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
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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
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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.
496 This can be used to, e.g., automatically format the composed message
497 text before sending the message:
498 .Bd -literal -offset indent
499 $ ( echo 'line one. Word. Word2.'; \e
500 echo '~| /usr/bin/fmt -tuw66' ) |\e
501 LC_ALL=C \*(uA -:/ -d~ bob@exam.ple
507 In batch mode the full set of commands is available, just like in
508 interactive mode, and diverse variable settings and internal states are
509 adjusted for batch necessities, e.g., it sets
520 also no initial header listing will be printed, and processing of
522 is enabled in compose mode.
523 The following prepares an email message in a batched dry run:
524 .Bd -literal -offset indent
525 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en~.\enx\en' | \e
526 LC_ALL=C \*(uA -:/ -d#
531 This flag forces termination of option processing in order to prevent
534 It also forcefully puts \*(UA into send mode, see
535 .Sx "On sending mail, and non-interactive mode" .
539 In the above list of supported command line options,
543 are implemented by means of setting the respective option, as via
546 .Op Ar mta-option ...
548 arguments that are given at the end of the command line after a
550 separator will be passed through to the mail-transfer-agent (MTA) and
551 persist for an entire (interactive) session \(en if the setting of
553 allows their recognition;
554 MTA arguments can also be specified in the variable
555 .Va sendmail-arguments ;
556 find MTA interaction described in more detail in the documentation of
558 MTA arguments are ignored when mail is send via SMTP data transfer.
561 .\" .Ss "A starter" {{{
564 \*(UA is a direct descendant of
566 Mail, a successor of the Research
569 .Dq was there from the start
574 Mail reference manual begins with the following words:
576 .Bd -ragged -offset indent
577 Mail provides a simple and friendly environment for sending and
579 It divides incoming mail into its constituent messages and allows the
580 user to deal with them in any order.
581 In addition, it provides a set of
583 -like commands for manipulating messages and sending mail.
584 Mail offers the user simple editing capabilities to ease the composition
585 of outgoing messages, as well as providing the ability to define and
586 send to names which address groups of users.
590 \*(UA is thus the user side of the
592 mail system, whereas the system side (mail-transfer-agent, MTA) was
593 traditionally taken by
599 are often used for this purpose instead.
600 If the \*(OPal SMTP is included in the
602 of \*(UA then the system side is not a mandatory precondition for mail
606 Because \*(UA strives for compliance with POSIX
608 it is likely that some configuration settings have to be adjusted before
609 using it is a smooth experience.
612 file already bends those standard settings a bit towards more user
613 friendliness and safety, e.g., it sets the
617 variables in order to suppress the automatic moving of messages to
619 that would otherwise occur (see
620 .Sx "Message states" )
623 to not remove empty files in order not to mangle file permissions when
624 files eventually get recreated.
627 option so that by default file grouping (via the
629 prefix as documented also for
634 contains some further suggestions.
637 .\" .Ss "On sending mail, and non-interactive mode" {{{
638 .Ss "On sending mail, and non-interactive mode"
640 To send a message to one or more people, using a local
641 mail-transfer-agent (MTA; the executable path can be set via
643 or the \*(OPal builtin SMTP (set and see the variable
645 transport to actually deliver the generated mail message, \*(UA can be
646 invoked with arguments which are the names of people to whom the mail
649 .Bd -literal -offset indent
650 $ \*(uA -s ubject -a ttach.txt bill@exam.ple 'Bob <bob@exam.ple>'
651 # But... try it in an isolated dry-run mode first
652 $ LC_ALL=C \*(uA -:/ -d -vv -Sfrom="me <he@exam.ple>" \e
653 -b bcc@exam.ple -c cc@exam.ple \e
654 -s Subject -. "(Lovely) Bob <bob@exam.ple>"
658 The command line options
662 can be used to add (blind) carbon copy receivers.
663 Almost always lists of addresses can be given where an address is
665 whereas comma-separated lists should be given, e.g.,
666 .Ql -c """r1@exam.ple , r2@exam.ple,r3@exam.ple""" ,
667 that very example could also be given as the whitespace-separated list
668 .Ql -c """r1@exam.ple r2@exam.ple r3@exam.ple""" ,
669 but which for obvious reasons would not work for
670 .Ql -c """R1 <r1@exam.ple>, R2 (heh!) <r2@exam.ple>""" .
673 The user is then expected to type in the message contents.
674 In this compose mode \*(UA treats lines beginning with the character
676 special \(en these are so-called
678 which can be used to read in files, process shell commands, add and edit
679 attachments and more; e.g., the tilde escape
681 will start the text editor to revise the message in it's current state,
683 allows editing of the message recipients and
685 gives an overview of available tilde escapes.
689 at the beginning of an empty line leaves compose mode and causes the
690 message to be sent, whereas typing
693 twice will abort the current letter (saving its contents in the file
701 A number of variables can be used to alter default behavior; e.g.,
706 will automatically startup a text editor when compose mode is entered,
708 will cause the user to be prompted actively for carbon-copy recipients
711 option will allow leaving compose mode by writing a line consisting
716 Very important, though, is to define which
718 may be used when sending messages, usually by setting the option
721 having read the section
722 .Sx "The mime.types files"
723 to understand how the MIME-type of outgoing attachments is classified
724 and the knowledge that messages are sent asynchronously unless
726 is set: only with it MTA delivery errors will be recognizable.
731 is often necessary (e.g., in conjunction with
733 or desirable, you may want to do some dry-run tests before you go.
734 Saving a copy of the sent messages in a
736 may also be desirable \(en as for most mailbox file targets some
737 special conventions are recognized, see the
739 command for more on that.
741 .Sx "On URL syntax and credential lookup"
742 will spread some light on the
744 variable chains as well as on using URLs for accessing protocol-specific
749 contains an example configuration for sending messages via some of the
750 well-known public mail providers;
751 note it also gives a compact overview on how to setup a secure SSL/TLS
755 Message recipients (as specified on the command line or defined in
760 may not only be email addressees but can also be names of mailboxes and
761 even complete shell command pipe specifications.
762 Proper (shell) quoting is necessary, e.g., to embed whitespace characters.
763 (Recall that \*(UA deals with mail standards, therefore those define the
764 rules with which content is interpreted.)
767 is not set then only network addresses (see
769 for a description of mail addresses) and plain user names (including MTA
770 aliases) may be used, other types will be filtered out, giving a warning
773 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
774 .\" grep the latter for the complete picture
778 is set then extended recipient addresses will optionally be accepted:
779 Any name which starts with a vertical bar
781 character specifies a command pipe \(en the command string following the
783 is executed and the message is sent to its standard input;
784 Likewise, any name that starts with the character slash
786 or the character sequence dot slash
788 is treated as a file, regardless of the remaining content.
789 Any other name which contains an at sign
791 character is treated as a network address;
792 Any other name which starts with a plus sign
794 character specifies a mailbox name;
795 Any other name which contains a slash
797 character but no exclamation mark
801 character before also specifies a mailbox name;
802 What remains is treated as a network address.
804 .Bd -literal -offset indent
805 $ echo bla | \*(uA -Sexpandaddr -s test ./mbox.mbox
806 $ echo bla | \*(uA -Sexpandaddr -s test '|cat >> ./mbox.mbox'
807 $ echo safe | LC_ALL=C \e
808 \*(uA -:/ -Sv15-compat -Ssendwait -Snosave \e
809 -Sexpandaddr=fail,-all,+addr -s test \e
814 It is possible to create personal distribution lists via the
816 command, so that, for instance, the user can send mail to
818 and have it go to a group of people:
821 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
824 Please note that this mechanism has nothing in common with the system
825 wide aliases that may be used by the local MTA (mail-transfer-agent),
826 which are subject to the
830 and are often tracked in a file
836 Personal aliases will be expanded by \*(UA before the message is sent,
837 and are thus a convenient alternative to specifying each addressee by
841 To avoid environmental noise scripts should
843 \*(UA from any configuration files and create a script-local
844 environment, ideally with the command line options
846 to disable any configuration file in conjunction with repititions of
848 to specify variables:
850 .Bd -literal -offset indent
851 $ env LC_ALL=C password=NOTSECRET \e
852 \*(uA -:/ -Sv15-compat -Ssendwait -Snosave \e
853 -Sexpandaddr=fail,-all,+addr \e
854 -S 'smtp=smtps://mylogin@exam.ple:465' -Ssmtp-auth=login \e
855 -S 'from=scriptreply@exam.ple' \e
856 -s 'subject' -a attachment_file \e
857 -. "Recipient 1 <rec1@exam.ple>" rec2@exam.ple \e
862 In interactive mode, which is introduced in the next section, messages
863 can be sent by calling the
865 command with a list of recipient addresses \(em the semantics are
866 completely identical to non-interactive message sending, except that
867 it is likely necessary to separate recipient lists with commas:
869 .Bd -literal -offset indent
870 $ \*(uA -d -Squiet -Semptystart
871 "/var/spool/mail/user": 0 messages
872 ? mail "Recipient 1 <rec1@exam.ple>", rec2@exam.ple
873 ? # Will do the right thing (tm)
874 ? m rec1@exam.ple rec2@exam.ple
878 .\" .Ss "On reading mail, and interactive mode" {{{
879 .Ss "On reading mail, and interactive mode"
881 When invoked without addressees \*(UA enters interactive mode in which
883 When used like that the user's system mailbox (see the command
885 for an in-depth description of the different mailbox types that exist)
886 is read in and a one line header of each message therein is displayed.
887 The visual style of this summary of
889 can be adjusted through the variable
891 and the possible sorting criterion via
893 If the initially opened mailbox is empty \*(UA will instead exit
894 immediately (after displaying a message) unless the variable
903 will give a listing of all available commands and
905 will give a summary of some common ones.
906 If the \*(OPal documentation strings are available one can type
908 and see the actual expansion of
910 and what it's purpose is, i.e., commands can be abbreviated
911 (note that POSIX defines some abbreviations, so that the alphabetical
912 order of commands doesn't necessarily relate to the abbreviations; it is
913 possible to define overwrites with the
918 Messages are given numbers (starting at 1) which uniquely identify
919 messages; the current message \(en the
921 \(en will either be the first new message, or the first unread message,
922 or the first message of the mailbox; the option
924 will instead cause usage of the last message for this purpose.
929 ful of header summaries containing the
933 will display only the summaries of the given messages, defaulting to the
937 Messages can be displayed on the user's terminal with the
941 By default the current message
943 is displayed, but like with many other commands it is possible to give
944 a fancy message specification (see
945 .Sx "Specifying messages" ) ,
948 will display all unread messages,
953 will type the messages 1 and 5,
955 will type the messages 1 through 5, and
959 will display the last and the next message, respectively.
962 (a more substantial alias of the standard command
964 will display a header summary of the given message specification list
965 instead of their content, e.g., the following will search for subjects:
968 .Dl ? from """@Some subject to search for"""
971 In the default setup all header fields of a message will be displayed,
972 but this can be changed: either by blacklisting a list of fields via
974 or by whitelisting only a given list with the
977 .Ql Ic \:retain Ns \0date from to cc subject .
978 In order to display all header fields of a message regardless of
979 currently active ignore or retain lists, use the command
983 controls wether and when \*(UA will use the configured
985 for display instead of directly writing to the user terminal
986 (generally speaking).
987 Note that historically the global
989 not only adjusts the list of displayed headers, but also sets
993 Dependent upon the configuration a line editor (see the section
994 .Sx "On terminal control and line editor" )
995 aims at making user experience with the many
998 When reading the system mailbox or when
1002 specified a mailbox explicitly prefixed with the special
1004 modifier (propagating the mailbox to a primary one) then messages which
1005 have been read will be moved to a secondary mailbox, the user's
1007 file, automatically when the mailbox is left, either by changing the
1008 active mailbox or by quitting \*(UA (also see
1009 .Sx "Message states" )
1010 \(en this automatic moving from a system or primary to the secondary
1011 mailbox is not performed when the variable
1016 After examining a message the user can also
1020 to the sender and all recipients or
1022 exclusively to the sender(s).
1023 Messages can also be
1025 ed (shorter alias is
1027 Note that when replying to or forwarding a message recipient addresses
1028 will be stripped from comments and names unless the option
1031 Deletion causes \*(UA to forget about the message;
1032 This is not irreversible, though, one can
1034 the message by giving its number,
1035 or the \*(UA session can be ended by giving the
1040 To end a mail processing session one may either issue
1042 to cause a full program exit, which possibly includes
1043 automatic moving of read messages to
1045 as well as updating the \*(OPal line editor
1049 instead in order to prevent any of these actions.
1052 .\" .Ss "HTML mail and MIME attachments" {{{
1053 .Ss "HTML mail and MIME attachments"
1055 Messages which are HTML-only get more and more common and of course many
1056 messages come bundled with a bouquet of MIME attachments.
1057 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1058 with HTML messages (see
1059 .Sx "The mime.types files" ) ,
1060 it normally can't deal with any of these itself, but instead programs
1061 need to become registered to deal with specific MIME types or file
1063 These programs may either prepare plain text versions of their input
1064 in order to enable \*(UA to display the content on the terminal,
1065 or display the content themselves, for example in a graphical window.
1068 To install an external handler program for a specific MIME type set an
1070 .Va pipe-TYPE/SUBTYPE
1071 variable; to instead define a handler for a specific file extension set
1074 variable \(en these handlers take precedence.
1075 \*(OPally \*(UA supports mail user agent configuration as defined in
1076 RFC 1524; this mechanism, documented in the section
1077 .Sx "The Mailcap files" ,
1078 will be queried for display or quote handlers if none of the former two
1079 .\" TODO v15-compat "will be" -> "is"
1080 did; it will be the sole source for handlers of other purpose.
1081 A last source for handlers may be the MIME type definition itself, if
1082 the \*(UA specific type-marker extension was used when defining the type
1085 (Many of the builtin MIME types do so by default.)
1089 .Va mime-counter-evidence
1090 can be set to improve dealing with faulty MIME part declarations as are
1091 often seen in real-life messages.
1092 E.g., to display a HTML message inline (that is, converted to a more
1093 fancy plain text representation than the builtin converter is capable to
1094 produce) with either of the text-mode browsers
1098 teach \*(UA about MathML documents and make it display them as plain
1099 text, and to open PDF attachments in an external PDF viewer,
1100 asynchronously and with some other magic attached:
1102 .Bd -literal -offset indent
1103 if $features !@ HTML-FILTER
1104 #set pipe-text/html="elinks -force-html -dump 1"
1105 set pipe-text/html="lynx -stdin -dump -force_html"
1106 # Display HTML as plain text instead
1107 #set pipe-text/html=@
1109 mimetype '@ application/mathml+xml mathml'
1110 set pipe-application/pdf="@&=@ \e
1111 trap \e"rm -f \e\e\e"${NAIL_FILENAME_TEMPORARY}\e\e\e"\e" EXIT;\e
1112 trap \e"trap \e\e\e"\e\e\e" INT QUIT TERM; exit 1\e" \e INT QUIT TERM;\e
1113 xpdf \e"${NAIL_FILENAME_TEMPORARY}\e""
1117 Note: special care must be taken when using such commands as mail
1118 viruses may be distributed by this method: if messages of type
1119 .Ql application/x-sh
1120 or files with the extension
1122 were blindly filtered through the shell, for example, a message sender
1123 could easily execute arbitrary code on the system \*(UA is running on.
1124 For more on MIME, also in respect to sending of messages, see the
1126 .Sx "The mime.types files" ,
1127 .Sx "The Mailcap files"
1132 .\" .Ss "Mailing lists" {{{
1135 \*(UA offers some support to ease handling of mailing lists.
1138 promotes all given arguments to known mailing lists, and
1140 sets their subscription attribute, creating them first as necessary.
1145 automatically, but only resets the subscription attribute.)
1146 Using the commands without arguments will show (a subset of) all
1147 currently defined mailing lists.
1152 can be used to mark out messages with configured list addresses
1153 in the header display.
1156 \*(OPally mailing lists may also be specified as (extended) regular
1157 expressions, which allows matching of many addresses with a single
1159 However, all fully qualified list addresses are matched via a fast
1160 dictionary, whereas expressions are placed in (a) list(s) which is
1161 (are) matched sequentially.
1163 .Bd -literal -offset indent
1164 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1165 mlist a1@b1\e.c1 a2@b2\e.c2 .*@lists\e.c3$
1166 mlsubscribe a4@b4\e.c4 exact@lists\e.c3
1171 .Va followup-to-honour
1173 .Ql Mail-\:Followup-\:To:
1174 header is honoured when the message is being replied to (via
1180 controls wether this header is created when sending mails; it will be
1181 created automatically for a couple of reasons, too, like when the
1183 .Dq mailing list specific
1188 is used to respond to a message with its
1189 .Ql Mail-Followup-To:
1193 A difference in between the handling of known and subscribed lists is
1194 that the address of the sender is usually not part of a generated
1195 .Ql Mail-Followup-To:
1196 when addressing the latter, whereas it is for the former kind of lists.
1197 Usually because there are exceptions: say, if multiple lists are
1198 addressed and not all of them are subscribed lists.
1200 For convenience \*(UA will, temporarily, automatically add a list
1201 address that is presented in the
1203 header of a message that is being responded to to the list of known
1205 Shall that header have existed \*(UA will instead, dependend on the
1207 .Va reply-to-honour ,
1210 for this purpose in order to accept a list administrators' wish that
1211 is supposed to have been manifested like that (but only if it provides
1212 a single address which resides on the same domain as what is stated in
1216 .\" .Ss "Resource files" {{{
1217 .Ss "Resource files"
1219 Upon startup \*(UA reads in several resource files:
1221 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1224 System wide initialization file.
1225 Reading of this file can be suppressed, either by using the
1229 command line options, or by setting the environment variable
1230 .Ev NAIL_NO_SYSTEM_RC .
1234 File giving initial commands.
1235 A different file can be chosen by setting the environment variable
1237 Reading of this file can be suppressed with the
1239 command line option.
1241 .It Va NAIL_EXTRA_RC
1242 Can be used to define an optional startup file to be read after all
1243 other resource files.
1244 It can be used to specify settings that are not understood by other
1246 implementations, for example.
1247 This variable is only honoured when defined in a resource file.
1251 The content of these files is interpreted as follows:
1254 .Bl -bullet -compact
1256 A lines' leading whitespace is removed.
1258 Empty lines are ignored.
1260 Any other line is interpreted as a command.
1261 It may be spread over multiple input lines if the newline character is
1263 by placing a backslash character
1265 as the last character of the line; whereas any leading whitespace of
1266 follow lines is ignored, trailing whitespace before a escaped newline
1267 remains in the input.
1269 If the line (content) starts with the number sign
1271 then it is a comment-command \(en a real command! \(en and also ignored.
1272 This command is the only form of comment that is understood.
1276 Unless \*(UA is about to enter interactive mode syntax errors that occur
1277 while loading these files are treated as errors and cause program exit.
1278 More files with syntactically equal content can be
1280 The following, saved in a file, would be an examplary content:
1282 .Bd -literal -offset indent
1283 # This line is a comment command. And y\e
1284 es, it is really continued here.
1291 .\" .Ss "Character sets" {{{
1292 .Ss "Character sets"
1294 \*(OP \*(UA detects the character set of the terminal by using
1295 mechanisms that are controlled by the
1300 should give an overview); the \*(UA internal variable
1302 will be set to the detected terminal character set accordingly
1303 and will thus show up in the output of the commands
1309 However, a user supplied
1311 value is not overwritten by this detection mechanism: this
1313 must be used if the detection doesn't work properly,
1314 and it may be used to adjust the name of the locale character set.
1315 E.g., on BSD systems one may use a locale with the character set
1316 ISO8859-1, which is not a valid name for this character set; to be on
1317 the safe side, one may set
1319 to the correct name, which is ISO-8859-1.
1322 Note that changing the value doesn't mean much beside that,
1323 since several aspects of the real character set are implied by the
1324 locale environment of the system,
1325 and that stays unaffected by the content of an overwritten
1328 (This is mostly an issue when interactively using \*(UA, though.
1329 It is actually possible to send mail in a completely
1331 locale environment, an option that \*(UA's test-suite uses excessively.)
1334 If no character set conversion capabilities have been compiled into
1337 doesn't include the term
1341 will be the only supported character set,
1342 it is simply assumed that it can be used to exchange 8-bit messages,
1343 and the rest of this section does not apply;
1344 it may however still be necessary to explicitly set it if automatic
1345 detection fails, since in that case it defaults to the mentioned
1346 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1350 When reading messages, their text is converted into
1352 as necessary in order to display them on the users terminal.
1353 Unprintable characters and invalid byte sequences are detected
1354 and replaced by proper substitution characters (unless the variable
1356 was set once \*(UA was started).
1358 .Va charset-unknown-8bit
1359 to deal with another hairy aspect of message interpretation.
1362 When sending messages all their parts and attachments are classified.
1363 Whereas no character set conversion is performed on those parts which
1364 appear to be binary data,
1365 the character set being used must be declared within the MIME header of
1366 an outgoing text part if it contains characters that do not conform to
1367 the set of characters that are allowed by the email standards.
1368 Permissible values for character sets can be declared using the
1372 which defines a catch-all last-resort fallback character set that is
1373 implicitly appended to the list of character-sets in
1377 When replying to a message and the variable
1378 .Va reply-in-same-charset
1379 is set then the character set of the message being replied to is tried
1381 And it is also possible to make \*(UA work even more closely related to
1382 the current locale setting automatically by using the variable
1383 .Va sendcharsets-else-ttycharset ,
1384 please see there for more information.
1387 All the specified character sets are tried in order unless the
1388 conversion of the part or attachment succeeds.
1389 If none of the tried (8-bit) character sets is capable to represent the
1390 content of the part or attachment,
1391 then the message will not be sent and its text will optionally be
1395 In general, if the message
1396 .Dq Cannot convert from a to b
1397 appears, either some characters are not appropriate for the currently
1398 selected (terminal) character set,
1399 or the needed conversion is not supported by the system.
1400 In the first case, it is necessary to set an appropriate
1402 locale and/or the variable
1406 The best results are usually achieved when \*(UA is run in a UTF-8
1407 locale on a UTF-8 capable terminal, in which case the full Unicode
1408 spectrum of characters is available.
1409 In this setup characters from various countries can be displayed,
1410 while it is still possible to use more simple character sets for sending
1411 to retain maximum compatibility with older mail clients.
1414 On the other hand the POSIX standard defines a locale-independent 7-bit
1415 .Dq portable character set
1416 that should be used when overall portability is an issue, the even more
1417 restricted subset named
1418 .Dq portable filename character set
1419 consisting of A-Z, a-z, 0-9, period
1428 .\" .Ss "Message states" {{{
1429 .Ss "Message states"
1431 \*(UA differentiates in between several different message states;
1432 the current state will be reflected in header summary displays if
1434 is configured to do so (via the internal variable
1436 and messages can also be selected and be acted upon depending on their
1438 .Sx "Specifying messages" ) .
1439 When operating on the system mailbox or in primary mailboxes opened with
1444 special actions, like the automatic moving of messages to the secondary
1446 mailbox may be applied when the mailbox is left (also implicitly via
1447 a successful exit of \*(UA, but not if the special command
1449 is used) \(en however, because this may be irritating to users which
1452 mail-user-agents, the default global
1458 variables in order to suppress this behaviour.
