9517 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9521 Using the generic filter approach allows usage of programs like
9525 Here is an example for the former, requiring it to be accessible via
9528 .Bd -literal -offset indent
9529 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
9530 -Sspamfilter-ham="bogofilter -n" \e
9531 -Sspamfilter-noham="bogofilter -N" \e
9532 -Sspamfilter-nospam="bogofilter -S" \e
9533 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9534 -Sspamfilter-spam="bogofilter -s" \e
9535 -Sspamfilter-rate-scanscore="1;^(.+)$"
9539 Because messages must exist on local storage in order to be scored (or
9540 used for Bayesian filter training), it is possibly a good idea to
9541 perform the local spam check last:
9543 .Bd -literal -offset indent
9544 define spamdelhook {
9546 spamset (header x-dcc-brand-metrics "bulk")
9547 # Server-side spamassassin(1)
9548 spamset (header x-spam-flag "YES")
9549 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9555 set folder-hook-FOLDER=spamdelhook
9559 See also the documentation for the variables
9560 .Va spam-interface , spam-maxsize ,
9561 .Va spamc-command , spamc-arguments , spamc-user ,
9562 .Va spamd-socket , spamd-user ,
9563 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9566 .Va spamfilter-rate-scanscore .
9574 .\" .Ss "\*(UA shortly hangs on startup" {{{
9575 .Ss "\*(UA shortly hangs on startup"
9577 This can have two reasons, one is the necessity to wait for a file lock
9578 and can't be helped, the other being that \*(UA calls the function
9580 in order to query the nodename of the box (sometimes the real one is
9581 needed instead of the one represented by the internal variable
9583 You may have varying success by ensuring that the real hostname and
9587 or, more generally, that the name service is properly setup \(en
9590 return what you'd expect?
9591 Does this local hostname has a domain suffix?
9592 RFC 6762 standardized the link-local top-level domain
9596 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9597 .Ss "I can't login to Google mail a.k.a. GMail"
9599 Since 2014 some free service providers classify programs as
9601 unless they use a special authentification method (OAuth 2.0) which
9602 wasn't standardized for non-HTTP protocol authentication token query
9603 until August 2015 (RFC 7628).
9606 Different to Kerberos / GSSAPI, which is developed since the mid of the
9607 1980s, where a user can easily create a local authentication ticket for
9608 her- and himself with the locally installed
9610 program, that protocol has no such local part but instead requires
9611 a world-wide-web query to create or fetch a token; since there is no
9612 local cache this query has to be performed whenever \*(UA is invoked
9613 from the command line (in interactive sessions situation may differ).
9616 \*(UA doesn't support OAuth.
9617 Because of this it is necessary to declare \*(UA a
9619 (on the providers account web page) in order to read and send mail.
9620 However, it also seems possible to take the following steps instead:
9625 give the provider the number of a mobile phone,
9628 .Dq 2-Step Verification ,
9630 create an application specific password (16 characters), and
9632 use that special password instead of your real Google account password in
9633 S-nail (for more on that see the section
9634 .Sx "On URL syntax and credential lookup" ) .
9640 .\" .Sh "SEE ALSO" {{{
9658 .Xr spamassassin 1 ,
9684 M. Douglas McIlroy writes in his article
9685 .Dq A Research UNIX Reader: Annotated Excerpts \
9686 from the Programmer's Manual, 1971-1986
9689 command already appeared in First Edition
9693 .Bd -ragged -offset indent
9694 Electronic mail was there from the start.
9695 Never satisfied with its exact behavior, everybody touched it at one
9696 time or another: to assure the safety of simultaneous access, to improve
9697 privacy, to survive crashes, to exploit uucp, to screen out foreign
9698 freeloaders, or whatever.
9699 Not until v7 did the interface change (Thompson).
9700 Later, as mail became global in its reach, Dave Presotto took charge and
9701 brought order to communications with a grab-bag of external networks
9707 Mail was written in 1978 by Kurt Shoens and developed as part of the
9710 distribution until 1995.
9711 Mail has then seen further development in open source
9713 variants, noticeably by Christos Zoulas in
9715 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9716 Ritter in the years 2000 until 2008.
9717 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9718 This man page is derived from
9719 .Dq The Mail Reference Manual
9720 that was originally written by Kurt Shoens.
9727 .An "Christos Zoulas" ,
9728 .An "Gunnar Ritter" ,
9729 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9731 .Mt s-mailx@sdaoden.eu ) .
9737 The character set conversion uses and relies upon the
9740 Its functionality differs widely between the various system environments
9744 Limitations with POP3 mailboxes are:
9745 It is not possible to edit messages, they can only be copied and deleted.
9746 The line count for the header display is only appropriate if the entire
9747 message has been downloaded from the server.
9748 The status field of a message is maintained by the server between
9749 connections; some servers do not update it at all, and with a server
9752 command will not cause the message status to be reset.
9757 variable have no effect.
9758 It is not possible to rename or to remove POP3 mailboxes.
9765 is typed while a POP3 operation is in progress, \*(UA will wait
9766 until the operation can be safely aborted, and will then return to the
9767 command loop and print the prompt again.
9770 is typed while \*(UA is waiting for the operation to complete, the
9771 operation itself will be cancelled.
9772 In this case, data that has not been fetched yet will have to be fetched
9773 before the next command can be performed.
9774 If the cancelled operation was using an SSL/TLS encrypted channel,
9775 an error in the SSL transport will very likely result and render the
9776 connection unusable.
9779 As \*(UA is a mail user agent, it provides only basic SMTP services.
9780 If it fails to contact its upstream SMTP server, it will not make
9781 further attempts to transfer the message at a later time,
9782 and it does not leave other information about this condition than an
9783 error message on the terminal and an entry in
9785 This is usually not a problem if the SMTP server is located in the same
9786 local network as the computer on which \*(UA is run.
9787 However, care should be taken when using a remote server of an ISP;
9788 it might be better to set up a local SMTP server then which just acts as
9792 \*(UA immediately contacts the SMTP server (or
9794 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9795 servers usually provide much more elaborated delay handling than \*(UA
9796 could perform as a client.
9804 from the distribution or the repository.
9806 After deleting some message of a POP3 mailbox the header summary falsely
9807 claims that there are no messages to display, you need to perform
9808 a scroll or dot movement to restore proper state.
9810 In threaded display a power user may encounter crashes very
9811 occasionally (this is may and very).