1460 .Bl -tag -width ".It Ql _reserved"
1462 Message has neither been viewed nor moved to any other state.
1463 Such messages are retained even in the system mailbox.
1466 Message has neither been viewed nor moved to any other state, but the
1467 message was present already when the mailbox has been opened last:
1468 Such messages are retained even in the system mailbox.
1471 The message has been processed by one of the following commands:
1491 commands may also cause the next message to be marked as read, depending
1497 command is used, messages that are in the system mailbox or in mailboxes
1498 which were opened with the special
1502 state when the mailbox is left will be saved in
1509 The message has been processed by one of the following commands:
1515 can be used to access such messages.
1518 The message has been processed by a
1520 command and it will be retained in its current location.
1523 The message has been processed by one of the following commands:
1529 command is used, messages that are in the system mailbox or in mailboxes
1530 which were opened with the special
1534 state when the mailbox is left will be deleted; they will be saved in
1542 .\" .Ss "Specifying messages" {{{
1543 .Ss "Specifying messages"
1550 can be given a list of message numbers as arguments to apply to a number
1551 of messages at once.
1554 deletes messages 1 and 2,
1557 will delete the messages 1 through 5.
1558 In sorted or threaded mode (see the
1562 will delete the messages that are located between (and including)
1563 messages 1 through 5 in the sorted/threaded order, as shown in the
1566 Multiple colon modifiers can be joined into one, e.g.,
1568 The following special message names exist:
1570 .Bl -tag -width ".It Ar _n_u"
1576 All old messages (any not in state
1601 All answered messages
1606 All messages marked as draft.
1608 \*(OP All messages classified as spam.
1610 \*(OP All messages with unsure spam classification.
1612 The current message, the so-called
1615 The message that was previously the current message.
1617 The parent message of the current message,
1618 that is the message with the Message-ID given in the
1620 field or the last entry of the
1622 field of the current message.
1624 The next previous undeleted message,
1625 or the next previous deleted message for the
1628 In sorted/threaded mode,
1629 the next previous such message in the sorted/threaded order.
1631 The next undeleted message,
1632 or the next deleted message for the
1635 In sorted/threaded mode,
1636 the next such message in the sorted/threaded order.
1638 The first undeleted message,
1639 or the first deleted message for the
1642 In sorted/threaded mode,
1643 the first such message in the sorted/threaded order.
1646 In sorted/threaded mode,
1647 the last message in the sorted/threaded order.
1651 selects the message addressed with
1655 is any other message specification,
1656 and all messages from the thread that begins at it.
1657 Otherwise it is identical to
1662 the thread beginning with the current message is selected.
1667 All messages that were included in the message list for the previous
1670 .It Ar / Ns Ar string
1671 All messages that contain
1673 in the subject field (case ignored).
1680 the string from the previous specification of that type is used again.
1682 .It Xo Op Ar @ Ns Ar name-list Ns
1685 All messages that contain the given case-insensitive search
1687 ession; if the \*(OPal regular expression (see
1689 support is available
1691 will be interpreted as (an extended) one if any of the
1693 (extended) regular expression characters is seen.
1695 .Ar @ Ns Ar name-list
1696 part is missing, the search is restricted to the subject field body,
1699 specifies a comma-separated list of header fields to search, as in
1701 .Dl '@to,from,cc@Someone i ought to know'
1703 In order to search for a string that includes a
1705 (commercial at) character the
1707 is effectively non-optional, but may be given as the empty string.
1708 Some special header fields may be abbreviated:
1722 respectively and case-insensitively.
1727 can be used to search in (all of) the header(s) of the message, and the
1736 can be used to perform full text searches \(en whereas the former
1737 searches only the body, the latter also searches the message header.
1739 This message specification performs full text comparison, but even with
1740 regular expression support it is almost impossible to write a search
1741 expression that savely matches only a specific address domain.
1742 To request that the content of the header is treated as a list of
1743 addresses, and to strip those down to the plain email address which the
1744 search expression is to be matched against, prefix the header name
1745 (abbreviation) with a tilde
1748 .Dl @~f@@a\e.safe\e.domain\e.match$
1752 .Dq any substring matches
1755 header, which will match addresses (too) even if
1757 is set (and POSIX says
1758 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1761 variable is set, only the local part of the address is evaluated
1762 for the comparison, not ignoring case, and the setting of
1764 is completely ignored.
1765 For finer control and match boundaries use the
1767 search expression; the \*(OPal IMAP-style
1769 expression can also be used if substring matches are desired.
1773 \*(OP IMAP-style SEARCH expressions may also be used.
1774 This addressing mode is available with all types of folders;
1775 \*(UA will perform the search locally as necessary.
1776 Strings must be enclosed by double quotes
1778 in their entirety if they contain white space or parentheses;
1779 within the quotes, only backslash
1781 is recognized as an escape character.
1782 All string searches are case-insensitive.
1783 When the description indicates that the
1785 representation of an address field is used,
1786 this means that the search string is checked against both a list
1789 .Bd -literal -offset indent
1790 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1795 and the addresses without real names from the respective header field.
1796 These search expressions can be nested using parentheses, see below for
1800 .Bl -tag -compact -width ".It Ar _n_u"
1801 .It Ar ( criterion )
1802 All messages that satisfy the given
1804 .It Ar ( criterion1 criterion2 ... criterionN )
1805 All messages that satisfy all of the given criteria.
1807 .It Ar ( or criterion1 criterion2 )
1808 All messages that satisfy either
1813 To connect more than two criteria using
1815 specifications have to be nested using additional parentheses,
1817 .Ql (or a (or b c)) ,
1821 .Ql ((a or b) and c) .
1824 operation of independent criteria on the lowest nesting level,
1825 it is possible to achieve similar effects by using three separate
1829 .It Ar ( not criterion )
1830 All messages that do not satisfy
1832 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1833 All messages that contain
1835 in the envelope representation of the
1838 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1839 All messages that contain
1841 in the envelope representation of the
1844 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1845 All messages that contain
1847 in the envelope representation of the
1850 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1851 All messages that contain
1856 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1857 All messages that contain
1859 in the envelope representation of the
1862 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1863 All messages that contain
1868 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1869 All messages that contain
1872 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1873 All messages that contain
1875 in their header or body.
1876 .It Ar ( larger size )
1877 All messages that are larger than
1880 .It Ar ( smaller size )
1881 All messages that are smaller than
1885 .It Ar ( before date )
1886 All messages that were received before
1888 which must be in the form
1892 denotes the day of the month as one or two digits,
1894 is the name of the month \(en one of
1895 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1898 is the year as four digits, e.g.,
1902 All messages that were received on the specified date.
1903 .It Ar ( since date )
1904 All messages that were received since the specified date.
1905 .It Ar ( sentbefore date )
1906 All messages that were sent on the specified date.
1907 .It Ar ( senton date )
1908 All messages that were sent on the specified date.
1909 .It Ar ( sentsince date )
1910 All messages that were sent since the specified date.
1912 The same criterion as for the previous search.
1913 This specification cannot be used as part of another criterion.
1914 If the previous command line contained more than one independent
1915 criterion then the last of those criteria is used.
1919 .\" .Ss "On URL syntax and credential lookup" {{{
1920 .Ss "On URL syntax and credential lookup"
1922 \*(IN For accessing protocol-specific resources usage of Uniform
1923 Resource Locators (URL, RFC 1738) has become omnipresent.
1924 \*(UA expects and understands URLs in the following form;
1927 denote optional parts, optional either because there also exist other
1928 ways to define the information in question or because support of the
1929 part is protocol-specific (e.g.,
1931 is used by the IMAP protocol but not by POP3);
1936 are specified they must be given in URL percent encoded form (RFC 3986;
1944 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1947 Note that these \*(UA URLs most often don't conform to any real
1948 standard, but instead represent a normalized variant of RFC 1738 \(en
1949 they are not used in data exchange but only ment as a compact,
1950 easy-to-use way of defining and representing information in
1951 a well-known notation.
1954 Many internal variables of \*(UA exist in multiple versions, called
1955 variable chains for the rest of this document: the plain
1960 .Ql variable-USER@HOST .
1967 had been specified in the respective URL, otherwise it refers to the plain
1973 that had been found when doing the user chain lookup as is described
1976 will never be in URL percent encoded form, wether it came from an URL or
1977 not; i.e., values of
1978 .Sx "INTERNAL VARIABLES"
1979 must not be URL percent encoded.
1982 For example, wether an hypothetical URL
1983 .Ql smtp://hey%3Ayou@our.house
1984 had been given that includes a user, or wether the URL was
1985 .Ql smtp://our.house
1986 and the user had been found differently, to lookup the variable chain
1987 .Va smtp-use-starttls
1988 \*(UA first looks for wether
1989 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1990 is defined, then wether
1991 .Ql smtp-\:use-\:starttls-\:our.house
1992 exists before finally ending up looking at the plain variable itself.
1995 \*(UA obeys the following logic scheme when dealing with the
1996 necessary credential informations of an account:
2002 has been given in the URL the variables
2006 are looked up; if no such variable(s) can be found then \*(UA will,
2007 when enforced by the \*(OPal variables
2008 .Va netrc-lookup-HOST
2015 specific entry which provides a
2017 name: this lookup will only succeed if unambiguous (one possible matching
2021 If there is still no
2023 then \*(UA will fall back to the user who is supposed to run \*(UA:
2024 either the name that has been given with the
2026 command line option (or, equivalently, but with less precedence, the
2027 environment variable
2032 The identity of this user has been fixated during \*(UA startup and is
2033 known to be a valid user on the current host.
2036 Authentication: unless otherwise noted this will lookup the
2037 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
2038 variable chain, falling back to a protocol-specific default should this
2044 has been given in the URL, then if the
2046 has been found through the \*(OPal
2048 then that may have already provided the password, too.
2049 Otherwise the variable chain
2050 .Va password-USER@HOST , password-HOST , password
2051 is looked up and used if existent.
2053 \*(OP Then if any of the variables of the chain
2054 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2056 is set the shell command specified therein is run and the output (less
2057 newline characters) will be used as the password.
2058 It is perfectly valid for such an agent to simply not return any data,
2059 in which case the password lookup is continued somewhere else;
2060 Any command failure is treated as a hard error, however.
2062 Afterwards the complete \*(OPal variable chain
2063 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2067 cache is searched for a password only (multiple user accounts for
2068 a single machine may exist as well as a fallback entry without user
2069 but with a password).
2071 If at that point there is still no password available, but the
2072 (protocols') chosen authentication type requires a password, then in
2073 interactive mode the user will be prompted on the terminal.
2078 S/MIME verification works relative to the values found in the
2082 header field(s), which means that the values of
2083 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2085 .Va smime-sign-message-digest
2086 will not be looked up using the
2090 chains from above but instead use the corresponding values from the
2091 message that is being worked on.
2092 In unusual cases multiple and different
2096 combinations may therefore be involved \(en on the other hand those
2097 unusual cases become possible.
2098 The usual case is as short as:
2101 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2102 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2107 contains complete example configurations.
2110 .\" .Ss "On terminal control and line editor" {{{
2111 .Ss "On terminal control and line editor"
2113 \*(OP \*(UA can be configured to support a line editor,
2114 history lists that can be saved in between sessions,
2115 and terminal control to improve interactive usage experience.
2116 For the former one may either link against an external library
2117 .Pf ( Xr readline 3 ;
2118 behaviour of \*(UA may differ slightly),
2119 or enable the builtin Mailx-Line-Editor (MLE), which should work in all
2120 environments which comply to the ISO C standard
2122 and which will support wide glyphs if possible (the necessary
2123 functionality had been removed from ISO C, but was included in
2125 Prevent usage of a line editor in interactive mode by setting the
2127 .Va line-editor-disable .
2132 feature is available then input from line editor prompts will be saved
2133 in a history list that can be searched in and be expanded from.
2134 Such saving can be prevented by prefixing input with any amount of
2136 Aspects of history, like allowed content, maximum size etc., can be
2137 configured with the variables
2140 .Va history-gabby-persist
2145 \*(OP Terminal control will be realized through one of the standard
2147 libraries, either the
2149 or, alternatively, the
2151 both of which will be initialized to work with the environment variable
2153 Terminal control will enhance or enable interactive usage aspects, e.g.,
2154 .Sx "Coloured display" ,
2155 and extend behaviour of the MLE, which may learn the key-sequences of
2156 keys like the cursor and function keys, and which will automatically
2159 alternative screen shall the terminal support it.
2160 The internal variable
2162 can be used to overwrite settings or to learn (correct(ed)) keycodes.
2163 Actual interaction with the chosen library can be disabled completely by
2164 setting the internal variable
2165 .Va termcap-disable ,
2166 which may be necessary for proper operation on the actual terminal;
2168 will be queried regardless, even if the \*(OPal support for the
2169 libraries has not been enabled at configuration time.
2172 \*(OP The builtin \*(UA line editor MLE supports the following
2173 operations; the notation
2175 stands for the combination of the
2177 key plus the mentioned character, e.g.,
2180 .Dq hold down control key and press the A key .
2181 Especially without termcap support setting respective entries in
2183 will help shall the MLE misbehave.
2184 The MLE also supports several
2189 .Bl -tag -compact -width "Ql _M"
2191 Go to the start of the line.
2193 Move the cursor backward one character.
2195 Forward delete the character under the cursor;
2196 quits \*(UA if used on the empty line unless the
2200 Go to the end of the line.
2202 Move the cursor forward one character.
2205 Cancel current operation, full reset.
2206 If there is an active history search or tabulator expansion then this
2207 command will first reset that, reverting to the former line content;
2208 thus a second reset is needed for a full reset in this case.
2209 In all cases \*(UA will reset a possibly used multibyte character input
2215 backward delete one character.
2219 .Dq horizontal tabulator :
2220 try to expand the word before the cursor.
2222 .Dq tabulator-completion
2223 as is known from the
2225 but really means the usual \*(UA expansion, as documented for
2227 yet it involves shell expansion as a last step, too.)
2232 complete this line of input.
2234 Delete all characters from the cursor to the end of the line.
2238 \*(OP Go to the next history entry.
2243 \*(OP Go to the previous history entry.
2245 \*(OP Complete the current line from (the remaining older) history entries.
2252 Prompts for a Unicode character to be inserted.
2254 Delete the characters from the one preceding the cursor to the preceding
2257 Move the cursor forward one word boundary.
2259 Move the cursor backward one word boundary.
2263 If the keycodes are known then the left and right cursor keys will map to
2267 respectively, the up and down cursor keys will map to
2271 and the Home/End/PgUp/PgDown keys will call the
2273 command with the respective arguments
2279 (i.e., perform scrolling through the header summary list).
2280 Also the up and down cursor keys should invoke
2282 for up- and downwards movement if they are used while the
2287 .\" .Ss "Coloured display" {{{
2288 .Ss "Coloured display"
2290 \*(OP \*(UA can be configured to support a coloured display and font
2291 attributes by emitting ANSI / ISO 6429 SGR (select graphic rendition)
2293 Usage of colours and font attributes solely depends upon the
2294 capability of the detected terminal type that is defined by the
2295 environment variable
2297 and which can be fine-tuned by the user via the internal variable
2301 On top of what \*(UA knows about the terminal the boolean variable
2303 defines wether the actually applicable colour and font attribute
2304 sequences should also be generated when output is going to be paged
2305 through the external program defined by the environment variable
2310 This is not enabled by default because different pager programs need
2311 different command line switches or other configuration in order to
2312 support those sequences.
2313 \*(UA however knows about some widely used pagers and in a clean
2314 environment it is often enough to simply set
2316 please refer to that variable for more on this topic.
2321 is set then any active usage of colour and font attribute sequences
2322 is suppressed, but without affecting possibly established
2327 To define and control colours and font attributes a single multiplexer
2328 command family exists:
2330 shows or defines colour mappings for the given colour type (e.g.,
2333 can be used to remove mappings of a given colour type.
2334 Since colours are only available in interactive mode, it may make
2335 sense to conditionalize the colour setup by encapsulating it with
2338 .Bd -literal -offset indent
2339 if terminal && $features =@ +colour
2340 colour iso view-msginfo ft=bold,fg=green
2341 colour iso view-header ft=bold,fg=red "from,subject"
2342 colour iso view-header fg=red
2344 uncolour iso view-header from,subject
2345 colour iso view-header ft=bold,fg=magenta,bg=cyan
2346 colour 256 view-header ft=bold,fg=208,bg=230 subject,from
2347 colour mono view-header ft=bold
2348 colour mono view-header ft=bold,ft=reverse subject,from
2352 .\" }}} (DESCRIPTION)
2355 .\" .Sh COMMANDS {{{
2358 Each command is typed on a line by itself,
2359 and may take arguments following the command word.
2360 The command need not be typed in its entirety \(en
2361 the first command which matches the typed prefix is used.
2362 An \(en alphabetically \(en sorted list of commands can be shown
2369 when given an argument, will show a documentation string for the
2370 command matching the expanded argument, as in
2372 which should be a shorthand of
2374 documentation strings are however \*(OPal.
2377 For commands which take message lists as arguments, the next message
2378 forward that satisfies the command's requirements will be used shall no
2379 explicit message list have been specified.
2380 If there are no messages forward of the current message,
2381 the search proceeds backwards,
2382 and if there are no good messages at all,
2384 .Dq no applicable messages
2385 and aborts the command.
2386 The arguments to commands can be quoted, using the following methods:
2389 .Bl -bullet -compact -offset indent
2391 An argument can be enclosed between paired double-quotes
2396 any white space, shell word expansion, or backslash characters (except
2397 as described next) within the quotes are treated literally as part of
2399 A double-quote will be treated literally within single-quotes and vice
2401 Inside such a quoted string the actually used quote character can be
2402 used nonetheless by escaping it with a backslash
2408 An argument that is not enclosed in quotes, as above, can usually still
2409 contain space characters if those spaces are backslash-escaped, as in
2413 A backslash outside of the enclosing quotes is discarded
2414 and the following character is treated literally as part of the argument.
2417 An unquoted backslash at the end of a command line is discarded and the
2418 next line continues the command.
2422 Filenames, where expected, are subsequently subjected to the following
2423 transformations, in sequence:
2426 .Bl -bullet -compact -offset indent
2428 If the filename begins with an unquoted plus sign, and the
2430 variable is defined,
2431 the plus sign will be replaced by the value of the
2433 variable followed by a slash.
2436 variable is unset or is set to null, the filename will be unchanged.
2439 Shell word expansions are applied to the filename.
2440 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2441 .Sy Compatibility note:
2442 on the long run support for complete shell word expansion will be
2443 replaced by an internally implemented restricted expansion mechanism in
2444 order to circumvent possible security impacts through shell expansion.
2445 Expect that a growing number of program parts only support this
2448 Meta expansions are applied to the filename: leading tilde characters
2450 will be replaced by the expansion of
2452 and any occurrence of
2456 will be replaced by the expansion of the variable, if possible;
2457 \*(UA internal as well as environmental (shell) variables can be
2458 accessed through this mechanism.
2459 In order to include a raw
2461 character precede it with a backslash
2463 to include a backslash double it.
2464 If more than a single pathname results from this expansion and the
2465 command is expecting one file, an error results.
2467 Note that in interactive display context, in order to allow simple
2468 value acceptance (typing
2470 backslash quoting is performed automatically as necessary, e.g., a file
2471 .Ql diet\e is \ecurd.txt
2472 will be displayed as
2473 .Ql diet\e\e is \e\ecurd.txt .
2477 The following commands are available:
2479 .Bl -tag -width ".Ic _ccount"
2486 ) command which follows.
2490 The comment-command causes the entire line to be ignored.
2492 this really is a normal command which' purpose is to discard its
2495 indicating special character, which means that, e.g., trailing comments
2496 on a line are not possible.
2500 Goes to the next message in sequence and types it
2506 Display the preceding message, or the n'th previous message if given
2507 a numeric argument n.
2511 Show the current message number (the
2516 Show a brief summary of commands.
2517 \*(OP Given an argument a synopsis for the command in question is
2518 shown instead; commands can be abbreviated in general and this command
2519 can be used to see the full expansion of an abbreviation including the
2520 synopsis, try, e.g.,
2525 and see how the output changes.
2535 Interprets the remainder of the word as a macro name and passes it
2540 is a shorter synonym for
2541 .Ql call Ar mymacro .
2545 (ac) Creates, selects or lists (an) account(s).
2546 An account is a group of commands and variable settings which together
2547 usually arrange the environment for the purpose of creating a system login.
2548 Without any argument a listing of all defined accounts and their content
2550 A specific account can be activated by giving solely its name, resulting
2551 in the system mailbox or inbox of that account to be activated as via an
2552 explicit use of the command
2554 The two argument form is identical to defining a macro as via
2557 .Bd -literal -offset indent
2561 set from="myname@myisp.example (My Name)"
2562 set smtp=smtp://mylogin@smtp.myisp.example
2566 creates an account named
2568 which can later be selected by specifying
2572 (case-insensitive) always exists.
2574 are enabled by default and localize account settings \(en different to
2575 normal macros the settings will be reverted once the account is switched off.
2576 Accounts can be deleted via
2581 (a) With no arguments, shows all currently-defined aliases.
2582 With one argument, shows that alias.
2583 With more than one argument,
2584 creates a new alias or appends to an existing one.
2586 can be used to delete aliases.
2590 (alt) Manage a list of alternate addresses / names of the active user,
2591 members of which will be removed from recipient lists when replying to
2594 variable is not set).
2595 If arguments are given the set of alternate names is replaced by them,
2596 without arguments the current set is displayed.
2600 Takes a message list and marks each message as having been answered.
2601 This mark has no technical meaning in the mail system;
2602 it just causes messages to be marked in the header summary,
2603 and makes them specially addressable.
2607 Calls a macro that has been created via
2612 (ch) Change the working directory to
2614 or the given argument.
2620 \*(OP Only applicable to S/MIME signed messages.
2621 Takes a message list and a file name and saves the certificates
2622 contained within the message signatures to the named file in both
2623 human-readable and PEM format.
2624 The certificates can later be used to send encrypted messages to the
2625 respective message senders by setting
2626 .Va smime-encrypt-USER@HOST
2631 (ch) Change the working directory to
2633 or the given argument.
2639 Only applicable to threaded mode.
2640 Takes a message list and makes all replies to these messages invisible
2641 in header summaries, unless they are in state
2647 \*(OP Manage colour mappings for the type of colour given as the
2648 (case-insensitive) first argument, which must be one of
2650 for 256-colour terminals,
2655 for the standard 8-colour ANSI / ISO 6429 color palette and
2659 for monochrome terminals.
2660 Monochrome terminals cannot deal with colours, but only (some) font
2664 Without further arguments the list of all currently defined mappings
2665 for the given colour type is shown (as a special case giving
2669 will iterate over all types in order).
2670 Otherwise the second argument defines the mappable slot, the third
2671 argument a (comma-separated list of) colour and font attribute
2672 specification(s), and the optional fourth argument can be used to
2673 specify a precondition: if conditioned mappings exist they are tested in
2674 (creation) order unless a (case-insensitive) match has been found, and
2675 the default mapping (if any has been established) will only be chosen as
2677 The types of precondition available depend on the mappable slot, the
2678 following of which exist:
2681 Mappings prefixed with
2683 are used for the \*(OPal builtin Mailx-Line-Editor (MLE, see
2684 .Sx "On terminal control and line editor" )
2685 and don't support preconditions.
2687 .Bl -tag -compact -width view-partinfo
2689 This mapping is used for the position indicator that is visible when
2690 a line cannot be fully displayed on the screen.
2697 Mappings prefixed with
2699 are used in header summaries, and they all understand the preconditions
2701 (the current message) and
2703 for elder messages (only honoured in conjunction with
2704 .Va datefield-markout-older ) .
2706 .Bl -tag -compact -width view-partinfo
2708 This mapping is used for the
2710 that can be created with the
2714 formats of the variable
2717 For the complete header summary line except the
2719 and the thread structure.
2721 For the thread structure which can be created with the
2723 format of the variable
2728 Mappings prefixed with
2730 are used when displaying messages.
2732 .Bl -tag -compact -width view-partinfo
2734 This mapping is used for so-called
2736 lines, which are MBOX file format specific header lines.
2739 A comma-separated list of headers to which the mapping applies may be
2740 given as a precondition; if the \*(OPal regular expression support is
2741 available then if any of the
2743 (extended) regular expression characters is seen the precondition will
2744 be evaluated as (an extended) one.
2746 For the introductional message info line.
2747 .It Cd view-partinfo
2748 For MIME part info lines.
2752 The following (case-insensitive) colour definitions and font attributes
2753 are understood, multiple of which can be specified in a comma-separated
2763 It is possible (and often applicable) to specify multiple font
2764 attributes for a single mapping.
2767 foreground colour attribute:
2777 To specify a 256-color mode a decimal number colour specification in
2778 the range 0 to 255, inclusive, is supported, and interpreted as follows:
2780 .Bl -tag -compact -width "999 - 999"
2782 the standard ISO 6429 colors, as above.
2784 high intensity variants of the standard colors.
2786 216 colors in tuples of 6.
2788 grayscale from black to white in 24 steps.
2790 .Bd -literal -offset indent
2792 fg() { printf "\e033[38;5;${1}m($1)"; }
2793 bg() { printf "\e033[48;5;${1}m($1)"; }
2795 while [ $i -lt 256 ]; do fg $i; i=$(($i + 1)); done
2796 printf "\e033[0m\en"
2798 while [ $i -lt 256 ]; do bg $i; i=$(($i + 1)); done
2799 printf "\e033[0m\en"
2803 background colour attribute (see
2805 for possible values).
2809 Mappings may be removed with the command
2811 For a generic overview see the section
2812 .Sx "Coloured display" .
2817 (C) Copy messages to files whose names are derived from the author of
2818 the respective message and don't mark them as being saved;
2819 otherwise identical to
2824 (c) Copy messages to the named file and don't mark them as being saved;
2825 otherwise identical to
2830 With no arguments, shows all currently-defined custom headers.
2831 With one argument, shows that custom header.
2832 With more than one argument, creates a new or replaces an existing
2833 custom header with the name given as the first argument, the content of
2834 which being defined by the concatenated remaining arguments.
2836 can be used to delete custom headers.
2837 \*(ID Overwriting of automatically managed headers is neither supported
2839 Defined custom headers will be injected into newly composed or forwarded
2842 .Dl customhdr OpenPGP id=12345678; url=http://www.YYY.ZZ
2846 may also be used to inject custom headers; it is covered by
2851 Show the name of the current working directory.
2855 \*(OP For unencrypted messages this command is identical to
2857 Encrypted messages are first decrypted, if possible, and then copied.
2861 \*(OP For unencrypted messages this command is identical to
2863 Encrypted messages are first decrypted, if possible, and then copied.
2867 Without arguments the current list of macros, including their content,
2868 is shown, otherwise a macro is defined.
2869 A macro definition is a sequence of commands in the following form:
2870 .Bd -literal -offset indent
2879 A defined macro can be invoked explicitly by using the
2883 commands, or implicitly if a macro hook is triggered, e.g., a
2885 Note that interpretation of
2887 depends on how (i.e.,
2889 normal macro, folder hook, hook, account switch) the macro is invoked.
2890 Macros can be deleted via
2894 Macro behaviour, including option localization, will change in v15.
2895 Please be aware of that and possibly embed a version check in a resource
2900 (d) Marks the given message list as
2902 Deleted messages will neither be saved in
2904 nor will they be available for most other commands.
2916 Deletes the current message and displays the next message.
2917 If there is no next message, \*(UA says
2924 up or down by one message when given
2928 argument, respectively.
2932 Takes a message list and marks each given message as a draft.
2933 This mark has no technical meaning in the mail system;
2934 it just causes messages to be marked in the header summary,
2935 and makes them specially addressable.
2939 (ec) Echoes its arguments,
2940 resolving special names as documented for the command
2942 The escape sequences
2954 are interpreted just as they are by
2956 (proper quoting provided).
2960 (e) Point the text editor (as defined in
2962 at each message from the given list in turn.
2963 Modified contents are discarded unless the
2970 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2971 conditional \(em if the condition of a preceeding
2973 was false, check the following condition and execute the following block
2974 if it evaluates true.
2979 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2980 conditional \(em if none of the conditions of the preceeding
2984 commands was true, the
2990 (en) Marks the end of an
2991 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2992 conditional execution block.
2996 \*(OP Since \*(UA uses the console as a user interface it can happen
2997 that messages scroll by too fast to become recognized.
2998 Optionally an error message ring queue is available which stores
2999 duplicates of any error message and notifies the user in interactive
3000 sessions whenever a new error has occurred.
3001 The queue is finite: if its maximum size is reached any new message
3002 replaces the eldest.
3005 can be used to manage this message queue: if given
3007 or no argument the queue will be displayed and cleared,
3009 will only clear all messages from the queue.
3013 (ex or x) Exit from \*(UA without changing the active mailbox and skip
3014 any saving of messages in
3016 as well as a possibly tracked line editor history file.
3020 Show the list of features that have been compiled into \*(UA.
3021 (Outputs the contents of the variable
3028 but open the mailbox readonly.
3032 (fi) The file command switches to a new mailbox.
3033 Without arguments it shows status information of the current mailbox.
3034 If an argument is given, it will write out changes (such as deletions)
3035 the user has made and open a new mailbox.
3036 Some special conventions are recognized for the
3040 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
3042 (number sign) means the previous file,
3044 (percent sign) means the invoking user's system mailbox,
3046 means the system mailbox of
3048 (and never the value of
3050 regardless of its actual setting),
3052 (ampersand) means the invoking user's
3062 expands to the same value as
3064 but the file is handled as a system mailbox by, e.g., the
3068 commands, meaning that messages that have been read in the current
3069 session will be moved to the
3071 mailbox instead of simply being flagged as read.
3074 If the name matches one of the strings defined with the command
3076 it is replaced by its long form and expanded.
3077 If the name ends with
3082 it is treated as being compressed with
3087 respectively, and transparently handled through an intermediate
3088 (un)compression step (using a temporary file) with the according
3089 facility, sufficient support provided.
3090 Likewise, if the named file doesn't exist, but a file with one of the
3091 mentioned compression extensions does, then the name is automatically
3092 expanded and the compressed file is used.
3094 Otherwise, if the name ends with an extension for which
3095 .Va file-hook-load-EXTENSION
3097 .Va file-hook-save-EXTENSION
3098 variables are set, then the given hooks will be used to load and save
3100 and \*(UA will work with an intermediate temporary file.
3102 MBOX files (flat file-based mailboxes) are generally locked during file
3103 operations in order to avoid inconsistencies due to concurrent
3105 \*(OPal Mailbox files which \*(UA treats as system or primary mailboxes
3106 will also be protected by so-called dotlock files, the traditional way
3107 of mail spool file locking: for any file
3111 will be created for the duration of the synchronization \(em
3112 as necessary a privilege-separated dotlock child process will be used
3113 to accommodate for necessary privilege adjustments in order to create
3114 the dotlock file in the same directory
3115 and with the same user and group identities as the file of interest.
3118 for fine-tuning the handling of MBOX files.
3122 refers to a directory with the subdirectories
3127 then it is treated as a folder in
3132 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
3133 .Dl \*(OU protocol://[user@]host[:port][/path]
3135 is taken as an Internet mailbox specification.
3136 The \*(OPally supported protocols are
3140 (POP3 with SSL/TLS encrypted transport).
3143 part is valid only for IMAP; there it defaults to
3145 Also see the section
3146 .Sx "On URL syntax and credential lookup" .
3150 contains special characters, in particular
3154 they must be escaped in URL notation \(en the command
3156 can be used to show the necessary conversion.
3160 Takes a message list and marks the messages as
3162 ged for urgent/special attention.
3163 This mark has no technical meaning in the mail system;
3164 it just causes messages to be highlighted in the header summary,
3165 and makes them specially addressable.
3174 With no arguments, list the names of the folders in the folder directory.
3175 With an existing folder as an argument,
3176 lists the names of folders below the named folder.
3182 but saves the message in a file named after the local part of the first
3183 recipient's address (instead of in
3190 but saves the message in a file named after the local part of the first
3191 recipient's address (instead of in
3198 but responds to all recipients regardless of the
3203 .It Ic followupsender
3206 but responds to the sender only regardless of the
3222 (f) Takes a list of message specifications and displays a summary of
3223 their message headers, as via
3225 An alias of this command is
3228 .Sx "Specifying messages" .
3234 but saves the message in a file named after the local part of the
3235 recipient's address (instead of in
3240 Takes a message and the address of a recipient
3241 and forwards the message to him.
3242 The text of the original message is included in the new one,
3243 with the value of the
3245 variable preceding it.
3250 commands specify which header fields are included in the new message.
3251 Only the first part of a multipart message is included unless the
3252 .Va forward-as-attachment
3256 is set recipient addresses will be stripped from comments, names etc.
3260 Specifies which header fields are to be ignored with the command
3262 This command has no effect when the
3263 .Va forward-as-attachment
3268 Specifies which header fields are to be retained with the command
3273 This command has no effect when the
3274 .Va forward-as-attachment
3279 Define or list command aliases, so-called ghosts.
3280 Without arguments a list of all currently known aliases is shown.
3281 With one argument the expansion of the given alias is shown.
3282 With two or more arguments a command alias is defined or updated: the
3283 first argument is the name under which the remaining command line should
3284 be accessible, the content of which can be just about anything.
3285 A ghost can be used everywhere a normal command can be used, but always
3286 takes precedence; any arguments that are given to the command alias are
3287 joined onto the alias content, and the resulting string forms the
3288 command line that is, in effect, executed.
3291 .Bd -literal -offset indent
3293 `ghost': no such alias: "xx"
3296 ghost xx "echo hello,"
3305 (h) Show the current group of headers, the size of which depends on
3308 and the style of which can be adjusted with the variable
3310 If a message-specification is given the group of headers containing the
3311 first message therein is shown and the message at the top of the screen
3326 the list of history entries;
3329 argument selects and shows the respective history entry \(en
3332 to accept it, and the history entry will become the new history top.
3333 The default mode if no arguments are given is
3340 Takes a message list and marks each message therein to be saved in the
3341 user's system mailbox instead of in
3343 Does not override the
3346 \*(UA deviates from the POSIX standard with this command, because a
3348 command issued after
3350 will display the following message, not the current one.
3355 (i) Part of the nestable
3356 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3357 conditional execution construct \(em if the given condition is true then
3358 the encapsulated block is executed.
3359 POSIX only supports the (case-insensitive) conditions
3364 end, all remaining conditions are non-portable extensions; note that
3365 falsely specified conditions cause the execution of the entire
3366 conditional construct until the (matching) closing
3368 command to be suppressed.
3369 The syntax of the nestable
3371 conditional execution construct requires that each condition and syntax
3372 element is surrounded by whitespace.
3374 .Bd -literal -offset indent
3383 The (case-insensitive) condition
3385 erminal will evaluate to true if the standard input is a terminal, i.e.,
3386 in interactive sessions.
3387 Another condition can be any boolean value (see the section
3388 .Sx "INTERNAL VARIABLES"
3389 for textual boolean representations) to mark an enwrapped block as
3392 .Dq always execute .
3393 It is possible to check
3394 .Sx "INTERNAL VARIABLES"
3397 variables for existence or compare their expansion against a user given
3398 value or another variable by using the
3400 .Pf ( Dq variable next )
3401 conditional trigger character;
3402 a variable on the right hand side may be signalled using the same
3404 The variable names may be enclosed in a pair of matching braces.
3407 The available comparison operators are
3411 (less than or equal to),
3417 (greater than or equal to),
3421 (is substring of) and
3423 (is not substring of).
3424 The values of the left and right hand side are treated as strings and
3425 are compared 8-bit byte-wise, ignoring case according to the rules of
3426 the US-ASCII encoding (therefore, dependend on the active locale,
3427 possibly producing false results for strings in the locale encoding).
3428 Except for the substring checks the comparison will instead be performed
3429 arithmetically if both, the user given value as well as the variable
3430 content, can be parsed as numbers (integers).
3431 An unset variable is treated as the empty string.
3434 When the \*(OPal regular expression support is available, the additional
3440 They treat the right hand side as an extended regular expression that is
3441 matched case-insensitively and according to the active
3443 locale, meaning that strings in the locale encoding should be matched
3447 Conditions can be joined via AND-OR lists (where the AND operator is
3449 and the OR operator is
3451 which have equal precedence and will be evaluated with left
3452 associativity, thus using the same syntax that is known for the
3454 It is also possible to form groups of conditions and lists by enclosing
3455 them in pairs of brackets
3456 .Ql [\ \&.\&.\&.\ ] ,
3457 which may be interlocked within each other, and also be joined via
3461 The results of individual conditions and entire groups may be modified
3462 via unary operators: the unary operator
3464 will reverse the result.
3466 .Bd -literal -offset indent
3470 if $ttycharset == "UTF-8"
3471 echo *ttycharset* is set to UTF-8, case-insensitively
3475 echo These two variables are equal
3477 if $version-major >= 15
3478 echo Running a new version..
3479 if $features =@ "regex"
3480 if $TERM =~ "^xterm\&.*"
3481 echo ..in an X terminal
3484 if [ [ true ] && [ [ ${debug} ] || [ $verbose ] ] ]
3487 if true && $debug || ${verbose}
3488 echo Left associativity, as is known from the shell
3490 if ! ! true && ! [ ! $debug && ! $verbose ]
3491 echo Unary operator support
3499 Without arguments the list of ignored header fields is shown,
3500 otherwise the given list of header fields is added to the ignore list:
3501 Header fields in the ignore list are not shown on the terminal when
3502 a message is displayed.
3503 To display a message in its entirety, use the commands
3514 Shows the names of all available commands, alphabetically sorted.
3518 This command can be used to localize changes to variables, meaning that
3519 their state will be reverted to the former one once the covered scope
3521 It can only be used inside of macro definition blocks introduced by
3525 and is interpreted as a boolean (string, see
3526 .Sx "INTERNAL VARIABLES" ) ;
3529 of an account is left once it is switched off again.
3530 .Bd -literal -offset indent
3531 define temporary_settings {
3546 enables change localization and calls
3548 which explicitly resets localization, then any value changes within
3550 will still be reverted by
3555 Reply to messages that come in via known
3558 .Pf ( Ic mlsubscribe )
3559 mailing lists, or pretend to do so (see
3560 .Sx "Mailing lists" ) :
3563 functionality this will actively resort and even remove message
3564 recipients in order to generate a message that is supposed to be sent to
3566 For example it will also implicitly generate a
3567 .Ql Mail-Followup-To:
3568 header if that seems useful, regardless of the setting of the variable
3575 but saves the message in a file named after the local part of the first
3576 recipient's address (instead of in
3581 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3582 or asks on standard input if none were given;
3583 then collects the remaining mail content and sends it out.
3587 (mb) The given message list is to be sent to
3589 when \*(UA is quit; this is the default action unless the
3592 \*(ID This command can only be used in a system mailbox (see
3597 Without any arguments the content of the MIME type cache will displayed.
3598 Otherwise each argument defines a complete MIME type specification of
3599 a type that shall be added (prepended) to the cache.
3600 In any event MIME type sources are loaded first as necessary \(en
3601 .Va mimetypes-load-control
3602 can be used to fine-tune which sources are actually loaded.
3603 Refer to the section on
3604 .Sx "The mime.types files"
3605 for more on MIME type specifications and this topic in general.
3606 MIME type unregistration and cache resets can be triggered with
3611 Without arguments the list of all currently defined mailing lists
3612 (and their attributes, if any) is shown; a more verbose listing will be
3613 produced if either of
3618 Otherwise all given arguments (which need not be quoted except for
3619 whitespace) will be added and henceforth be recognized as mailing lists.
3620 Mailing lists may be removed via the command
3623 If the \*(OPal regular expression support is available then mailing
3624 lists may also be specified as (extended) regular expressions (see
3630 Without arguments the list of all currently defined mailing lists which
3631 have a subscription attribute is shown; a more verbose listing will be
3632 produced if either of
3637 Otherwise this attribute will be set for all given mailing lists,
3638 newly creating them as necessary (as via
3640 Subscription attributes may be removed via the command
3649 but moves the messages to a file named after the local part of the
3650 sender address of the first message (instead of in
3657 but marks the messages for deletion if they were transferred
3664 but also displays ignored header fields and all MIME parts.
3672 on the given messages, even in non-interactive mode and as long as the
3673 standard output is a terminal.
3679 \*(OP When used without arguments or if
3681 has been given the content of the
3683 cache is shown, loading it first as necessary,
3686 then the cache will only be initialized and
3688 will remove its contents.
3689 Note that \*(UA will try to load the file only once, use
3690 .Ql Ic \&\&netrc Ns \:\0\:clear
3691 to unlock further attempts.
3695 .Sx "On URL syntax and credential lookup" ;
3697 .Sx "The .netrc file"
3698 documents the file format in detail.
3702 Checks for new mail in the current folder without committing any changes
3704 If new mail is present, a message is shown.
3708 the headers of each new message are also shown.
3716 Goes to the next message in sequence and types it.
3717 With an argument list, types the next matching message.
3731 If the current folder is accessed via a network connection, a
3733 command is sent, otherwise no operation is performed.
3739 but also displays ignored header fields and all MIME parts.
3747 on the given messages, even in non-interactive mode and as long as the
3748 standard output is a terminal.
3756 but also pipes ignored header fields and all parts of MIME
3757 .Ql multipart/alternative
3762 (pi) Takes a message list and a shell command
3763 and pipes the messages through the command.
3764 Without an argument the current message is piped through the command
3771 every message is followed by a formfeed character.
3792 (q) Terminates the session, saving all undeleted, unsaved messages in
3795 preserving all messages marked with
3799 or never referenced in the system mailbox,
3800 and removing all other messages from the system mailbox.
3801 If new mail has arrived during the session,
3803 .Dq You have new mail
3805 If given while editing a mailbox file with the command line flag
3807 then the edit file is rewritten.
3808 A return to the shell is effected,
3809 unless the rewrite of edit file fails,
3810 in which case the user can escape with the exit command.
3824 Removes the named folders.
3825 The user is asked for confirmation in interactive mode.
3829 Takes the name of an existing folder
3830 and the name for the new folder
3831 and renames the first to the second one.
3832 Both folders must be of the same type.
3836 (R) Reply to originator.
3837 Does not reply to other recipients of the original message.
3839 will exchange this command with
3843 is set the recipient address will be stripped from comments, names etc.
3847 (r) Take a message and group-responds to it by addressing the sender
3850 .Va followup-to-honour ,
3853 .Va recipients-in-cc
3854 influence response behaviour.
3857 offers special support for replying to mailing lists.
3860 is set recipient addresses will be stripped from comments, names etc.
3873 but initiates a group-reply regardless of the value of
3880 but responds to the sender only regardless of the value of
3887 but does not add any header lines.
3888 This is not a way to hide the sender's identity,
3889 but useful for sending a message again to the same recipients.
3893 Takes a list of messages and a user name
3894 and sends each message to the named user.
3896 and related header fields are prepended to the new copy of the message.
3914 .It Ic respondsender
3920 (ret) Without arguments the list of retained header fields is shown,
3921 otherwise the given list of header fields is added to the retain list:
3922 Header fields in the retain list are shown on the terminal when
3923 a message is displayed, all other header fields are suppressed.
3924 To display a message in its entirety, use the commands
3933 takes precedence over the mentioned.
3939 but saves the messages in a file named after the local part of the
3940 sender of the first message instead of (in
3942 and) taking a filename argument.
3946 (s) Takes a message list and a filename and appends each message in turn
3947 to the end of the file.
3948 If no filename is given, the
3951 The filename in quotes, followed by the generated character count
3952 is echoed on the user's terminal.
3953 If editing a system mailbox the messages are marked for deletion.
3954 Filename interpretation as described for the
3956 command is performed.
3973 Header fields thus marked are filtered out when saving a message by
3975 or when automatically saving to
3977 This command should only be applied to header fields that do not contain
3978 information needed to decode the message,
3979 as MIME content fields do.
3991 Header fields thus marked are the only ones saved with a message when
3994 or when automatically saving to
3999 The use of this command is strongly discouraged since it may strip
4000 header fields that are needed to decode the message correctly.
4004 Takes a message specification (list) and displays a header summary of
4005 all matching messages, as via
4007 This command is an alias of
4010 .Sx "Specifying messages" .
4014 Takes a message list and marks all messages as having been read.
4018 (se) Without arguments this command shows all variables and their
4019 values which are currently known to \*(UA.
4020 Setting any of the variables
4024 changes the output format to BSD style, otherwise a properly quoted
4025 listing is produced.
4030 has been set twice then the listing is modified to mark out assembled
4033 Otherwise modifies (set and unsets) the given variables.
4034 Arguments are of the form
4036 (no space before or after
4040 if there is no value.
4041 Quotation marks may be placed around any part of the assignment
4042 statement to quote blanks or tabs, e.g.,
4044 .Dl set indentprefix="->"
4046 If an argument begins with
4050 the effect is the same as invoking the
4052 command with the remaining part of the variable
4053 .Pf ( Ql unset save ) .
4059 except that the variables are also exported into the program environment;
4060 since this task requires native host support the command will always
4061 report error if that is not available (but still act like
4064 This operation is a no-op unless all resource files have been loaded.
4070 (sh) Invokes an interactive version of the shell.
4074 Without arguments the list of all currently defined shortcuts is
4076 Otherwise all given arguments (which need not be quoted except for
4077 whitespace) are treated as pairs of shortcuts and their expansions,
4078 creating new or changing already existing shortcuts, as necessary.
4079 Shortcuts may be removed via the command
4081 The expansion strings should be in the syntax that has been described
4090 but performs neither MIME decoding nor decryption, so that the raw
4091 message text is shown.
4095 (si) Shows the size in characters of each message of the given
4100 Shows the current sorting criterion when used without an argument.
4101 Otherwise creates a sorted representation of the current folder,
4104 command and the addressing modes such that they refer to messages in
4106 Message numbers are the same as in regular mode.
4110 a header summary in the new order is also displayed.
4111 Automatic folder sorting can be enabled by setting the
4113 variable, as in, e.g.,
4114 .Ql set autosort=thread .
4115 Possible sorting criterions are:
4117 .Bl -tag -compact -offset indent -width "subject"
4119 Sort the messages by their
4121 field, that is by the time they were sent.
4123 Sort messages by the value of their
4125 field, that is by the address of the sender.
4128 variable is set, the sender's real name (if any) is used.
4130 Sort the messages by their size.
4132 \*(OP Sort the message by their spam score, as has been classified by
4135 Sort the messages by their message status.
4137 Sort the messages by their subject.
4139 Create a threaded display.
4141 Sort messages by the value of their
4143 field, that is by the address of the recipient.
4146 variable is set, the recipient's real name (if any) is used.
4151 (so) The source command reads commands from the given file, which is
4152 subject to the usual filename expansions (see introductional words of
4154 If the given argument ends with a vertical bar
4156 then the argument will instead be interpreted as a shell command and
4157 \*(UA will read the output generated by it.
4160 cannot be used from within macros that execute as
4161 .Va folder-hook Ns s
4164 i.e., it can only be called from macros that were
4171 (beside not supporting pipe syntax a.k.a. shell command input) is that
4172 this command will not generate an error if the given file argument
4173 cannot be opened successfully.
4174 This can matter in, e.g., resource files, since loading of those is
4175 stopped when an error is encountered.
4179 \*(OP Takes a list of messages and clears their
4185 \*(OP Takes a list of messages and causes the
4187 to forget it has ever used them to train its Bayesian filter.
4188 Unless otherwise noted the
4190 flag of the message is inspected to chose wether a message shall be
4198 \*(OP Takes a list of messages and informs the Bayesian filter of the
4202 This also clears the
4204 flag of the messages in question.
4208 \*(OP Takes a list of messages and rates them using the configured
4209 .Va spam-interface ,
4210 without modifying the messages, but setting their
4212 flag as appropriate; because the spam rating headers are lost the rate
4213 will be forgotten once the mailbox is left.
4214 Refer to the manual section
4216 for the complete picture of spam handling in \*(UA.
4220 \*(OP Takes a list of messages and sets their
4226 \*(OP Takes a list of messages and informs the Bayesian filter of the
4232 flag of the messages in question.
4241 Create a threaded representation of the current folder,
4242 i.\|e. indent messages that are replies to other messages in the header
4243 display and change the
4245 command and the addressing modes such that they refer to messages in the
4247 Message numbers are the same as in unthreaded mode.
4251 a header summary in threaded order is also displayed.
4255 (to) Takes a message list and displays the top few lines of each.
4256 The number of lines shown is controlled by the variable
4258 and defaults to five.
4262 (tou) Takes a message list and marks the messages for saving in
4264 \*(UA deviates from the POSIX standard with this command,
4267 command will display the following message instead of the current one.
4273 but also displays out ignored header fields and all parts of MIME
4274 .Ql multipart/alternative
4279 (t) Takes a message list and types out each message on the user's
4285 For MIME multipart messages, all parts with a content type of
4289 are shown, the other are hidden except for their headers.
4290 Messages are decrypted and converted to the terminal character set
4295 Delete all given accounts.
4296 An error message is shown if a given account is not defined.
4299 will discard all existing accounts.
4303 (una) Takes a list of names defined by alias commands
4304 and discards the remembered groups of users.
4307 will discard all existing aliases.
4311 Takes a message list and marks each message as not having been answered.
4315 Only applicable to threaded mode.
4316 Takes a message list and makes the message and all replies to it visible
4317 in header summaries again.
4318 When a message becomes the current message,
4319 it is automatically made visible.
4320 Also when a message with collapsed replies is displayed,
4321 all of these are automatically uncollapsed.
4327 mapping for the given colour type (see
4329 for a list of types) and mapping; if the optional precondition argument
4330 is used then only the exact tuple of mapping and precondition is removed.
4333 will remove all mappings (no precondition allowed).
4335 .Sx "Coloured display"
4336 for the general picture.
4340 Deletes the custom headers given as arguments.
4343 will remove all custom headers.
4347 Undefine all given macros.
4348 An error message is shown if a given macro is not defined.
4351 will discard all existing macros.
4355 (u) Takes a message list and marks each message as not being deleted.
4359 Takes a message list and
4365 Takes a message list and marks each message as not being
4370 Removes the header field names from the list of ignored fields for the
4375 will remove all fields.
4379 Removes the header field names from the list of retained fields for the
4384 will remove all fields.
4388 Remove all the given command
4392 will remove all ghosts.
4396 Removes the header field names from the list of ignored fields.
4399 will remove all fields.
4403 Delete all given MIME types, e.g.,
4404 .Ql unmimetype text/plain
4405 will remove all registered specifications for the MIME type
4409 will discard all existing MIME types, just as will
4411 but which also reenables cache initialization via
4412 .Va mimetypes-load-control .
4416 Forget about all the given mailing lists.
4419 will remove all lists.
4424 .It Ic unmlsubscribe
4425 Remove the subscription attribute from all given mailing lists.
4428 will clear the attribute from all lists which have it set.
4439 Takes a message list and marks each message as not having been read.
4443 Removes the header field names from the list of retained fields.
4446 will remove all fields.
4450 Removes the header field names from the list of ignored fields for
4454 will remove all fields.
4458 Removes the header field names from the list of retained fields for
4462 will remove all fields.
4466 (uns) Takes a list of option names and discards their remembered values;
4474 except that the variables are also removed from the program environment;
4475 since this task requires native host support the command will always
4476 report error if that is not available (but still act like
4479 This operation is a no-op unless all resource files have been loaded.
4485 Deletes the shortcut names given as arguments.
4488 will remove all shortcuts.
4492 Disable sorted or threaded mode
4498 return to normal message order and,
4502 displays a header summary.
4512 Decode the given URL-encoded string arguments and show the results.
4513 Note the resulting strings may not be valid in the current locale, see
4518 URL-encode the given arguments and show the results.
4519 Because the arguments effectively are in the character set of the
4520 current locale the results will vary accordingly unless the input solely
4521 consists of characters in the portable character set, see
4522 .Sx "Character sets" .
4526 Edit the values of or create the given variable(s) in the
4528 Boolean variables cannot be edited.
4532 Show informations about all the given variables.
4533 \*(UA knows about a finite set of known builtin variables that are
4534 subdivided further in boolean and value variants;
4535 they may have special properties, like
4537 (setting may not be changed) and
4539 meaning that the value is generated on-the-fly as necessary.
4540 Beside those known variables an infinite number of unknown, so-called
4542 variables, which are expected to be able to store values, may exist.
4543 .Bd -literal -offset indent
4545 ? varshow sendwait version-major foo bar
4546 "sendwait": (73) boolean: set=1 (ENVIRON=0)
4547 "version-major": (192) value, read-only, virtual:\e
4548 set=1 (ENVIRON=0) value<14>
4549 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4550 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4555 \*(OP Takes a message list and verifies each message.
4556 If a message is not a S/MIME signed message,
4557 verification will fail for it.
4558 The verification process checks if the message was signed using a valid
4560 if the message sender's email address matches one of those contained
4561 within the certificate,
4562 and if the message content has been altered.
4566 (v) Takes a message list and invokes the display editor on each message.
4567 Modified contents are discarded unless the
4573 (w) For conventional messages the body without all headers is written.
4574 The output is decrypted and converted to its native format as necessary.
4575 If the output file exists, the text is appended.
4576 If a message is in MIME multipart format its first part is written to
4577 the specified file as for conventional messages,
4578 and the user is asked for a filename to save each other part.
4579 For convience saving of each part may be skipped by giving an empty value;
4580 the same result can also be achieved by writing it to
4582 For the second and subsequent parts a leading
4584 character causes the part to be piped to the remainder of the user input
4585 interpreted as a shell command;
4586 otherwise the user input is expanded as usually for folders,
4587 e.g., tilde expansion is performed.
4588 In non-interactive mode, only the parts of the multipart message
4589 that have a filename given in the part header are written,
4590 the others are discarded.
4591 The original message is never marked for deletion in the originating
4594 the contents of the destination file are overwritten if the file
4596 No special handling of compressed files is performed.
4605 \*(UA presents message headers in windowfuls as described under the
4608 This command scrolls to the next window of messages.
4609 If an argument is given,
4610 it specifies the window to use.
4611 A number prefixed by
4615 indicates that the window is calculated in relation to the current position.
4616 A number without a prefix specifies an absolute window number,
4619 lets \*(UA scroll to the last window of messages.
4625 but scrolls to the next or previous window that contains at least one
4634 .\" .Sh TILDE ESCAPES {{{
4637 Here is a summary of the tilde escapes,
4638 which are used to perform special functions when composing messages.
4639 Tilde escapes are only recognized at the beginning of lines.
4642 is somewhat of a misnomer since the actual escape character can be
4643 changed by adjusting the option
4646 .Bl -tag -width ".Ic __ filename"
4649 Insert the string of text in the message prefaced by a single
4651 (If the escape character has been changed,
4652 that character must be doubled
4653 in order to send it at the beginning of a line.)
4656 .It Ic ~! Ar command
4657 Execute the indicated shell
4659 then return to the message.
4663 Same effect as typing the end-of-file character.
4666 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4667 Execute the given \*(UA command.
4668 Not all commands, however, are allowed.
4672 Write a summary of command escapes.
4675 .It Ic ~< Ar filename
4680 .It Ic ~<! Ar command
4682 is executed using the shell.
4683 Its standard output is inserted into the message.
4686 .It Ic ~@ Op Ar filename...
4687 With no arguments, edit the attachment list interactively.
4688 If an attachment's file name is left empty,
4689 that attachment is deleted from the list.
4690 When the end of the attachment list is reached,
4691 \*(UA will ask for further attachments until an empty name is given.
4692 If a given file name solely consists of the number sign
4694 followed by a valid message number of the currently active mailbox, then
4695 the given message is attached as a MIME
4697 and the rest of this section does not apply.
4699 If character set conversion has been compiled into \*(UA, then this mode
4700 gives the user the option to specify input and output character sets,
4701 unless the file extension indicates binary content, in which case \*(UA
4702 asks wether this step shall be skipped for the attachment in question.
4703 If not skipped, then the charset that succeeds to represent the
4704 attachment data will be used in the
4706 MIME parameter of the mail message:
4708 .Bl -bullet -compact
4710 If input and output character sets are specified, then the conversion is
4711 performed on the fly.
4712 The user will be asked repeatedly until the desired conversion succeeds.
4714 If only an output character set is specified, then the input is assumed
4717 charset and will be converted to the given output charset on the fly.
4718 The user will be asked repeatedly until the desired conversion succeeds.
4720 If no character sets are specified at all then the algorithm that is
4721 documented in the section
4722 .Sx "Character sets"
4723 is applied, but directly and on the fly.
4724 The user will be asked repeatedly until the desired conversion succeeds.
4726 Finally, if an input-, but no output character set is specified, then no
4727 conversion is ever performed, but the
4729 MIME parameter value will still be set to the user input.
4731 The character set selection loop can be left by typing
4733 i.e., causing an interrupt.
4734 .\" \*(OU next sentence
4735 Note that before \*(UA version 15.0 this terminates the entire
4736 current attachment selection, not only the character set selection.
4739 Without character set conversion support, \*(UA will ask for the input
4740 character set only, and it'll set the
4742 MIME parameter value to the given input, if any;
4743 if no user input is seen then the
4745 character set will be used for the parameter value instead.
4746 Note that the file extension check isn't performed in this mode, since
4747 no conversion will take place anyway.
4749 Note that in non-interactive mode, for reproduceabilities sake, there
4750 will always be two questions for each attachment, regardless of wether
4751 character set conversion is available and what the file extension is.
4752 The first asks for the filename, and the second asks for the input
4753 character set to be passed through to the corresponding MIME parameter;
4754 no conversion will be tried if there is input to the latter question,
4755 otherwise the usual conversion algorithm, as above, is applied.
4756 For message attachments, the answer to the second question is completely
4761 arguments are specified for the
4763 command they are treated as a comma-separated list of files,
4764 which are all expanded and appended to the end of the attachment list.
4765 (Commas need to be escaped with backslash, but filenames with leading or
4766 trailing whitespace can only be added via the command line or the first
4768 Message attachments can only be added via the first method;
4769 filenames which clash with message numbers can only be added via the
4770 command line or the second method.)
4771 In this mode the (text) attachments are assumed to be in
4773 encoding, and will be evaluated as documented in the section
4774 .Sx "Character sets" .
4778 Inserts the string contained in the
4781 .Ql Ic ~i Ns \0Sign ) .
4782 The escape sequences tabulator
4790 Inserts the string contained in the
4793 .Ql Ic ~i Ns \0sign ) .
4794 The escape sequences tabulator
4801 .It Ic ~b Ar name ...
4802 Add the given names to the list of blind carbon copy recipients.
4805 .It Ic ~c Ar name ...
4806 Add the given names to the list of carbon copy recipients.
4810 Read the file specified by the
4812 variable into the message.
4816 Invoke the text editor on the message collected so far.
4817 After the editing session is finished,
4818 the user may continue appending text to the message.
4821 .It Ic ~F Ar messages
4822 Read the named messages into the message being sent, including all
4823 message headers and MIME parts.
4824 If no messages are specified, read in the current message.
4827 .It Ic ~f Ar messages
4828 Read the named messages into the message being sent.
4829 If no messages are specified, read in the current message.
4833 lists are used to modify the message headers.
4834 For MIME multipart messages,
4835 only the first displayable part is included.
4839 Edit the message header fields
4844 by typing each one in turn and allowing the user to edit the field.
4845 The default values for these fields originate from the
4853 Edit the message header fields
4859 by typing each one in turn and allowing the user to edit the field.
4862 .It Ic ~i Ar variable
4863 Insert the value of the specified variable into the message,
4864 adding a newline character at the end.
4865 The message remains unaltered if the variable is unset or empty.
4866 The escape sequences tabulator
4873 .It Ic ~M Ar messages
4874 Read the named messages into the message being sent,
4877 If no messages are specified, read the current message.
4880 .It Ic ~m Ar messages
4881 Read the named messages into the message being sent,
4884 If no messages are specified, read the current message.
4888 lists are used to modify the message headers.
4889 For MIME multipart messages,
4890 only the first displayable part is included.
4894 Display the message collected so far,
4895 prefaced by the message header fields
4896 and followed by the attachment list, if any.
4900 Abort the message being sent,
4901 copying it to the file specified by the
4908 .It Ic ~R Ar filename
4909 Read the named file into the message, indented by
4913 .It Ic ~r Ar filename
4914 Read the named file into the message.
4918 Cause the named string to become the current subject field.
4921 .It Ic ~t Ar name ...
4922 Add the given name(s) to the direct recipient list.
4925 .It Ic ~U Ar messages
4926 Read in the given / current message(s) excluding all headers, indented by
4930 .It Ic ~u Ar messages
4931 Read in the given / current message(s), excluding all headers.
4935 Invoke an alternate editor (defined by the
4937 option) on the message collected so far.
4938 Usually, the alternate editor will be a screen editor.
4939 After the editor is quit,
4940 the user may resume appending text to the end of the message.
4943 .It Ic ~w Ar filename
4944 Write the message onto the named file.
4946 the message is appended to it.
4952 except that the message is not saved at all.
4955 .It Ic ~| Ar command
4956 Pipe the message through the specified filter command.
4957 If the command gives no output or terminates abnormally,
4958 retain the original text of the message.
4961 is often used as a rejustifying filter.
4966 .\" .Sh INTERNAL VARIABLES {{{
4967 .Sh "INTERNAL VARIABLES"
4969 Internal \*(UA variables are controlled via the
4973 commands; prefixing a variable name with the string
4977 has the same effect as using
4983 Creation or editing of variables can be performed in the
4988 will give more insight on the given variable(s), and
4990 when called without arguments, will show a listing of all variables.
4991 Variables are also implicitly inherited from the program
4993 and can be set explicitly via the command line option
4997 Two different kind of variables exist.
4998 There are boolean variables, which can only be in one of the two states
5002 and value variables with a(n optional) string value.
5003 For the latter proper quoting is necessary upon assignment time:
5004 To embed whitespace (space and tabulator) in a value it either needs to
5005 be escaped with a backslash character, or the entire value must be
5006 enclosed in (double or single) quotation marks;
5007 To use quotation marks identical to those used to enclose the value,
5008 escape them with a backslash character.
5009 The backslash character has no special meaning except in these cases.
5011 .Bd -literal -offset indent
5012 set one=val\e 1 two="val 2" \e
5013 three='val "3"' four='val \e'4\e''
5014 varshow one two three four
5015 unset one two three four
5019 Dependent upon the actual option the string values will be interpreted
5020 as numbers, colour names, normal text etc., but there also exists
5021 a special kind of string value, the
5022 .Dq boolean string ,
5023 which must either be a decimal integer (in which case
5027 and any other value is true) or any of the (case-insensitive) strings
5032 for a false boolean and
5037 for a true boolean; a special kind of boolean string is the
5039 which is a boolean string that can optionally be prefixed with the
5040 (case-insensitive) term
5044 which causes prompting of the user in interactive mode, with the given
5045 boolean as the default value.
5047 .\" .Ss "Initial settings" {{{
5048 .\" (Keep in SYNC: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
5049 .Ss "Initial Settings"
5051 The standard POSIX 2008/Cor 1-2013 mandates the following initial
5057 .Pf no Va autoprint ,
5071 .Pf no Va ignoreeof ,
5073 .Pf no Va keepsave ,
5075 .Pf no Va outfolder ,
5080 (note that \*(UA deviates from the standard by using
5084 special prompt escape results in
5092 .Pf no Va sendwait ,
5101 Notes: \*(UA doesn't support the
5103 variable \(en use command line options or
5104 .Va sendmail-arguments
5105 to pass options through to a MTA.
5106 And the default global
5108 file (which is loaded unless the
5110 command line flag has been used or the
5111 .Ev NAIL_NO_SYSTEM_RC
5112 environment variable is set) bends those initial settings a bit, e.g.,
5113 it sets the variables
5118 to name a few, calls
5120 etc., and should thus be taken into account.
5123 .\" .Ss "Variables" {{{
5126 .Bl -tag -width ".It Va _utoprin_"
5128 .It Va add-file-recipients
5129 \*(BO When file or pipe recipients have been specified,
5130 mention them in the corresponding address fields of the message instead
5131 of silently stripping them from their recipient list.
5132 By default such addressees are not mentioned.
5134 .Mx Va agent-shell-lookup
5135 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5137 \*(IN\*(OP Account passwords can be fetched via an external agent
5138 program in order to permit encrypted password storage \(en see
5139 .Sx "On URL syntax and credential lookup"
5140 for more on credential lookup.
5141 If this is set then the content is interpreted as a shell command the
5142 output of which (with newline characters removed) is treated as the
5143 account password shall the command succeed (and have produced non-empty
5144 non-newline output); e.g., via
5146 .Bd -literal -offset indent
5147 $ echo PASSWORD > .pass
5149 $ eval `gpg-agent --daemon \e
5150 --pinentry-program=/usr/bin/pinentry-curses \e
5151 --max-cache-ttl 99999 --default-cache-ttl 99999`
5152 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5156 A couple of environment variables will be set for the agent:
5158 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5160 The temporary directory that \*(UA uses.
5161 Usually identical to
5163 but guaranteed to be set and usable by child processes;
5164 to ensure the latter condition for
5170 for which the password is looked up.
5171 .It Ev NAIL_USER_ENC
5172 The URL percent-encoded variant of
5175 The plain machine hostname of the user account.
5176 .It Ev NAIL_HOST_PORT
5179 (hostname possibly including port) of the user account.
5184 \*(BO Causes only the local part to be evaluated
5185 when comparing addresses.
5189 \*(BO Causes messages saved in
5191 to be appended to the end rather than prepended.
5192 This should always be set.
5196 \*(BO Causes \*(UA to prompt for the subject of each message sent.
5197 If the user responds with simply a newline,
5198 no subject field will be sent.
5202 \*(BO Causes the prompts for
5206 lists to appear after the message has been edited.
5210 \*(BO If set, \*(UA asks for files to attach at the end of each message,
5211 shall the list be found empty at that time.
5212 An empty line finalizes the list.
5216 \*(BO Causes the user to be prompted for carbon copy recipients
5217 (at the end of each message if
5221 are set) shall the list be found empty (at that time).
5222 An empty line finalizes the list.
5226 \*(BO Causes the user to be prompted for blind carbon copy
5227 recipients (at the end of each message if
5231 are set) shall the list be found empty (at that time).
5232 An empty line finalizes the list.
5236 \*(BO\*(OP Causes the user to be prompted if the message is to be
5237 signed at the end of each message.
5240 variable is ignored when this variable is set.
5244 \*(BO Alternative name for
5251 .It Va attachment-ask-content-description , \
5252 attachment-ask-content-disposition , \
5253 attachment-ask-content-id , \
5254 attachment-ask-content-type
5255 \*(BO If set then the user will be prompted for some attachment
5256 information when editing the attachment list.
5257 It is advisable to not use these but for the first of the variables;
5258 even for that it has to be noted that the data is used
5264 A sequence of characters to display in the
5268 as shown in the display of
5270 each for one type of messages (see
5271 .Sx "Message states" ) ,
5272 with the default being
5275 .Ql NU\ \ *HMFAT+\-$~
5278 variable is set, in the following order:
5280 .Bl -tag -compact -offset indent -width ".It Ql _"
5302 start of a collapsed thread.
5304 an uncollapsed thread (TODO ignored for now).
5308 classified as possible spam.
5314 Specifies a list of recipients to which a blind carbon copy of each
5315 outgoing message will be sent automatically.
5319 Specifies a list of recipients to which a carbon copy of each outgoing
5320 message will be sent automatically.
5324 \*(BO Causes threads to be collapsed automatically when threaded mode
5331 \*(BO Causes the delete command to behave like
5333 thus, after deleting a message the next one will be typed automatically.
5337 \*(BO\*(OB Causes threaded mode (see the
5339 command) to be entered automatically when a folder is opened.
5341 .Ql autosort=thread .
5345 Causes sorted mode (see the
5347 command) to be entered automatically with the value of this option as
5348 sorting method when a folder is opened, e.g.,
5349 .Ql set autosort=thread .
5353 \*(BO Enables the substitution of
5355 by the contents of the last command line in shell escapes.
5358 .It Va batch-exit-on-error
5359 \*(BO If the batch mode has been enabled via the
5361 command line option, then this variable will be consulted whenever \*(UA
5362 completes one operation (returns to the command prompt); if it is set
5363 then \*(UA will terminate if the last operation generated an error.
5367 \*(BO Causes automatic display of a header summary after executing a
5373 \*(BO Sets some cosmetical features to traditional BSD style;
5374 has the same affect as setting
5376 and all other variables prefixed with
5378 it also changes the meaning of the \*(UA specific
5381 escape sequence and changes behaviour of
5383 (which doesn't exist in BSD).
5387 \*(BO Changes the letters shown in the first column of a header
5388 summary to traditional BSD style.
5392 \*(BO Changes the display of columns in a header summary to traditional
5397 \*(BO Changes some informational messages to traditional BSD style.
5403 field to appear immediately after the
5405 field in message headers and with the
5407 .Sx "TILDE ESCAPES" .
5411 \*(BO Changes the output format of the
5413 command to traditional BSD style.
5417 The value that should appear in the
5421 MIME header fields when no character set conversion of the message data
5423 This defaults to US-ASCII, and the chosen character set should be
5424 US-ASCII compatible.
5428 \*(OP The default 8-bit character set that is used as an implicit last
5429 member of the variable
5431 This defaults to UTF-8.
5432 If no character set conversion capabilities are available in \*(UA then
5433 the only supported character set is
5435 Refer to the section
5436 .Sx "Character sets"
5437 for the complete picture of character set conversion in \*(UA.
5440 .It Va charset-unknown-8bit
5441 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5443 the content of a mail message by using a character set with the name
5445 Because of the unclassified nature of this character set \*(UA will not
5446 be capable to convert this character set to any other character set.
5447 If this variable is set any message part which uses the character set
5449 is assumed to really be in the character set given in the value,
5450 otherwise the (final) value of
5452 is used for this purpose.
5454 This variable will also be taken into account if a MIME type (see
5455 .Sx "The mime.types files" )
5456 of a MIME message part that uses the
5458 character set is forcefully treated as text.
5462 The default value for the
5467 .It Va colour-disable
5468 \*(BO\*(OP Forcefully disable usage of colours.
5469 Also see the section
5470 .Sx "Coloured display" .
5474 \*(BO\*(OP Wether colour shall be used for output that is paged through
5476 Note that pagers may need special flags, e.g.,
5484 in order to support colours.
5485 Often doing manual adjustments is unnecessary since \*(UA may perform
5486 adjustments dependend on the value of the environment variable
5488 (see there for more).
5492 In a(n interactive) terminal session, then if this valued option is set
5493 it'll be used as a threshold to determine how many lines the given
5494 output has to span before it will be displayed via the configured
5498 can be forced by setting this to the value
5500 setting it without a value will deduce the current height of the
5501 terminal screen to compute the treshold (see
5509 \*(OB A variable counterpart of the
5511 command (see there for documentation), interpreted as a comma-separated
5512 list of custom headers to be injected, to include commas in the header
5513 bodies escape them with backslash, e.g.:
5515 .Dl set customhdr="Hdr1: Body1-1\e, Body1-2, Hdr2: Body2"
5521 the message date, if any is to be displayed according to the format of
5523 is by default taken from the
5525 line of the message.
5526 If this variable is set the date as given in the
5528 header field is used instead, converted to local time.
5529 To control the display format of the date assign a valid
5534 format should not be used, because \*(UA doesn't take embedded newlines
5535 into account when calculating how many lines fit onto the screen.)
5537 .Va datefield-markout-older .
5540 .It Va datefield-markout-older
5541 This option, when set in addition to
5545 messages (concept is rather comparable to the
5547 option of the POSIX utility
5549 The content interpretation is identical to
5554 \*(BO Enables debug messages and obsoletion warnings, disables the
5555 actual delivery of messages and also implies
5561 .It Va disposition-notification-send
5563 .Ql Disposition-Notification-To:
5564 header (RFC 3798) with the message.
5568 .\" TODO .It Va disposition-notification-send-HOST
5570 .\".Va disposition-notification-send
5571 .\" for SMTP accounts on a specific host.
5572 .\" TODO .It Va disposition-notification-send-USER@HOST
5574 .\".Va disposition-notification-send
5575 .\"for a specific account.
5579 \*(BO When dot is set, a period
5581 on a line by itself during message input in (interactive) compose mode
5582 will be treated as end-of-message (in addition to the normal end-of-file
5591 .It Va dotlock-ignore-error
5592 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5593 mailboxes (see the command
5595 will be protected with so-called dotlock files\(emthe traditional mail
5596 spool file locking method\(emin addition to system file locking.
5597 Because \*(UA ships with a privilege-separated dotlock creation program
5598 that should always be able to create such a dotlock file there is no
5599 good reason to ignore dotlock file creation errors, and thus these are
5600 fatal unless this variable is set.
5604 \*(BO If this variable is set then the editor is started automatically
5605 when a message is composed in interactive mode, as if the
5611 variable is implied for this automatically spawned editor session.
5615 \*(BO When a message is edited while being composed,
5616 its header is included in the editable text.
5626 fields are accepted within the header, other fields are ignored.
5630 \*(BO When entering interactive mode \*(UA normally writes
5631 .Dq \&No mail for user
5632 and exits immediately if a mailbox is empty or doesn't exist.
5633 If this option is set \*(UA starts even with an empty or nonexistent
5634 mailbox (the latter behaviour furtherly depends upon
5640 Suggestion for the MIME encoding to use in outgoing text messages
5642 Valid values are the default
5643 .Ql quoted-printable ,
5648 may cause problems when transferring mail messages over channels that
5649 are not ESMTP (RFC 1869) compliant.
5650 If there is no need to encode a message,
5652 transfer mode is always used regardless of this variable.
5653 Binary data is always encoded as
5658 If defined, the first character of this option
5659 gives the character to use in place of
5662 .Sx "TILDE ESCAPES" .
5666 If not set then file and command pipeline targets are not allowed,
5667 and any such address will be filtered out, giving a warning message.
5668 If set without a value then all possible recipient address
5669 specifications will be accepted \(en see the section
5670 .Sx "On sending mail, and non-interactive mode"
5672 To accept them, but only in interactive mode, or when tilde commands
5673 were enabled explicitly by using one of the command line options
5677 set this to the (case-insensitive) value
5679 (note right now this is actually like setting
5680 .Ql restrict,-all,+name,+addr ) .
5682 In fact the value is interpreted as a comma-separated list of values.
5685 then the existence of disallowed specifications is treated as a hard
5686 send error instead of only filtering them out.
5687 The remaining values specify wether a specific type of recipient
5688 address specification is allowed (optionally indicated by a plus sign
5690 prefix) or disallowed (prefixed with a hyphen
5694 addresses all possible address specifications,
5698 command pipeline targets,
5700 plain user names and (MTA) aliases (\*(OB
5702 may be used as an alternative syntax to
5707 These kind of values are interpreted in the given order, so that
5708 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5709 will cause hard errors for any non-network address recipient address
5710 unless \*(UA is in interactive mode or has been started with the
5714 command line option; in the latter case(s) any address may be used, then.
5718 Unless this variable is set additional mail-transfer-agent (MTA)
5719 arguments from the command line, as can be given after a
5721 separator, are ignored due to safety reasons.
5722 However, if set to the special (case-insensitive) value
5724 then the presence of additional MTA arguments is treated as a hard
5725 error that causes \*(UA to exit with failure status.
5726 A lesser strict variant is the otherwise identical
5728 which does accept such arguments in interactive mode, or if tilde
5729 commands were enabled explicitly by using one of the command line options
5736 \*(RO Information on the features compiled into \*(UA \(en the content
5737 of this variable is identical to the output of the command
5742 \*(BO This option reverses the meanings of a set of reply commands,
5743 turning the lowercase variants, which by default address all recipients
5744 included in the header of a message
5745 .Pf ( Ic reply , respond , followup )
5746 into the uppercase variants, which by default address the sender only
5747 .Pf ( Ic Reply , Respond , Followup )
5750 .Ic replysender , respondsender , followupsender
5752 .Ic replyall , respondall , followupall
5753 are not affected by the current setting of
5758 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5759 It is possible to install file hooks which will be used by the
5761 command in order to be able to transparently handle (through an
5762 intermediate temporary file) files with specific
5764 s: the variable values can include shell snippets and are expected to
5765 write data to standard output / read data from standard input,
5767 \*(ID The variables may not be changed while there is a mailbox
5769 .Bd -literal -offset indent
5770 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5771 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5772 record=+null-sent.xy
5777 The name of the directory to use for storing folders of messages.
5778 All folder names that begin with
5780 refer to files below it.
5781 The same special conventions as documented for the
5783 command may be used when specifying a new value for
5785 but be aware that the expansion is fully performed immediately.
5789 This variable can be set to the name of a
5791 macro which will be called whenever a
5794 The macro will also be invoked when new mail arrives,
5795 but message lists for commands executed from the macro
5796 only include newly arrived messages then.
5798 are activated by default in a folder hook, causing the covered settings
5799 to be reverted once the folder is left again.
5802 Macro behaviour, including option localization, will change in v15.
5803 Please be aware of that and possibly embed a version check in a resource
5807 .It Va folder-hook-FOLDER
5812 Unlike other folder specifications, the fully expanded name of a folder,
5813 without metacharacters, is used to avoid ambiguities.
5814 However, if the mailbox resides under
5818 specification is tried in addition, e.g., if
5822 (and thus relative to the user's home directory) then
5823 .Pa /home/usr1/mail/sent
5825 .Ql folder-hook-/home/usr1/mail/sent
5826 first, but then followed by
5827 .Ql folder-hook-+sent .
5831 \*(BO Controls wether a
5832 .Ql Mail-Followup-To:
5833 header is generated when sending messages to known mailing lists.
5835 .Va followup-to-honour
5837 .Ic mlist , mlsubscribe , reply
5842 .It Va followup-to-honour
5844 .Ql Mail-Followup-To:
5845 header is honoured when group-replying to a message via
5849 This is a quadoption; if set without a value it defaults to
5859 .It Va forward-as-attachment
5860 \*(BO Original messages are normally sent as inline text with the
5863 and only the first part of a multipart message is included.
5864 With this option messages are sent as unmodified MIME
5866 attachments with all of their parts included.
5870 The address (or a list of addresses) to put into the
5872 field of the message header, quoting RFC 5322:
5873 the author(s) of the message, that is, the mailbox(es) of the person(s)
5874 or system(s) responsible for the writing of the message.
5875 If replying to messages these addresses are handled as if they were in
5879 If the machine's hostname is not valid at the Internet (for example at
5880 a dialup machine) then either this variable or
5885 adds even more fine-tuning capabilities),
5889 contains more than one address,
5892 variable is required (according to the standard RFC 5322).
5896 \*(BO When replying to or forwarding a message \*(UA normally removes
5897 the comment and name parts of email addresses.
5898 If this variable is set such stripping is not performed,
5899 and comments, names etc. are retained.
5903 The string to put before the text of a message with the
5907 .Va forward-as-attachment
5910 .Dq -------- Original Message --------
5911 if unset; No heading is put if it is set to the empty string.
5915 \*(BO Causes the header summary to be written at startup and after
5916 commands that affect the number of messages or the order of messages in
5917 the current folder; enabled by default.
5918 The command line option
5926 A format string to use for the summary of
5928 similar to the ones used for
5931 Format specifiers in the given string start with a percent character
5933 and may be followed by an optional decimal number indicating the field
5934 width \(em if that is negative, the field is to be left-aligned.
5935 Valid format specifiers are:
5938 .Bl -tag -compact -offset indent -width "_%%_"
5940 A plain percent character.
5943 a space character but for the current message
5945 for which it expands to
5949 a space character but for the current message
5951 for which it expands to
5954 \*(OP The spam score of the message, as has been classified via the
5957 Shows only a replacement character if there is no spam support.
5959 Message attribute character (status flag); the actual content can be
5963 The date when the message was received, or the date found in the
5967 variable is set (optionally to a date display format string).
5969 The indenting level in threaded mode.
5971 The address of the message sender.
5973 The message thread tree structure.
5974 (Note that this format doesn't support a field width.)
5976 The number of lines of the message, if available.
5980 The number of octets (bytes) in the message, if available.
5982 Message subject (if any).
5984 Message subject (if any) in double quotes.
5986 Message recipient flags: is the addressee of the message a known or
5987 subscribed mailing list \(en see
5992 The position in threaded/sorted order.
5996 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
5998 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
6009 .It Va headline-bidi
6010 Bidirectional text requires special treatment when displaying headers,
6011 because numbers (in dates or for file sizes etc.) will not affect the
6012 current text direction, in effect resulting in ugly line layouts when
6013 arabic or other right-to-left text is to be displayed.
6014 On the other hand only a minority of terminals is capable to correctly
6015 handle direction changes, so that user interaction is necessary for
6017 Note that extended host system support is required nonetheless, e.g.,
6018 detection of the terminal character set is one precondition;
6019 and this feature only works in an Unicode (i.e., UTF-8) locale.
6021 In general setting this variable will cause \*(UA to encapsulate text
6022 fields that may occur when displaying
6024 (and some other fields, like dynamic expansions in
6026 with special Unicode control sequences;
6027 it is possible to fine-tune the terminal support level by assigning
6029 no value (or any value other than
6034 will make \*(UA assume that the terminal is capable to properly deal
6035 with Unicode version 6.3, in which case text is embedded in a pair of
6036 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6038 In addition no space on the line is reserved for these characters.
6040 Weaker support is chosen by using the value
6042 (Unicode 6.3, but reserve the room of two spaces for writing the control
6043 sequences onto the line).
6048 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6049 again reserves room for two spaces in addition.
6053 \*(OP If a line editor is available then this can be set to
6054 name the (expandable) path of the location of a permanent history file.
6057 .It Va history-gabby
6058 \*(BO\*(OP Add more entries to the history as is normally done.
6061 .It Va history-gabby-persist
6062 \*(BO\*(OP \*(UA's own MLE will not save the additional
6064 entries in persistent storage unless this variable is set.
6065 On the other hand it will not loose the knowledge of wether a persistent
6066 entry was gabby or not.
6072 \*(OP If a line editor is available this value restricts the
6073 amount of history entries that are saved into a set and valid
6075 A value of less than 0 disables this feature;
6076 note that loading and incorporation of
6078 upon program startup can also be suppressed by doing this.
6079 An unset or invalid value, or 0, causes a default value to be used.
6080 Dependent on the available line editor this will also define the
6081 number of history entries in memory;
6082 it is also editor-specific wether runtime updates of this value will be
6087 \*(BO This option is used to hold messages in the system mailbox,
6088 and it is set by default.
6092 Use this string as hostname when expanding local addresses instead of
6093 the value obtained from
6104 transport is not used then it is normally the responsibility of the MTA
6105 to create these fields, \*(IN in conjunction with
6109 also influences the results;
6110 you should produce some test messages with the desired combination of
6119 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
6120 names according to the rules of IDNA (internationalized domain names
6122 Since the IDNA code assumes that domain names are specified with the
6124 character set, an UTF-8 locale charset is required to represent all
6125 possible international domain names (before conversion, that is).
6129 \*(BO Ignore interrupt signals from the terminal while entering
6130 messages; instead echo them as
6132 characters and discard the current line.
6136 \*(BO Ignore end-of-file conditions
6137 .Pf ( Ql control-D )
6138 in compose mode on message input and in interactive command input.
6139 If set an interactive command input session can only be left by
6140 explicitly using one of the commands
6144 and message input in compose mode can only be terminated by entering
6147 on a line by itself or by using the
6149 .Sx "TILDE ESCAPES" ;
6151 overrides a setting of
6163 option for indenting messages,
6164 in place of the normal tabulator character
6166 which is the default.
6167 Be sure to quote the value if it contains spaces or tabs.
6171 \*(BO If set, an empty mailbox file is not removed.
6172 This may improve the interoperability with other mail user agents
6173 when using a common folder directory, and prevents malicious users
6174 from creating fake mailboxes in a world-writable spool directory.
6175 Note this only applies to local regular (MBOX) files, other mailbox
6176 types will never be removed.
6179 .It Va keep-content-length
6180 \*(BO When (editing messages and) writing
6182 mailbox files \*(UA can be told to keep the
6186 header fields that some MUAs generate by setting this variable.
6187 Since \*(UA does neither use nor update these non-standardized header
6188 fields (which in itself shows one of their conceptual problems),
6189 stripping them should increase interoperability in between MUAs that
6190 work with with same mailbox files.
6191 Note that, if this is not set but
6192 .Va writebackedited ,
6193 as below, is, a possibly performed automatic stripping of these header
6194 fields already marks the message as being modified.
6198 \*(BO When a message is saved it is usually discarded from the
6199 originating folder when \*(UA is quit.
6200 Setting this option causes all saved message to be retained.
6203 .It Va line-editor-disable
6204 \*(BO Turn off any enhanced line editing capabilities (see
6205 .Sx "On terminal control and line editor"
6210 \*(BO When a message is replied to and this variable is set,
6211 it is marked as having been answered.
6212 This mark has no technical meaning in the mail system;
6213 it just causes messages to be marked in the header summary,
6214 and makes them specially addressable.
6218 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6220 Messages which are fetched over the network or from within already
6221 existing Maildir (or any non-MBOX) mailboxes may require so-called
6223 quoting (insertion of additional
6225 characters to prevent line content misinterpretation) to be applied in
6226 order to be storable in MBOX mailboxes, however, dependent on the
6227 circumspection of the message producer.
6228 (E.g., \*(UA itself will, when newly generating messages, choose a
6229 .Pf Content-Transfer- Va encoding
6230 that prevents the necessity for such quoting \(en a necessary
6231 precondition to ensure message checksums won't change.)
6233 By default \*(UA will perform this
6235 quoting in a way that results in a MBOX file that is compatible with
6236 the POSIX MBOX layout, which means that, in order not to exceed the
6237 capabilities of simple applications, many more
6239 lines get quoted (thus modified) than necessary according to RFC 4155.
6240 Set this option to instead generate MBOX files which comply to RFC 4155.
6244 \*(BO Internal development variable.
6247 .It Va message-id-disable
6248 \*(BO By setting this option the generation of
6250 can be completely suppressed, effectively leaving this task up to the
6251 mail-transfer-agent (MTA) or the SMTP server.
6252 (According to RFC 5321 your SMTP server is not required to add this
6253 field by itself, so you should ensure that it accepts messages without a
6257 .It Va message-inject-head
6258 A string to put at the beginning of each new message.
6259 The escape sequences tabulator
6266 .It Va message-inject-tail
6267 A string to put at the end of each new message.
6268 The escape sequences tabulator
6276 \*(BO Usually, when an
6278 expansion contains the sender, the sender is removed from the expansion.
6279 Setting this option suppresses these removals.
6284 option to be passed to mail-transfer-agents (MTAs);
6285 though most of the modern MTAs don't (no longer) document this flag, no
6286 MTA is known which doesn't support it (for historical compatibility).
6289 .It Va mime-allow-text-controls
6290 \*(BO When sending messages, each part of the message is MIME-inspected
6291 in order to classify the
6294 .Ql Content-Transfer-Encoding:
6297 that is required to send this part over mail transport, i.e.,
6298 a computation rather similar to what the
6300 command produces when used with the
6304 This classification however treats text files which are encoded in
6305 UTF-16 (seen for HTML files) and similar character sets as binary
6306 octet-streams, forcefully changing any
6311 .Ql application/octet-stream :
6312 If that actually happens a yet unset charset MIME parameter is set to
6314 effectively making it impossible for the receiving MUA to automatically
6315 interpret the contents of the part.
6317 If this option is set, and the data was unambiguously identified as text
6318 data at first glance (by a
6322 file extension), then the original
6324 will not be overwritten.
6327 .It Va mime-alternative-favour-rich
6328 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6329 HTML) will be preferred in favour of included plain text versions when
6330 displaying messages, provided that a handler exists which produces
6331 output that can be (re)integrated into \*(UA's normal visual display.
6332 (E.g., at the time of this writing some newsletters ship their full
6333 content only in the rich HTML part, whereas the plain text part only
6334 contains topic subjects.)
6337 .It Va mime-counter-evidence
6340 field is used to decide how to handle MIME parts.
6341 Some MUAs however don't use
6343 or a similar mechanism to correctly classify content, but simply specify
6344 .Ql application/octet-stream ,
6345 even for plain text attachments like
6347 If this variable is set then \*(UA will try to classify such MIME
6348 message parts on its own, if possible, for example via a possibly
6349 existent attachment filename.
6350 A non-empty value may also be given, in which case a number is expected,
6351 actually a carrier of bits.
6352 Creating the bit-carrying number is a simple addition:
6353 .Bd -literal -offset indent
6354 ? !echo Value should be set to $((2 + 4 + 8))
6355 Value should be set to 14
6358 .Bl -bullet -compact
6360 If bit two is set (2) then the detected
6362 content-type will be carried along with the message and be used for
6364 .Va pipe-TYPE/SUBTYPE
6365 is responsible for the MIME part, shall that question arise;
6366 when displaying such a MIME part the part-info will indicate the
6367 overridden content-type by showing a plus-sign
6370 If bit three is set (4) then the counter-evidence is always produced
6371 and a positive result will be used as the MIME type, even forcefully
6372 overriding the parts given MIME type.
6374 If bit four is set (8) then as a last resort the actual content of
6375 .Ql application/octet-stream
6376 parts will be inspected, so that data which looks like plain text can be
6381 .It Va mimetypes-load-control
6382 This option can be used to control which of the
6384 databases are loaded by \*(UA, as furtherly described in the section
6385 .Sx "The mime.types files" .
6388 is part of the option value, then the user's personal
6390 file will be loaded (if it exists); likewise the letter
6392 controls loading of the system wide
6393 .Pa /etc/mime.types ;
6394 directives found in the user file take precedence, letter matching is
6396 If this option is not set \*(UA will try to load both files.
6397 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6398 but they will be matched last.
6400 More sources can be specified by using a different syntax: if the
6401 value string contains an equals sign
6403 then it is instead parsed as a comma-separated list of the described
6406 pairs; the given filenames will be expanded and loaded, and their
6407 content may use the extended syntax that is described in the section
6408 .Sx "The mime.types files" .
6409 Directives found in such files always take precedence (are prepended to
6410 the MIME type cache).
6413 .It Va NAIL_EXTRA_RC
6414 The name of an optional startup file to be read last.
6415 This variable has an effect only if it is set in any of the
6416 .Sx "Resource files" ,
6417 it is not imported from the environment.
6418 Use this file for commands that are not understood by other POSIX
6423 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6424 \*(BO\*(IN\*(OP Used to control usage of the users
6426 file for lookup of account credentials, as documented in the section
6427 .Sx "On URL syntax and credential lookup"
6431 .Sx "The .netrc file"
6432 documents the file format.
6436 If this variable has the value
6438 newly created local folders will be in Maildir format.
6442 Checks for new mail in the current folder each time the prompt is shown.
6443 A Maildir folder must be re-scanned to determine if new mail has arrived.
6444 If this variable is set to the special value
6446 then a Maildir folder will not be rescanned completely, but only
6447 timestamp changes are detected.
6451 .It Va on-compose-enter , on-compose-leave
6452 \*(ID Macro hooks which will be executed before compose mode is
6453 entered, and after composing has been finished, respectively.
6454 Please note that this interface is very likely to change in v15, and
6455 should therefore possibly even be seen as experimental.
6457 are by default enabled for these hooks, causing any setting to be
6458 forgotten after the message has been sent.
6459 The following variables will be set temporarily during execution of the
6462 .Bl -tag -compact -width ".It Va compose_subject"
6465 .It Va compose-sender
6467 .It Va compose-to , compose-cc , compose-bcc
6468 The list of receiver addresses as a space-separated list.
6469 .It Va compose-subject
6475 \*(BO Causes the filename given in the
6478 and the sender-based filenames for the
6482 commands to be interpreted relative to the directory given in the
6484 variable rather than to the current directory,
6485 unless it is set to an absolute pathname.
6489 \*(BO If set, each message feed through the command given for
6491 is followed by a formfeed character
6495 .It Va password-USER@HOST , password-HOST , password
6496 \*(IN Variable chain that sets a password, which is used in case none has
6497 been given in the protocol and account-specific URL;
6498 as a last resort \*(UA will ask for a password on the user's terminal if
6499 the authentication method requires a password.
6500 Specifying passwords in a startup file is generally a security risk;
6501 the file should be readable by the invoking user only.
6503 .It Va password-USER@HOST
6504 \*(OU (see the chain above for \*(IN)
6505 Set the password for
6509 If no such variable is defined for a host,
6510 the user will be asked for a password on standard input.
6511 Specifying passwords in a startup file is generally a security risk;
6512 the file should be readable by the invoking user only.
6516 \*(BO Send messages to the
6518 command without performing MIME and character set conversions.
6522 .It Va pipe-TYPE/SUBTYPE
6523 When a MIME message part of type
6525 (case-insensitive) is displayed or quoted,
6526 its text is filtered through the value of this variable interpreted as
6530 forces interpretation of the message part as plain text, e.g.,
6531 .Ql set pipe-application/xml=@
6532 will henceforth display XML
6534 (The same could also be achieved by adding a MIME type marker with the
6537 And \*(OPally MIME type handlers may be defined via
6538 .Sx "The Mailcap files"
6539 \(em corresponding flag strings are shown in parenthesis below.)
6544 can in fact be used to adjust usage and behaviour of a following shell
6545 command specification by appending trigger characters to it, e.g., the
6546 following hypothetical command specification could be used:
6547 .Bd -literal -offset indent
6548 set pipe-X/Y="@*!++=@vim ${NAIL_FILENAME_TEMPORARY}"
6552 .Bl -tag -compact -width ".It Ql __"
6554 Simply by using the special
6556 prefix the MIME type (shell command) handler will only be invoked to
6557 display or convert the MIME part if the message is addressed directly
6558 and alone by itself.
6559 Use this trigger to disable this and always invoke the handler
6560 .Pf ( Cd x-mailx-always ) .
6563 If set the handler will not be invoked when a message is to be quoted,
6564 but only when it will be displayed
6565 .Pf ( Cd x-mailx-noquote ) .
6568 The command will be run asynchronously, i.e., without blocking \*(UA,
6569 which may be a handy way to display a, e.g., PDF file while also
6570 continuing to read the mail message
6571 .Pf ( Cd x-mailx-async ) .
6572 Asynchronous execution implies
6576 The command must be run on an interactive terminal, \*(UA will
6577 temporarily release the terminal to it
6578 .Pf ( Cd needsterminal ) .
6579 This flag is mutual exclusive with
6581 will only be used in interactive mode and implies
6585 Request creation of a zero-sized temporary file, the absolute pathname
6586 of which will be made accessable via the environment variable
6587 .Ev NAIL_FILENAME_TEMPORARY
6588 .Pf ( Cd x-mailx-tmpfile ) .
6589 If this trigger is given twice then the file will be unlinked
6590 automatically by \*(UA when the command loop is entered again at latest
6591 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6592 (Don't use this for asynchronous handlers.)
6595 Normally the MIME part content is passed to the handler via standard
6596 input; if this flag is set then the data will instead be written into
6597 .Ev NAIL_FILENAME_TEMPORARY
6598 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6599 the creation of which is implied; note however that in order to cause
6600 deletion of the temporary file you still have to use two plus signs
6605 To avoid ambiguities with normal shell command content you can use
6606 another at-sign to forcefully terminate interpretation of remaining
6608 (Any character not in this list will have the same effect.)
6612 Some information about the MIME part to be displayed is embedded into
6613 the environment of the shell command:
6616 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6619 The MIME content-type of the part, if known, the empty string otherwise.
6622 .It Ev NAIL_CONTENT_EVIDENCE
6624 .Va mime-counter-evidence
6625 includes the carry-around-bit (2), then this will be set to the detected
6626 MIME content-type; not only then identical to
6627 .Ev \&\&NAIL_CONTENT
6631 .It Ev NAIL_FILENAME
6632 The filename, if any is set, the empty string otherwise.
6635 .It Ev NAIL_FILENAME_GENERATED
6639 .It Ev NAIL_FILENAME_TEMPORARY
6640 If temporary file creation has been requested through the command prefix
6641 this variable will be set and contain the absolute pathname of the
6646 The temporary directory that \*(UA uses.
6647 Usually identical to
6649 but guaranteed to be set and usable by child processes;
6650 to ensure the latter condition for
6657 .It Va pipe-EXTENSION
6658 This is identical to
6659 .Va pipe-TYPE/SUBTYPE
6662 (normalized to lowercase using character mappings of the ASCII charset)
6663 names a file extension, e.g.,
6665 Handlers registered using this method take precedence.
6668 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6669 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6670 The only possible value as of now is
6672 which is thus the default.
6675 .Mx Va pop3-bulk-load
6676 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6677 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6678 the messages, and only requests the message bodies on user request.
6679 For the POP3 protocol this means that the message headers will be
6681 If this option is set then \*(UA will download only complete messages
6682 from the given POP3 server(s) instead.
6684 .Mx Va pop3-keepalive
6685 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6686 \*(OP POP3 servers close the connection after a period of inactivity;
6687 the standard requires this to be at least 10 minutes,
6688 but practical experience may vary.
6689 Setting this variable to a numeric value greater than
6693 command to be sent each value seconds if no other operation is performed.
6696 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6697 \*(BO\*(OP Unless this variable is set the
6699 authentication method will be used when connecting to a POP3 server that
6703 is that the password is not sent in clear text over the wire and that
6704 only a single packet is sent for the user/password tuple.
6706 .Va pop3-no-apop-HOST
6709 .Mx Va pop3-use-starttls
6710 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6711 \*(BO\*(OP Causes \*(UA to issue a
6713 command to make an unencrypted POP3 session SSL/TLS encrypted.
6714 This functionality is not supported by all servers,
6715 and is not used if the session is already encrypted by the POP3S method.
6717 .Va pop3-use-starttls-HOST
6721 .It Va print-alternatives
6722 \*(BO When a MIME message part of type
6723 .Ql multipart/alternative
6724 is displayed and it contains a subpart of type
6726 other parts are normally discarded.
6727 Setting this variable causes all subparts to be displayed,
6728 just as if the surrounding part was of type
6729 .Ql multipart/mixed .
6733 The string shown when a command is accepted.
6734 Prompting may be prevented by setting this to the null string
6736 .Pf no Va prompt ) .
6737 If a value is assigned the following \*(UA specific additional sequences
6744 is set, in which case it expands to
6748 is the default value of
6751 which will expand to
6753 if the last command failed and to
6757 which will expand to the name of the currently active
6759 if any, and to the empty string otherwise, and
6761 which will expand to the name of the currently active mailbox.
6762 (Note that the prompt buffer is size-limited, excess is cut off.)
6768 to encapsulate the expansions of the
6772 escape sequences as necessary to correctly display bidirectional text,
6773 this is not true for the final string that makes up
6775 as such, i.e., real BIDI handling is not supported.
6779 \*(BO Suppresses the printing of the version when first invoked.
6783 If set, \*(UA starts a replying message with the original message
6784 prefixed by the value of the variable
6786 Normally, a heading consisting of
6787 .Dq Fromheaderfield wrote:
6788 is put before the quotation.
6793 variable, this heading is omitted.
6796 is assigned, the headers selected by the
6797 .Ic ignore Ns / Ns Ic retain
6798 commands are put above the message body,
6801 acts like an automatic
6807 is assigned, all headers are put above the message body and all MIME
6808 parts are included, making
6810 act like an automatic
6813 .Va quote-as-attachment .
6816 .It Va quote-as-attachment
6817 \*(BO Add the original message in its entirety as a
6819 MIME attachment when replying to a message.
6820 Note this works regardless of the setting of
6825 \*(OP Can be set in addition to
6827 Setting this turns on a more fancy quotation algorithm in that leading
6828 quotation characters are compressed and overlong lines are folded.
6830 can be set to either one or two (space separated) numeric values,
6831 which are interpreted as the maximum (goal) and the minimum line length,
6832 respectively, in a spirit rather equal to the
6834 program, but line-, not paragraph-based.
6835 If not set explicitly the minimum will reflect the goal algorithmically.
6836 The goal can't be smaller than the length of
6838 plus some additional pad.
6839 Necessary adjustments take place silently.
6842 .It Va recipients-in-cc
6843 \*(BO On group replies, specify only the sender of the original mail in
6845 and mention the other recipients in the secondary
6847 By default all recipients of the original mail will be addressed via
6852 If defined, gives the pathname of the folder used to record all outgoing
6854 If not defined, then outgoing mail is not saved.
6855 When saving to this folder fails the message is not sent,
6856 but instead saved to
6860 .It Va record-resent
6861 \*(BO If both this variable and the
6868 commands save messages to the
6870 folder as it is normally only done for newly composed messages.
6873 .It Va reply-in-same-charset
6874 \*(BO If this variable is set \*(UA first tries to use the same
6875 character set of the original message for replies.
6876 If this fails, the mechanism described in
6877 .Sx "Character sets"
6878 is evaluated as usual.
6881 .It Va reply_strings
6882 Can be set to a comma-separated list of (case-insensitive according to
6883 ASCII rules) strings which shall be recognized in addition to the
6886 reply message indicators \(en builtin are
6888 which is mandated by RFC 5322, as well as the german
6893 A list of addresses to put into the
6895 field of the message header.
6896 Members of this list are handled as if they were in the
6901 .It Va reply-to-honour
6904 header is honoured when replying to a message via
6908 This is a quadoption; if set without a value it defaults to
6912 .It Va rfc822-body-from_
6913 \*(BO This variable can be used to force displaying a so-called
6915 line for messages that are embedded into an envelope mail via the
6917 MIME mechanism, for more visual convenience.
6921 \*(BO Enable saving of (partial) messages in
6923 upon interrupt or delivery error.
6927 When \*(UA initially displays the message headers it determines the
6928 number to display by looking at the speed of the terminal.
6929 The faster the terminal, the more will be shown.
6930 This option specifies the number to use and overrides the calculation.
6931 This number is also used for scrolling with the
6934 Overall screen dimensions and pager usage is influenced by the
6935 environment variables
6943 .It Va searchheaders
6944 \*(BO Expand message-list specifiers in the form
6946 to all messages containing the substring
6950 The string search is case insensitive.
6954 \*(OP A comma-separated list of character set names that can be used in
6955 outgoing internet mail.
6956 The value of the variable
6958 is automatically appended to this list of character-sets.
6959 If no character set conversion capabilities are compiled into \*(UA then
6960 the only supported charset is
6963 .Va sendcharsets-else-ttycharset
6964 and refer to the section
6965 .Sx "Character sets"
6966 for the complete picture of character set conversion in \*(UA.
6969 .It Va sendcharsets-else-ttycharset
6970 \*(BO\*(OP If this variable is set, but
6972 is not, then \*(UA acts as if
6974 had been set to the value of the variable
6976 In effect this combination passes through the message data in the
6977 character set of the current locale (given that
6979 hasn't been set manually), i.e., without converting it to the
6981 fallback character set.
6982 Thus, mail message text will be in ISO-8859-1 encoding when send from
6983 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
6985 If no character set conversion capabilities are available in \*(UA then
6986 the only supported character set is
6991 An address that is put into the
6993 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6994 responsible for the actual transmission of the message.
6995 This field should normally not be used unless the
6997 field contains more than one address, on which case it is required.
7000 address is handled as if it were in the
7006 To use an alternate mail transport agent (MTA),
7007 set this option to the full pathname of the program to use.
7008 It may be necessary to set
7009 .Va sendmail-progname
7012 The MTA will be passed command line arguments from several possible
7013 sources: from the variable
7014 .Va sendmail-arguments
7015 if set, from the command line if given and the variable
7018 Argument processing of the MTA will be terminated with a
7022 The otherwise occurring implicit usage of the following MTA command line
7023 arguments can be disabled by setting the boolean option
7024 .Va sendmail-no-default-arguments
7025 (which will also disable passing
7029 (for not treating a line with only a dot
7031 character as the end of input),
7039 option is set); in conjunction with the
7041 command line option \*(UA will also pass
7047 .It Va sendmail-arguments
7048 Arguments to pass through to the Mail-Transfer-Agent can be given via
7050 The content of this variable will be split up in a vector of arguments
7051 which will be joined onto other possible MTA options:
7053 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7056 .It Va sendmail-no-default-arguments
7057 \*(BO Unless this option is set \*(UA will pass some well known
7058 standard command line options to the defined
7060 program, see there for more.
7063 .It Va sendmail-progname
7064 Many systems use a so-called
7066 environment to ensure compatibility with
7068 This works by inspecting the name that was used to invoke the mail
7070 If this variable is set then the mailwrapper (the program that is
7071 actually executed when calling
7073 will treat its contents as that name.
7079 \*(BO When sending a message wait until the MTA (including the builtin
7080 SMTP one) exits before accepting further commands.
7082 with this variable set errors reported by the MTA will be recognizable!
7083 If the MTA returns a non-zero exit status,
7084 the exit status of \*(UA will also be non-zero.
7088 \*(BO Setting this option causes \*(UA to start at the last message
7089 instead of the first one when opening a mail folder.
7093 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7094 address in the header field summary and in message specifications.
7098 \*(BO Causes the recipient of the message to be shown in the header
7099 summary if the message was sent by the user.
7103 A string for use with the
7109 A string for use with the
7115 Must correspond to the name of a readable file if set.
7116 The file's content is then appended to each singlepart message
7117 and to the first part of each multipart message.
7118 Be warned that there is no possibility to edit the signature for an
7122 .It Va skipemptybody
7123 \*(BO If an outgoing message does not contain any text in its first or
7124 only message part, do not send it but discard it silently (see also the
7130 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7131 Enhanced Mail) format for verification of S/MIME signed messages.
7134 .It Va smime-ca-file
7135 \*(OP Specifies a file with CA certificates in PEM format for
7136 verification of S/MIME signed messages.
7139 .It Va smime-cipher-USER@HOST , smime-cipher
7140 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7141 messages (for the specified account).
7142 RFC 5751 mandates a default of
7145 Possible values are (case-insensitive and) in decreasing cipher strength:
7153 (DES EDE3 CBC, 168 bits; default if
7155 isn't available) and
7159 The actually available cipher algorithms depend on the cryptographic
7160 library that \*(UA uses.
7161 \*(OP Support for more cipher algorithms may be available through
7162 dynamic loading via, e.g.,
7163 .Xr EVP_get_cipherbyname 3
7164 (OpenSSL) if \*(UA has been compiled to support this.
7167 .It Va smime-crl-dir
7168 \*(OP Specifies a directory that contains files with CRLs in PEM format
7169 to use when verifying S/MIME messages.
7172 .It Va smime-crl-file
7173 \*(OP Specifies a file that contains a CRL in PEM format to use when
7174 verifying S/MIME messages.
7177 .It Va smime-encrypt-USER@HOST
7178 \*(OP If this variable is set, messages send to the given receiver are
7179 encrypted before sending.
7180 The value of the variable must be set to the name of a file that
7181 contains a certificate in PEM format.
7183 If a message is sent to multiple recipients,
7184 each of them for whom a corresponding variable is set will receive an
7185 individually encrypted message;
7186 other recipients will continue to receive the message in plain text
7188 .Va smime-force-encryption
7190 It is recommended to sign encrypted messages, i.e., to also set the
7195 .It Va smime-force-encryption
7196 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7199 .It Va smime-no-default-ca
7200 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7205 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7206 and include the user's certificate as a MIME attachment.
7207 Signing a message enables a recipient to verify that the sender used
7208 a valid certificate,
7209 that the email addresses in the certificate match those in the message
7210 header and that the message content has not been altered.
7211 It does not change the message text,
7212 and people will be able to read the message as usual.
7214 .Va smime-sign-cert , smime-sign-include-certs
7216 .Va smime-sign-message-digest .
7218 .Mx Va smime-sign-cert
7219 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7220 \*(OP Points to a file in PEM format.
7221 For the purpose of signing and decryption this file needs to contain the
7222 user's private key as well as his certificate.
7226 is always derived from the value of
7228 (or, if that contains multiple addresses,
7230 For the purpose of encryption the recipient's public encryption key
7231 (certificate) is expected; the command
7233 can be used to save certificates of signed messages (the section
7234 .Sx "Signed and encrypted messages with S/MIME"
7235 gives some details).
7236 This mode of operation is usually driven by the specialized form.
7238 When decrypting messages the account is derived from the recipient
7243 of the message, which are searched for addresses for which such
7245 \*(UA always uses the first address that matches,
7246 so if the same message is sent to more than one of the user's addresses
7247 using different encryption keys, decryption might fail.
7249 .Mx Va smime-sign-include-certs
7250 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7251 \*(OP If used, this is supposed to a consist of a comma-separated list
7252 of files, each of which containing a single certificate in PEM format to
7253 be included in the S/MIME message in addition to the
7256 This is most useful for long certificate chains if it is desired to aid
7257 the receiving party's verification process.
7258 Note that top level certificates may also be included in the chain but
7259 don't play a role for verification.
7261 .Va smime-sign-cert .
7262 Remember that for this
7264 refers to the variable
7266 (or, if that contains multiple addresses,
7269 .Mx Va smime-sign-message-digest
7270 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7271 \*(OP Specifies the message digest to use when signing S/MIME messages.
7272 RFC 5751 mandates a default of
7274 Possible values are (case-insensitive and) in decreasing cipher strength:
7282 The actually available message digest algorithms depend on the
7283 cryptographic library that \*(UA uses.
7284 \*(OP Support for more message digest algorithms may be available
7285 through dynamic loading via, e.g.,
7286 .Xr EVP_get_digestbyname 3
7287 (OpenSSL) if \*(UA has been compiled to support this.
7288 Remember that for this
7290 refers to the variable
7292 (or, if that contains multiple addresses,
7298 \*(OP Normally \*(UA invokes the program defined via
7300 to transfer messages, as described in
7301 .Sx "On sending mail, and non-interactive mode" .
7304 variable will instead cause SMTP network connections be made to the
7305 server specified therein in order to directly submit the message.
7306 \*(UA knows about three different
7307 .Dq SMTP protocols :
7309 .Bl -bullet -compact
7311 The plain SMTP protocol (RFC 5321) that normally lives on the
7312 server port 25 and requires setting the
7313 .Va smtp-use-starttls
7314 variable to enter a SSL/TLS encrypted session state.
7315 Assign a value like \*(IN
7316 .Ql [smtp://][user[:password]@]server[:port]
7318 .Ql [smtp://]server[:port] )
7319 to choose this protocol.
7321 Then the so-called SMTPS which is supposed to live on server port 465
7322 and is automatically SSL/TLS secured.
7323 Unfortunately it never became a standardized protocol and may thus not
7324 be supported by your hosts network service database
7325 \(en in fact the port number has already been reassigned to other
7328 SMTPS is nonetheless a commonly offered protocol and thus can be
7329 chosen by assigning a value like \*(IN
7330 .Ql smtps://[user[:password]@]server[:port]
7332 .Ql smtps://server[:port] ) ;
7333 due to the mentioned problems it is usually necessary to explicitly
7338 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7339 lives on server port 587 and is practically identically to the SMTP
7340 protocol from \*(UA's point of view beside that; it requires setting the
7341 .Va smtp-use-starttls
7342 variable to enter a SSL/TLS secured session state.
7343 Assign a value like \*(IN
7344 .Ql submission://[user[:password]@]server[:port]
7346 .Ql submission://server[:port] ) .
7349 For more on credentials etc. please see
7350 .Sx "On URL syntax and credential lookup" .
7351 The SMTP transfer is executed in a child process, which runs
7352 asynchronously unless either the
7357 If it receives a TERM signal, it will abort and save the message to
7362 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7363 \*(OP Variable chain that sets the SMTP authentication method.
7370 as well as the \*(OPal methods
7376 method doesn't need any user credentials,
7378 requires a user name and all other methods require a user name and
7386 .Va smtp-auth-password
7388 .Va smtp-auth-user ) .
7393 .Va smtp-auth-USER@HOST :
7394 may override dependend on sender address in the variable
7397 .It Va smtp-auth-password
7398 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7399 If the authentication method requires a password, but neither
7400 .Va smtp-auth-password
7402 .Va smtp-auth-password-USER@HOST
7404 \*(UA will ask for a password on the user's terminal.
7406 .It Va smtp-auth-password-USER@HOST
7408 .Va smtp-auth-password
7409 for specific values of sender addresses, dependent upon the variable
7412 .It Va smtp-auth-user
7413 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7414 If the authentication method requires a user name, but neither
7417 .Va smtp-auth-user-USER@HOST
7419 \*(UA will ask for a user name on the user's terminal.
7421 .It Va smtp-auth-user-USER@HOST
7424 for specific values of sender addresses, dependent upon the variable
7428 .It Va smtp-hostname
7429 \*(IN Normally \*(UA uses the variable
7431 to derive the necessary
7433 information to issue a
7438 can be used to use the
7440 from the SMTP account
7447 from the content of this variable (or, if that is the empty string,
7449 or the local hostname as a last resort).
7450 This often allows using an address that is itself valid but hosted by
7451 a provider other than which (in
7453 is about to send the message.
7454 Setting this variable also influences the generated
7457 .Mx Va smtp-use-starttls
7458 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7459 \*(BO\*(OP Causes \*(UA to issue a
7461 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7462 transport layer security.
7466 .It Va spam-interface
7467 \*(OP In order to use any of the spam-related commands (like, e.g.,
7469 the desired spam interface must be defined by setting this variable.
7470 Please refer to the manual section
7472 for the complete picture of spam handling in \*(UA.
7473 All or none of the following interfaces may be available:
7475 .Bl -tag -width ".It Ql _ilte_"
7481 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7483 Different to the generic filter interface \*(UA will automatically add
7484 the correct arguments for a given command and has the necessary
7485 knowledge to parse the program's output.
7488 will have been compiled into the \*(UA binary if
7493 Shall it be necessary to define a specific connection type (rather than
7494 using a configuration file for that), the variable
7496 can be used as in, e.g.,
7497 .Ql -d server.example.com -p 783 .
7498 It is also possible to specify a per-user configuration via
7500 Note that this interface doesn't inspect the
7502 flag of a message for the command
7506 \*(UA will directly communicate with the
7512 stream socket as specified in
7514 It is possible to specify a per-user configuration via
7518 generic spam filter support via freely configurable hooks.
7519 This interface is ment for programs like
7523 and requires according behaviour in respect to the hooks' exit
7524 status for at least the command
7527 meaning a message is spam,
7531 for unsure and any other return value indicating a hard error);
7532 since the hooks can include shell code snippets diverting behaviour
7533 can be intercepted as necessary.
7535 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7538 .Va spamfilter-spam ;
7541 contains examples for some programs.
7542 The process environment of the hooks will have the variables
7543 .Ev NAIL_TMPDIR , TMPDIR
7545 .Ev NAIL_FILENAME_GENERATED
7547 Note that spam score support for
7549 isn't supported unless the \*(OPtional regular expression support is
7551 .Va spamfilter-rate-scanscore
7558 \*(OP Messages that exceed this size won't be passed through to the
7560 .Va spam-interface .
7561 The default is 420000 bytes.
7564 .It Va spamc-command
7565 \*(OP The path to the
7569 .Va spam-interface .
7570 Note that the path is not expanded, but used
7572 A fallback path will have been compiled into the \*(UA binary if the
7573 executable had been found during compilation.
7576 .It Va spamc-arguments
7577 \*(OP Even though \*(UA deals with most arguments for the
7580 automatically, it may at least sometimes be desirable to specifiy
7581 connection-related ones via this variable, e.g.,
7582 .Ql -d server.example.com -p 783 .
7586 \*(OP Specify a username for per-user configuration files for the
7588 .Va spam-interface .
7589 If this is set to the empty string then \*(UA will use the name of the
7595 \*(OP Specify the path of the
7597 domain socket on which
7599 listens for connections for the
7601 .Va spam-interface .
7602 Note that the path is not expanded, but used
7607 \*(OP Specify a username for per-user configuration files for the
7609 .Va spam-interface .
7610 If this is set to the empty string then \*(UA will use the name of the
7619 .It Va spamfilter-ham , spamfilter-noham , \
7620 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7621 \*(OP Command and argument hooks for the
7623 .Va spam-interface .
7626 contains examples for some programs.
7629 .It Va spamfilter-rate-scanscore
7630 \*(OP Because of the generic nature of the
7633 spam scores are not supported for it by default, but if the \*(OPtional
7634 regular expression support is available then setting this variable can
7635 be used to overcome this restriction.
7636 It is interpreted as follows: first a number (digits) is parsed that
7637 must be followed by a semicolon
7639 and an extended regular expression.
7640 Then the latter is used to parse the first output line of the
7642 hook, and, in case the evaluation is successful, the group that has been
7643 specified via the number is interpreted as a floating point scan score.
7647 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7648 Enhanced Mail) for verification of of SSL/TLS server certificates.
7650 .Xr SSL_CTX_load_verify_locations 3
7651 for more information.
7655 \*(OP Specifies a file with CA certificates in PEM format for
7656 verification of SSL/TLS server certificates.
7658 .Xr SSL_CTX_load_verify_locations 3
7659 for more information.
7662 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7663 \*(OP Variable chain that sets the file name for a SSL/TLS client
7664 certificate required by some servers.
7665 This is a direct interface to the
7669 function of the OpenSSL library, if available.
7671 .Mx Va ssl-cipher-list
7672 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7673 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7674 This is a direct interface to the
7678 function of the OpenSSL library, if available; see
7680 for more information.
7681 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7683 specific cipher (protocol standards ship with a list of acceptable
7684 ciphers), possibly cramped to what the actually used SSL/TLS library
7685 supports \(en the manual section
7686 .Sx "An example configuration"
7687 also contains a SSL/TLS use case.
7690 .It Va ssl-config-file
7691 \*(OP If this variable is set \*(UA will call
7692 .Xr CONF_modules_load_file 3
7693 to allow OpenSSL to be configured according to the host system wide
7695 If a non-empty value is given then this will be used to specify the
7696 configuration file to be used instead of the global OpenSSL default;
7697 note that in this case it is an error if the file cannot be loaded.
7698 The application name will always be passed as
7703 \*(OP Specifies a file that contains a CRL in PEM format to use when
7704 verifying SSL/TLS server certificates.
7708 \*(OP Specifies a directory that contains files with CRLs in PEM format
7709 to use when verifying SSL/TLS server certificates.
7712 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7713 \*(OP Variable chain that sets the file name for the private key of
7714 a SSL/TLS client certificate.
7715 If unset, the name of the certificate file is used.
7716 The file is expected to be in PEM format.
7717 This is a direct interface to the
7721 function of the OpenSSL library, if available.
7724 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7726 \*(OB Please use the newer and more flexible
7728 instead: if both values are set,
7730 will take precedence!
7731 Can be set to the following values, the actually used
7733 specification to which it is mapped is shown in parenthesis:
7735 .Pf ( Ql -ALL, TLSv1.2 ) ,
7737 .Pf ( Ql -ALL, TLSv1.1 ) ,
7739 .Pf ( Ql -ALL, TLSv1 )
7742 .Pf ( Ql -ALL, SSLv3 ) ;
7747 and thus includes the SSLv3 protocol.
7748 Note that SSLv2 is no longer supported at all.
7751 .It Va ssl-no-default-ca
7752 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7756 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7757 \*(OP Specify the used SSL/TLS protocol.
7758 This is a direct interface to the
7762 function of the OpenSSL library, if available;
7763 otherwise an \*(UA internal parser is used which understands the
7764 following subset of (case-insensitive) command strings:
7770 as well as the special value
7772 Multiple specifications may be given via a comma-separated list which
7773 ignores any whitespace.
7776 plus prefix will enable a protocol, a
7778 minus prefix will disable it, so that
7780 will enable only the TLSv1.2 protocol.
7782 It depends upon the used TLS/SSL library which protocols are actually
7783 supported and which protocols are used if
7785 is not set, but note that SSLv2 is no longer supported at all and
7787 Especially for older protocols explicitly securing
7789 may be worthwile, see
7790 .Sx "An example configuration" .
7794 \*(OP Gives the pathname to an entropy daemon socket, see
7796 Not all SSL/TLS libraries support this.
7799 .It Va ssl-rand-file
7800 \*(OP Gives the filename to a file with random entropy data, see
7801 .Xr RAND_load_file 3 .
7802 If this variable is not set, or set to the empty string, or if the
7803 filename expansion failed, then
7804 .Xr RAND_file_name 3
7805 will be used to create the filename if, and only if,
7807 documents that the SSL PRNG is not yet sufficiently seeded.
7808 If \*(UA successfully seeded the SSL PRNG then it'll update the file via
7809 .Xr RAND_write_file 3 .
7810 This variable is only used if
7812 is not set (or not supported by the SSL/TLS library).
7815 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7816 \*(OP Variable chain that sets the action to be performed if an error
7817 occurs during SSL/TLS server certificate validation.
7818 Valid (case-insensitive) values are
7820 (fail and close connection immediately),
7822 (ask whether to continue on standard input),
7824 (show a warning and continue),
7826 (do not perform validation).
7832 If only set without an assigned value, then this option inhibits the
7837 header fields that include obvious references to \*(UA.
7838 There are two pitfalls associated with this:
7839 First, the message id of outgoing messages is not known anymore.
7840 Second, an expert may still use the remaining information in the header
7841 to track down the originating mail user agent.
7846 suppression doesn't occur.
7851 (\*(OP) This specifies a comma-separated list of
7856 .Sx "On terminal control and line editor" ,
7857 escape commas with backslash) to be used to overwrite or define entries.
7859 that this variable will only be queried once at program startup and can
7860 thus only be specified in resource files or on the command line.
7863 String capabilities form
7865 pairs and are expected unless noted otherwise.
7866 Numerics have to be notated as
7868 where the number is expected in normal decimal notation.
7869 Finally, booleans don't have any value but indicate a true or false
7870 state simply by being defined or not; this indeed means that \*(UA
7871 doesn't support undefining a boolean that normally exists.
7872 The following example defines that the terminal has 256 colours:
7874 .Bd -literal -offset indent
7875 set termcap="colors=256"
7879 Keycodes can easily be detected with the command
7881 by running it on an interactive terminal via
7885 command line option if available) and pressing some keys: here
7893 (actually a visualized numeric where
7895 stands for 1 etc.; in fact: the numeric value of
7897 in the US-ASCII character set bitwise XORd with
7900 .Ql $ echo $((0x41 ^ 0x40)) .
7903 and other control characters have to be notated as shell-style
7904 escape sequences, e.g.,
7914 The following terminal capabilities are or may be meaningful for the
7915 operation of the builtin line editor or \*(UA in general:
7918 .Bl -tag -compact -width yay
7920 .It Cd colors Ns \0or Cd Co
7922 numeric capability specifying the maximum number of colours.
7923 Note that \*(UA doesn't actually care about the terminal beside that,
7924 but always emits ANSI/ISO 6429 escape sequences for producing the
7925 colour and font attributes.
7928 .It Cd rmcup Ns \0or Cd te Ns \0/ Cd smcup Ns \0or Cd ti
7932 respectively: exit and enter the alternative screen
7934 effectively turning \*(UA into a fullscreen application.
7935 To disable that, set (at least) one to the empty string.
7937 .It Cd smkx Ns \0or Cd ks Ns \0/ Cd rmkx Ns \0or Cd ke
7941 respectively: enable and disable the keypad.
7942 This is always enabled if available, because it seems even keyboards
7943 without keypads generate other key codes for, e.g., cursor keys in that
7944 case, and only if enabled we see the codes that we are interested in.
7946 .It Cd ed Ns \0or Cd cd
7950 .It Cd clear Ns \0or Cd cl
7952 clear the screen and home cursor.
7953 (Will be simulated via
7958 .It Cd home Ns \0or Cd ho
7963 .It Cd el Ns \0or Cd ce
7965 clear to the end of line.
7966 (Will be simulated via
7968 plus repititions of space characters.)
7970 .It Cd hpa Ns \0or Cd ch
7971 .Cd column_address :
7972 move the cursor (to the given column parameter) in the current row.
7973 (Will be simulated via
7979 .Cd carriage_return :
7980 move to the first column in the current row.
7981 The default builtin fallback is
7984 .It Cd cub1 Ns \0or Cd le
7986 move the cursor left one space (non-destructively).
7987 The default builtin fallback is
7990 .It Cd cuf1 Ns \0or Cd nd
7992 move the cursor right one space (non-destructively).
7993 The default builtin fallback is
7995 which is used by most terminals.
8004 .It Va termcap-disable
8005 \*(OP Disable any interaction with a terminal control library.
8006 If set only some generic fallback builtins and possibly the content of
8008 describe the terminal to \*(UA.
8010 that this variable will only be queried once at program startup and can
8011 thus only be specified in resource files or on the command line.
8015 If defined, gives the number of lines of a message to be displayed
8018 normally, the first five lines are printed.
8022 The character set of the terminal \*(UA operates on,
8023 and the one and only supported character set that \*(UA can use if no
8024 character set conversion capabilities have been compiled into it,
8025 in which case it defaults to ISO-8859-1 unless it can deduce a value
8029 Refer to the section
8030 .Sx "Character sets"
8031 for the complete picture about character sets.
8034 .It Va user-HOST , user
8035 \*(IN Variable chain that sets a global fallback user name, which is
8036 used in case none has been given in the protocol and account-specific
8038 This variable defaults to the value of the first of
8042 that is set (the former being SystemV and POSIX standard, the latter BSD).
8046 \*(BO Setting this option enables upward compatibility with \*(UA
8047 version 15.0 in respect to which configuration options are available and
8048 how they are handled.
8049 This manual uses \*(IN and \*(OU to refer to the new and the old way of
8050 doing things, respectively.
8054 \*(BO Setting this option, also controllable via the command line option
8056 causes \*(UA to be more verbose, e.g., it will display obsoletion
8057 warnings and SSL/TLS certificate chains.
8058 Even though marked \*(BO this option may be set twice in order to
8059 increase the level of verbosity even more, in which case even details of
8060 the actual message delivery and protocol conversations are shown.
8063 is sufficient to disable verbosity as such.
8069 .It Va version , version-major , version-minor , version-update
8070 \*(RO \*(UA version information: the first variable contains a string
8071 containing the complete version identification \(en this is identical to
8072 the output of the command
8074 The latter three contain only digits: the major, minor and update
8078 .It Va writebackedited
8079 If this variable is set messages modified using the
8083 commands are written back to the current folder when it is quit;
8084 it is only honoured for writable folders in MBOX format, though.
8085 Note that the editor will be pointed to the raw message content in that
8086 case, i.e., neither MIME decoding nor decryption will have been
8087 performed, and proper RFC 4155
8089 quoting of newly added or edited content is also left as an excercise to
8093 .\" }}} (INTERNAL VARIABLES)
8096 .\" .Sh ENVIRONMENT {{{
8100 .Dq environment variable
8101 should be considered an indication that the following variables are
8102 either standardized as being vivid parts of process environments, or
8103 are commonly found in there.
8104 The process environment is inherited from the
8106 once \*(UA is started, and unless otherwise explicitly noted variables
8107 in there integrate into the normal handling of
8108 .Sx "INTERNAL VARIABLES" ,
8109 from \*(UA's point of view, i.e., they can be
8111 as such in resource files and need not necessarily come from the process
8112 environment and be managed via
8116 E.g., the following example, applicable to a POSIX shell, sets the
8118 environment variable for \*(UA only, and beforehand exports the
8120 in order to affect any further processing in the running shell:
8122 .Bd -literal -offset indent
8123 $ EDITOR="vim -u ${HOME}/.vimrc"
8125 $ COLUMNS=80 \*(uA -R
8128 .Bl -tag -width ".It Ev _AILR_"
8131 The user's preferred width in column positions for the terminal screen
8133 Queried and used once on program startup, actively managed for child
8134 processes in interactive mode.
8138 The name of the file to use for saving aborted messages if
8140 is set; this defaults to
8148 Pathname of the text editor to use in the
8152 .Sx "TILDE ESCAPES" .
8153 A default editor is used if this value is not defined.
8157 The user's home directory.
8158 This variable is only used when it resides in the process environment.
8161 to update the value at runtime.
8168 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
8172 .Sx "Character sets" .
8176 The user's preferred number of lines on a page or the vertical screen
8177 or window size in lines.
8178 Queried and used once on program startup, actively managed for child
8179 processes in interactive mode.
8183 Pathname of the directory lister to use in the
8185 command when operating on local mailboxes.
8188 (path search through
8193 Force identification as the given user, i.e., identical to the
8195 command line option.
8196 This variable is standardized and therefore used in preference to the
8199 it is only used when it resides in the process environment.
8200 \*(ID The variable can be updated at runtime via
8202 but without having an effect on \*(UA itself.
8206 Is used as the user's mailbox, if set.
8207 Otherwise, a system-dependent default is used.
8208 Supports a logical subset of the special conventions that are documented
8217 \*(OP Overrides the default path search for
8218 .Sx "The Mailcap files" ,
8219 which is defined in the standard RFC 1524 as
8220 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
8221 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8222 (\*(UA makes it a configuration option, however.)
8223 Note this is not a search path, but a path search.
8227 Is used as a startup file instead of
8230 When \*(UA scripts are invoked on behalf of other users,
8231 either this variable should be set to
8235 command line option should be used in order to avoid side-effects from
8236 reading their configuration files.
8237 This variable is only used when it resides in the process environment.
8241 The name of the user's mbox file.
8242 A logical subset of the special conventions that are documented for the
8247 The fallback default is
8252 Traditionally this secondary mailbox is used as the file to save
8253 messages from the system mailbox that have been read.
8255 .Sx "Message states" .
8258 .It Ev NAIL_NO_SYSTEM_RC
8259 If this variable is set then reading of
8261 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8262 had been started up with the option
8264 This variable is only used when it resides in the process environment.
8268 \*(IN\*(OP This variable overrides the default location of the user's
8274 Pathname of the program to use for backing the command
8278 variable enforces usage of a pager for output.
8279 The default paginator is
8281 (path search through
8284 \*(UA inspects the contents of this variable: if its contains the string
8286 then a non-existing environment variable
8293 dependent on whether terminal control support is available and whether
8294 that supports full (alternative) screen mode or not (also see
8295 .Sx "On terminal control and line editor" ) .
8299 will optionally be set to
8306 A list of directories that is searched by the shell when looking for
8307 commands (as such only recognized in the process environment).
8311 The shell to use for the commands
8317 and when starting subprocesses.
8318 A default shell is used if this option is not defined.
8322 \*(OP The terminal type for which output is to be prepared.
8323 For extended colour and font control please refer to
8324 .Sx "Coloured display" ,
8325 and for terminal management in general to
8326 .Sx "On terminal control and line editor" .
8330 Used as directory for temporary files instead of
8333 This variable is only used when it resides in the process environment.
8336 to update the value at runtime.
8340 This variable comes from the BSD world and is only used if the POSIX
8341 standard environment variable
8343 which originates in SysV
8346 Force identification as the given user, i.e., identical to the
8348 command line option.
8349 This variable is only used when it resides in the process environment.
8350 \*(ID The variable can be updated at runtime via
8352 but without having an effect on \*(UA itself.
8356 Pathname of the text editor to use in the
8360 .Sx "TILDE ESCAPES" .
8368 .Bl -tag -width ".It Pa _etc/mime.type_"
8370 File giving initial commands.
8373 System wide initialization file.
8377 \*(OP Personal MIME type handler definition file, see
8378 .Sx "The Mailcap files" .
8379 (RFC 1524 location, the actual path is a configuration option.)
8383 \*(OP System wide MIME type handler definition file, see
8384 .Sx "The Mailcap files" .
8385 (RFC 1524 location, the actual path is a configuration option.)
8388 .It Pa ~/.mime.types
8389 Personal MIME types, see
8390 .Sx "The mime.types files" .
8393 .It Pa /etc/mime.types
8394 System wide MIME types, see
8395 .Sx "The mime.types files" .
8399 \*(IN\*(OP The default location of the users
8401 file \(en the section
8402 .Sx "The .netrc file"
8403 documents the file format.
8406 .\" .Ss "The mime.types files" {{{
8407 .Ss "The mime.types files"
8409 When sending messages \*(UA tries to determine the content type of all
8411 When displaying message content or attachments \*(UA uses the content
8412 type to decide wether it can directly display data or wether it needs to
8413 deal with content handlers.
8414 It learns about MIME types and how to treat them by reading
8416 files, the loading of which can be controlled by setting the variable
8417 .Va mimetypes-load-control .
8420 can also be used to deal with MIME types.)
8422 files have the following syntax:
8425 .Dl type/subtype extension [extension ...]
8430 are strings describing the file contents, and one or multiple
8432 s, separated by whitespace, name the part of a filename starting after
8433 the last dot (of interest).
8434 Comments may be introduced anywhere on a line with a number sign
8436 causing the remaining line to be discarded.
8438 \*(UA also supports an extended, non-portable syntax in specially
8439 crafted files, which can be loaded via the alternative value syntax of
8440 .Va mimetypes-load-control
8441 and prepends an optional
8445 .Dl [type-marker ]type/subtype extension [extension ...]
8448 The following type markers are supported:
8451 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8453 Treat message parts with this content as plain text.
8458 Treat message parts with this content as HTML tagsoup.
8459 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8460 the content as plain text instead.
8464 but instead of falling back to plain text require an explicit content
8465 handler to be defined.
8470 for sending messages:
8472 .Va mime-allow-text-controls ,
8473 .Va mimetypes-load-control .
8474 For reading etc. messages:
8475 .Sx "HTML mail and MIME attachments" ,
8476 .Sx "The Mailcap files" ,
8478 .Va mime-counter-evidence ,
8479 .Va mimetypes-load-control ,
8480 .Va pipe-TYPE/SUBTYPE ,
8481 .Va pipe-EXTENSION .
8484 .\" .Ss "The Mailcap files" {{{
8485 .Ss "The Mailcap files"
8488 .Dq User Agent Configuration Mechanism
8489 which \*(UA \*(OPally supports.
8490 It defines a file format to be used to inform mail user agent programs
8491 about the locally-installed facilities for handling various data
8492 formats, i.e., about commands and how they can be used to display, edit
8493 etc. MIME part contents, as well as a default path search that includes
8494 multiple possible locations of
8498 environment variable that can be used to overwrite that (repeating here
8499 that it is not a search path, but instead a path search specification).
8500 Any existing files will be loaded in sequence, appending any content to
8501 the list of MIME type handler directives.
8505 files consist of a set of newline separated entries.
8506 Comment lines start with a number sign
8508 (in the first column!) and are ignored.
8509 Empty lines are also ignored.
8510 All other lines form individual entries that must adhere to the syntax
8512 To extend a single entry (not comment) its line can be continued on
8513 follow lines if newline characters are
8515 by preceding them with the backslash character
8517 The standard doesn't specify how leading whitespace of follow lines is
8518 to be treated, therefore \*(UA retains it.
8522 entries consist of a number of semicolon
8524 separated fields, and the backslash
8526 character can be used to escape any following character including
8527 semicolon and itself.
8528 The first two fields are mandatory and must occur in the specified
8529 order, the remaining fields are optional and may appear in any order.
8530 Leading and trailing whitespace of content is ignored (removed).
8533 The first field defines the MIME
8535 the entry is about to handle (case-insensitively, and no backslash
8536 escaping is possible in this field).
8537 If the subtype is specified as an asterisk
8539 the entry is ment to match all subtypes of the named type, e.g.,
8541 would match any audio type.
8542 The second field defines the shell command which shall be used to
8544 MIME parts of the given type; it is implicitly called the
8551 shell commands message (MIME part) data is passed via standard input
8552 unless the given shell command includes one or more instances of the
8555 in which case these instances will be replaced with a temporary filename
8556 and the data will have been stored in the file that is being pointed to.
8559 shell commands data is assumed to be generated on standard output unless
8560 the given command includes (one ore multiple)
8562 In any case any given
8564 format is replaced with a(n already) properly quoted filename.
8565 Note that when a command makes use of a temporary file via
8567 then \*(UA will remove it again, as if the
8568 .Cd x-mailx-tmpfile ,
8569 .Cd x-mailx-tmpfile-fill
8571 .Cd x-mailx-tmpfile-unlink
8572 flags had been set; see below for more.
8575 The optional fields either define a shell command or an attribute (flag)
8576 value, the latter being a single word and the former being a keyword
8577 naming the field followed by an equals sign
8579 succeeded by a shell command, and as usual for any
8581 content any whitespace surrounding the equals sign will be removed, too.
8582 Optional fields include the following:
8585 .Bl -tag -width textualnewlines
8587 A program that can be used to compose a new body or body part in the
8594 field, but is to be used when the composing program needs to specify the
8596 header field to be applied to the composed data.
8600 A program that can be used to edit a body or body part in the given
8605 A program that can be used to print a message or body part in the given
8610 Specifies a program to be run to test some condition, e.g., the machine
8611 architecture, or the window system in use, to determine whether or not
8612 this mailcap entry applies.
8613 If the test fails, a subsequent mailcap entry should be sought; also see
8614 .Cd x-mailx-test-once .
8616 .It Cd needsterminal
8617 This flag field indicates that the given shell command must be run on
8618 an interactive terminal.
8619 \*(UA will temporarily release the terminal to the given command in
8620 interactive mode, in non-interactive mode this entry will be entirely
8621 ignored; this flag implies
8622 .Cd x-mailx-noquote .
8624 .It Cd copiousoutput
8625 A flag field which indicates that the output of the
8627 command will be an extended stream of textual output that can be
8628 (re)integrated into \*(UA's normal visual display.
8629 It is mutually exclusive with
8632 .Cd x-mailx-always .
8634 .It Cd textualnewlines
8635 A flag field which indicates that this type of data is line-oriented and
8638 all newlines should be converted to canonical form (CRLF) before
8639 encoding, and will be in that form after decoding.
8643 This field gives a file name format, in which
8645 will be replaced by a random string, the joined combination of which
8646 will be used as the filename denoted by
8647 .Ev NAIL_FILENAME_TEMPORARY .
8648 One could specify that a GIF file being passed to an image viewer should
8649 have a name ending in
8652 .Ql nametemplate=%s.gif .
8653 Note that \*(UA ignores the name template unless that solely specifies
8654 a filename suffix that consists of (ASCII) alphabetic and numeric
8655 characters, the underscore and dot only.
8658 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8659 icon to be used to visually denote the presence of this kind of data.
8660 This field is not used by \*(UA.
8663 A textual description that describes this type of data.
8665 .It Cd x-mailx-always
8666 Extension flag field that denotes that the given
8668 command shall be executed even if multiple messages will be displayed
8670 Normally messages which require external viewers that produce output
8671 which doesn't integrate into \*(UA's visual display (i.e., don't have
8673 set) have to be addressed directly and individually.
8674 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8677 .It Cd x-mailx-even-if-not-interactive
8678 An extension flag test field \(em by default handlers without
8680 are entirely ignored in non-interactive mode, but if this flag is set
8681 then their use will be considered.
8682 It is an error if this flag is set for commands that use the flag
8685 .It Cd x-mailx-noquote
8686 An extension flag field that indicates that even a
8689 command shall not be used to generate message quotes
8690 (as it would be by default).
8692 .It Cd x-mailx-async
8693 Extension flag field that denotes that the given
8695 command shall be executed asynchronously, without blocking \*(UA.
8696 Cannot be used in conjunction with
8699 .It Cd x-mailx-test-once
8700 Extension flag which denotes wether the given
8702 command shall be evaluated once only and the (boolean) result be cached.
8703 This is handy if some global unchanging condition is to be queried, like
8704 .Dq running under the X Window System .
8706 .It Cd x-mailx-tmpfile
8707 Extension flag field that requests creation of a zero-sized temporary
8708 file, the name of which is to be placed in the environment variable
8709 .Ev NAIL_FILENAME_TEMPORARY .
8710 It is an error to use this flag with commands that include a
8714 .It Cd x-mailx-tmpfile-fill
8715 Normally the MIME part content is passed to the handler via standard
8716 input; if this flag is set then the data will instead be written into
8718 .Cd x-mailx-tmpfile .
8719 In order to cause deletion of the temporary file you will have to set
8720 .Cd x-mailx-tmpfile-unlink
8722 It is an error to use this flag with commands that include a
8726 .It Cd x-mailx-tmpfile-unlink
8727 Extension flag field that requests that the temporary file shall be
8728 deleted automatically when the command loop is entered again at latest.
8729 (Don't use this for asynchronous handlers.)
8730 It is an error to use this flag with commands that include a
8732 format, or without also setting
8735 .Cd x-mailx-tmpfile-fill .
8737 .It Cd x-mailx-tmpfile-keep
8740 implies the three tmpfile related flags above, but if you want, e.g.,
8742 and deal with the temporary file yourself, you can add in this flag to
8744 .Cd x-mailx-tmpfile-unlink .
8749 The standard includes the possibility to define any number of additional
8750 entry fields, prefixed by
8752 Flag fields apply to the entire
8754 entry \(em in some unusual cases, this may not be desirable, but
8755 differentiation can be accomplished via separate entries, taking
8756 advantage of the fact that subsequent entries are searched if an earlier
8757 one does not provide enough information.
8760 command needs to specify the
8764 command shall not, the following will help out the latter (with enabled
8768 level \*(UA will show informations about handler evaluation):
8770 .Bd -literal -offset indent
8771 application/postscript; ps-to-terminal %s; needsterminal
8772 application/postscript; ps-to-terminal %s; compose=idraw %s
8776 In fields any occurrence of the format string
8778 will be replaced by the
8781 Named parameters from the
8783 field may be placed in the command execution line using
8785 followed by the parameter name and a closing
8788 The entire parameter should appear as a single command line argument,
8789 regardless of embedded spaces; thus:
8791 .Bd -literal -offset indent
8793 Content-type: multipart/mixed; boundary=42
8796 multipart/*; /usr/local/bin/showmulti \e
8797 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8799 # Executed shell command
8800 /usr/local/bin/showmulti multipart/mixed 42
8804 .\" TODO v15: Mailcap: %n,%F
8805 Note that \*(UA doesn't support handlers for multipart MIME parts as
8806 shown in this example (as of today).
8807 \*(UA doesn't support the additional formats
8811 An example file, also showing how to properly deal with the expansion of
8813 which includes any quotes that are necessary to make it a valid shell
8814 argument by itself and thus will cause undesired behaviour when placed
8815 in additional user-provided quotes:
8817 .Bd -literal -offset indent
8819 text/richtext; richtext %s; copiousoutput
8821 text/x-perl; perl -cWT %s
8825 trap "rm -f ${infile}" EXIT\e; \e
8826 trap "exit 75" INT QUIT TERM\e; \e
8828 x-mailx-async; x-mailx-tmpfile-keep
8830 application/*; echo "This is \e"%t\e" but \e
8831 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
8832 copiousoutput; x-mailx-noquote
8837 .Sx "HTML mail and MIME attachments" ,
8838 .Sx "The mime.types files" ,
8841 .Va mime-counter-evidence ,
8842 .Va pipe-TYPE/SUBTYPE ,
8843 .Va pipe-EXTENSION .
8846 .\" .Ss "The .netrc file" {{{
8847 .Ss "The .netrc file"
8851 file contains user credentials for machine accounts.
8852 The default location in the user's
8854 directory may be overridden by the
8856 environment variable.
8857 The file consists of space, tabulator or newline separated tokens.
8858 \*(UA implements a parser that supports a superset of the original BSD
8859 syntax, but users should nonetheless be aware of portability glitches
8860 of that file format, shall their
8862 be usable across multiple programs and platforms:
8865 .Bl -bullet -compact
8867 BSD doesn't support single, but only double quotation marks, e.g.,
8868 .Ql password="pass with spaces" .
8870 BSD (only?) supports escaping of single characters via a backslash
8871 (e.g., a space can be escaped via
8873 in- as well as outside of a quoted string.
8875 BSD doesn't require the final quotation mark of the final user input token.
8877 The original BSD (Berknet) parser also supported a format which allowed
8878 tokens to be separated with commas \(en whereas at least Hewlett-Packard
8879 still seems to support this syntax, \*(UA does not!
8881 As a non-portable extension some widely-used programs support
8882 shell-style comments: if an input line starts, after any amount of
8883 whitespace, with a number sign
8885 then the rest of the line is ignored.
8887 Whereas other programs may require that the
8889 file is accessible by only the user if it contains a
8895 \*(UA will always require these strict permissions.
8899 Of the following list of supported tokens \*(UA only uses (and caches)
8904 At runtime the command
8906 can be used to control \*(UA's
8910 .Bl -tag -width password
8911 .It Cd machine Ar name
8912 The hostname of the entries' machine, lowercase-normalized by \*(UA
8914 Any further file content, until either end-of-file or the occurrence
8919 first-class token is bound (only related) to the machine
8922 As an extension that shouldn't be the cause of any worries
8923 \*(UA supports a single wildcard prefix for
8925 .Bd -literal -offset indent
8926 machine *.example.com login USER password PASS
8927 machine pop3.example.com login USER password PASS
8928 machine smtp.example.com login USER password PASS
8934 .Ql pop3.example.com ,
8938 .Ql local.smtp.example.com .
8939 Note that in the example neither
8940 .Ql pop3.example.com
8942 .Ql smtp.example.com
8943 will be matched by the wildcard, since the exact matches take
8944 precedence (it is however faster to specify it the other way around).
8949 except that it is a fallback entry that is used shall none of the
8950 specified machines match; only one default token may be specified,
8951 and it must be the last first-class token.
8953 .It Cd login Ar name
8954 The user name on the remote machine.
8956 .It Cd password Ar string
8957 The user's password on the remote machine.
8959 .It Cd account Ar string
8960 Supply an additional account password.
8961 This is merely for FTP purposes.
8963 .It Cd macdef Ar name
8965 A macro is defined with the specified
8967 it is formed from all lines beginning with the next line and continuing
8968 until a blank line is (consecutive newline characters are) encountered.
8971 entries cannot be utilized by multiple machines, too, but must be
8972 defined following the
8974 they are intended to be used with.)
8977 exists, it is automatically run as the last step of the login process.
8978 This is merely for FTP purposes.
8985 .\" .Sh EXAMPLES {{{
8988 .\" .Ss "An example configuration" {{{
8989 .Ss "An example configuration"
8991 .Bd -literal -offset indent
8992 # This example assumes v15.0 compatibility mode
8995 # Where are the up-to-date SSL certificates?
8996 #set ssl-ca-dir=/etc/ssl/certs
8997 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8999 # (Since we manage up-to-date ones explicitly, don't use any,
9000 # possibly outdated, default certificates shipped with OpenSSL
9001 set ssl-no-default-ca
9003 # Don't use protocols older than TLS v1.2.
9004 # Change this only when the remote server doesn't support it:
9005 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
9006 # such explicit exceptions, then
9007 set ssl-protocol="-ALL,+TLSv1.2"
9009 # Explicitly define the list of ciphers, which may improve security,
9010 # especially with protocols older than TLS v1.2. See ciphers(1).
9011 # Hint: it is important to include "@STRENGTH": only with it the
9012 # final list will be sorted by algorithm strength.
9013 # This is an example: in reality it is possibly best to only use
9014 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
9015 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
9016 !MD5:!RC4:!EXPORT:@STRENGTH"
9018 # Request strict transport security checks!
9019 set ssl-verify=strict
9021 # Essential setting: select allowed character sets
9022 set sendcharsets=utf-8,iso-8859-1
9024 # A very kind option: when replying to a message, first try to
9025 # use the same encoding that the original poster used herself!
9026 set reply-in-same-charset
9028 # When replying to or forwarding a message the comment and name
9029 # parts of email addresses are removed unless this variable is set
9032 # When sending messages, wait until the Mail-Transfer-Agent finishs.
9033 # Only like this you'll be able to see errors reported through the
9034 # exit status of the MTA (including the builtin SMTP one)!
9037 # Only use builtin MIME types, no mime.types(5) files
9038 set mimetypes-load-control
9040 # Default directory where we act in (relative to $HOME)
9042 # A leading "+" (often) means: under *folder*
9043 # *record* is used to save copies of sent messages
9044 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
9046 # Make "file mymbox" and "file myrec" go to..
9047 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
9049 # Not really optional, e.g., for S/MIME
9050 set from="Your Name <address@exam.ple>"
9052 # It may be necessary to set hostname and/or smtp-hostname
9053 # if the "SERVER" of smtp and "domain" of from don't match.
9054 # The `urlencode' command can be used to encode USER and PASS
9055 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
9056 smtp-auth=login/plain... \e
9059 # Never refuse to start into interactive mode, and more
9061 colour-pager crt= \e
9062 followup-to followup-to-honour=ask-yes \e
9063 history-file=+.\*(uAhist history-size=-1 history-gabby \e
9064 mime-counter-evidence=0xE \e
9065 prompt='?\e?[\e$ \e@]\e& ' \e
9066 reply-to-honour=ask-yes
9068 # When `t'yping messages, show only these headers
9069 # (use `T'ype for all headers and `S'how for raw message)
9070 retain date from to cc subject
9072 # Some mailing lists
9073 mlist @xyz-editor\e.xyz$ @xyzf\e.xyz$
9074 mlsubscribe ^xfans@xfans\e.xyz$
9076 # A real life example of a very huge free mail provider
9078 set from="Your Name <address@examp.ple>"
9079 # (The plain smtp:// proto is optional)
9080 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
9083 # Here is a pretty large one which does not allow sending mails
9084 # if there is a domain name mismatch on the SMTP protocol level,
9085 # which would bite us if the value of from does not match, e.g.,
9086 # for people who have a sXXXXeforge project and want to speak
9087 # with the mailing list under their project account (in from),
9088 # still sending the message through their normal mail provider
9090 set from="Your Name <address@exam.ple>"
9091 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
9092 hostname=yaXXex.com smtp-hostname=
9095 # Create some new commands so that, e.g., `ls /tmp' will..
9106 ghost llS !ls -aFlrS
9109 # We don't support gpg(1) directly yet. But simple --clearsign'd
9110 # message parts can be dealt with as follows:
9113 set pipe-text/plain="@*#++=@\e
9114 < \e"${NAIL_FILENAME_TEMPORARY}\e" awk \e
9115 -v TMPFILE=\e"${NAIL_FILENAME_TEMPORARY}\e" '\e
9117 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
9120 print \e"--- GPG --verify ---\e";\e
9121 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
9122 print \e"--- GPG --verify ---\e";\e
9126 /^-----BEGIN PGP SIGNATURE-----/,\e
9127 /^-----END PGP SIGNATURE-----/ {\e
9137 !printf 'Key IDs to gpg --recv-keys: ';\e
9139 gpg --recv-keys ${keyids};
9145 When storing passwords in
9147 appropriate permissions should be set on this file with
9148 .Ql $ chmod 0600 \*(ur .
9151 is available user credentials can be stored in the central
9153 file instead; e.g., here is a different version of the example account
9154 that sets up SMTP and POP3:
9156 .Bd -literal -offset indent
9158 set from="Your Name <address@exam.ple>"
9160 #set agent-shell-lookup="gpg -d .pass.gpg"
9162 set smtp=smtps://smtp.yXXXXx.ru:465 \e
9163 smtp-hostname= hostname=yXXXXx.com
9164 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
9165 ghost xp fi pop3s://pop.yXXXXx.ru
9174 .Bd -literal -offset indent
9175 machine *.yXXXXx.ru login USER password PASS
9180 .Va agent-shell-lookup
9181 is available things could be diversified further by using encrypted
9182 password storage: for this, don't specify
9186 file and instead uncomment the line that defines agent lookup in the
9189 above, then create the encrypted password storage file
9192 .Bd -literal -offset indent
9195 $ eval `gpg-agent --daemon \e
9196 --pinentry-program=/usr/bin/pinentry-curses \e
9197 --max-cache-ttl 99999 --default-cache-ttl 99999`
9201 This configuration should now work just fine (use the
9203 command line option for a(n almost) dry-run):
9206 .Dl $ echo text | \*(uA -vv -AXandeX -s Subject user@exam.ple
9209 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
9210 .Ss "Signed and encrypted messages with S/MIME"
9212 \*(OP S/MIME provides two central mechanisms:
9213 message signing and message encryption.
9214 A signed message contains some data in addition to the regular text.
9215 The data can be used to verify that the message was sent using a valid
9216 certificate, that the sender's address in the message header matches
9217 that in the certificate, and that the message text has not been altered.
9218 Signing a message does not change its regular text;
9219 it can be read regardless of whether the recipient's software is able to
9223 It is thus usually possible to sign all outgoing messages if so desired.
9224 Encryption, in contrast, makes the message text invisible for all people
9225 except those who have access to the secret decryption key.
9226 To encrypt a message, the specific recipient's public encryption key
9228 It is therefore not possible to send encrypted mail to people unless their
9229 key has been retrieved from either previous communication or public key
9231 A message should always be signed before it is encrypted.
9232 Otherwise, it is still possible that the encrypted message text is
9236 A central concept to S/MIME is that of the certification authority (CA).
9237 A CA is a trusted institution that issues certificates.
9238 For each of these certificates it can be verified that it really
9239 originates from the CA, provided that the CA's own certificate is
9241 A set of CA certificates is usually delivered with OpenSSL and installed
9243 If you trust the source of your OpenSSL software installation,
9244 this offers reasonable security for S/MIME on the Internet.
9246 .Va ssl-no-default-ca
9250 .Va smime-ca-dir . )
9251 In general, a certificate cannot be more secure than the method its CA
9252 certificate has been retrieved with, though.
9253 Thus if you download a CA certificate from the Internet,
9254 you can only trust the messages you verify using that certificate as
9255 much as you trust the download process.
9258 The first thing you need for participating in S/MIME message exchange is
9259 your personal certificate, including a private key.
9260 The certificate contains public information, in particular your name and
9261 your email address(es), and the public key that is used by others to
9262 encrypt messages for you,
9263 and to verify signed messages they supposedly received from you.
9264 The certificate is included in each signed message you send.
9265 The private key must be kept secret.
9266 It is used to decrypt messages that were previously encrypted with your
9267 public key, and to sign messages.
9270 For personal use it is recommended that you get a S/MIME certificate
9271 from one of the major CAs on the Internet using your WWW browser.
9272 Many CAs offer such certificates for free.
9274 .Lk https://www.CAcert.org
9275 which issues client and server certificates to members of their
9276 community for free; their root certificate
9277 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9278 is often not in the default set of trusted CA root certificates, though,
9279 which means you will have to download their root certificate separately
9280 and ensure it is part of our S/MIME certificate validation chain by
9283 or as a vivid member of the
9285 But let's take a step-by-step tour on how to setup S/MIME with
9286 a certificate from CAcert.org despite this situation!
9289 First of all you will have to become a member of the CAcert.org
9290 community, simply by registrating yourself via the web interface.
9291 Once you are, create and verify all email addresses you want to be able
9292 to create signed and encrypted messages for/with using the corresponding
9293 entries of the web interface.
9294 Now ready to create S/MIME certificates, so let's create a new
9295 .Dq client certificate ,
9296 ensure to include all email addresses that should be covered by the
9297 certificate in the following web form, and also to use your name as the
9301 Create a private key and a certificate request on your local computer
9302 (please see the manual pages of the used commands for more in-depth
9303 knowledge on what the used arguments etc. do):
9306 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9309 Afterwards copy-and-paste the content of
9311 into the certificate-request (CSR) field of the web form on the
9312 CAcert.org website (you may need to unfold some
9313 .Dq advanced options
9314 to see the corresponding text field).
9315 This last step will ensure that your private key (which never left your
9316 box) and the certificate belong together (through the public key that
9317 will find its way into the certificate via the certificate-request).
9318 You are now ready and can create your CAcert certified certificate.
9319 Download and store or copy-and-paste it as
9324 In order to use your new S/MIME setup you will have to create
9325 a combined private key/public key (certificate) file:
9328 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9331 This is the file \*(UA will work with.
9332 If you have created your private key with a passphrase then \*(UA will
9333 ask you for it whenever a message is signed or decrypted.
9334 Set the following variables to henceforth use S/MIME (setting
9336 is of interest for verification only):
9338 .Bd -literal -offset indent
9339 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9340 smime-sign-cert=ME@HERE.com.paired \e
9341 smime-sign-message-digest=SHA256 \e
9346 From each signed message you send, the recipient can fetch your
9347 certificate and use it to send encrypted mail back to you.
9348 Accordingly if somebody sends you a signed message, you can do the same,
9351 command to check the validity of the certificate.
9354 Variables of interest for S/MIME signing:
9358 .Va smime-crl-file ,
9359 .Va smime-no-default-ca ,
9361 .Va smime-sign-cert ,
9362 .Va smime-sign-include-certs
9364 .Va smime-sign-message-digest .
9367 After it has been verified save the certificate via
9369 and tell \*(UA that it should use it for encryption for further
9370 communication with that somebody:
9372 .Bd -literal -offset indent
9374 set smime-encrypt-USER@HOST=FILENAME \e
9375 smime-cipher-USER@HOST=AES256
9379 Additional variables of interest for S/MIME en- and decryption:
9382 .Va smime-encrypt-USER@HOST .
9385 You should carefully consider if you prefer to store encrypted messages
9387 If you do, anybody who has access to your mail folders can read them,
9388 but if you do not, you might be unable to read them yourself later if
9389 you happen to lose your private key.
9392 command saves messages in decrypted form, while the
9396 commands leave them encrypted.
9399 Note that neither S/MIME signing nor encryption applies to message
9400 subjects or other header fields yet.
9401 Thus they may not contain sensitive information for encrypted messages,
9402 and cannot be trusted even if the message content has been verified.
9403 When sending signed messages,
9404 it is recommended to repeat any important header information in the
9408 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9409 .Ss "Using CRLs with S/MIME or SSL/TLS"
9411 \*(OP Certification authorities (CAs) issue certificate revocation
9412 lists (CRLs) on a regular basis.
9413 These lists contain the serial numbers of certificates that have been
9414 declared invalid after they have been issued.
9415 Such usually happens because the private key for the certificate has
9417 because the owner of the certificate has left the organization that is
9418 mentioned in the certificate, etc.
9419 To seriously use S/MIME or SSL/TLS verification,
9420 an up-to-date CRL is required for each trusted CA.
9421 There is otherwise no method to distinguish between valid and
9422 invalidated certificates.
9423 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9424 the Internet, so you have to retrieve them by some external mechanism.
9427 \*(UA accepts CRLs in PEM format only;
9428 CRLs in DER format must be converted, like, e.\|g.:
9431 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9434 To tell \*(UA about the CRLs, a directory that contains all CRL files
9435 (and no other files) must be created.
9440 variables, respectively, must then be set to point to that directory.
9441 After that, \*(UA requires a CRL to be present for each CA that is used
9442 to verify a certificate.
9445 .\" .Ss "Handling spam" {{{
9448 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9449 identification of, and, in general, dealing with spam messages.
9450 A precondition of most commands in order to function is that the
9452 variable is set to one of the supported interfaces.
9453 Once messages have been identified as spam their (volatile)
9455 state can be prompted: the
9459 message specifications will address respective messages and their
9461 entries will be used when displaying the
9463 in the header display.
9468 rates the given messages and sets their
9471 If the spam interface offers spam scores those can also be displayed in
9472 the header display by including the
9482 will interact with the Bayesian filter of the chosen interface and learn
9483 the given messages as
9487 respectively; the last command can be used to cause
9489 of messages; it adheres to their current
9491 state and thus reverts previous teachings.
9496 will simply set and clear, respectively, the mentioned volatile
9498 message flag, without any interface interaction.
9505 .Va spam-interface Ns s
9509 require a running instance of the
9511 server in order to function, started with the option
9513 shall Bayesian filter learning be possible.
9515 only works via a local path-based
9517 socket, but otherwise the following will be equivalently fine:
9519 .Bd -literal -offset indent
9520 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9521 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9522 --daemonize [--local] [--allow-tell]
9526 Thereafter \*(UA can make use of these interfaces:
9528 .Bd -literal -offset indent
9529 $ \*(uA -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9530 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9532 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9533 -Sspamc-command=/usr/local/bin/spamc \e
9534 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9536 $ \*(uA -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9537 -Sspamc-command=/usr/local/bin/spamc \e
9538 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9542 Using the generic filter approach allows usage of programs like
9546 Here is an example for the former, requiring it to be accessible via
9549 .Bd -literal -offset indent
9550 $ \*(uA -Sspam-interface=filter -Sspam-maxsize=500000 \e
9551 -Sspamfilter-ham="bogofilter -n" \e
9552 -Sspamfilter-noham="bogofilter -N" \e
9553 -Sspamfilter-nospam="bogofilter -S" \e
9554 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9555 -Sspamfilter-spam="bogofilter -s" \e
9556 -Sspamfilter-rate-scanscore="1;^(.+)$"
9560 Because messages must exist on local storage in order to be scored (or
9561 used for Bayesian filter training), it is possibly a good idea to
9562 perform the local spam check last:
9564 .Bd -literal -offset indent
9565 define spamdelhook {
9567 spamset (header x-dcc-brand-metrics "bulk")
9568 # Server-side spamassassin(1)
9569 spamset (header x-spam-flag "YES")
9570 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9576 set folder-hook-FOLDER=spamdelhook
9580 See also the documentation for the variables
9581 .Va spam-interface , spam-maxsize ,
9582 .Va spamc-command , spamc-arguments , spamc-user ,
9583 .Va spamd-socket , spamd-user ,
9584 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9587 .Va spamfilter-rate-scanscore .
9595 .\" .Ss "\*(UA shortly hangs on startup" {{{
9596 .Ss "\*(UA shortly hangs on startup"
9598 This can have two reasons, one is the necessity to wait for a file lock
9599 and can't be helped, the other being that \*(UA calls the function
9601 in order to query the nodename of the box (sometimes the real one is
9602 needed instead of the one represented by the internal variable
9604 You may have varying success by ensuring that the real hostname and
9608 or, more generally, that the name service is properly setup \(en
9611 return what you'd expect?
9612 Does this local hostname has a domain suffix?
9613 RFC 6762 standardized the link-local top-level domain
9617 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9618 .Ss "I can't login to Google mail a.k.a. GMail"
9620 Since 2014 some free service providers classify programs as
9622 unless they use a special authentification method (OAuth 2.0) which
9623 wasn't standardized for non-HTTP protocol authentication token query
9624 until August 2015 (RFC 7628).
9627 Different to Kerberos / GSSAPI, which is developed since the mid of the
9628 1980s, where a user can easily create a local authentication ticket for
9629 her- and himself with the locally installed
9631 program, that protocol has no such local part but instead requires
9632 a world-wide-web query to create or fetch a token; since there is no
9633 local cache this query has to be performed whenever \*(UA is invoked
9634 from the command line (in interactive sessions situation may differ).
9637 \*(UA doesn't support OAuth.
9638 Because of this it is necessary to declare \*(UA a
9640 (on the providers account web page) in order to read and send mail.
9641 However, it also seems possible to take the following steps instead:
9646 give the provider the number of a mobile phone,
9649 .Dq 2-Step Verification ,
9651 create an application specific password (16 characters), and
9653 use that special password instead of your real Google account password in
9654 S-nail (for more on that see the section
9655 .Sx "On URL syntax and credential lookup" ) .
9661 .\" .Sh "SEE ALSO" {{{
9679 .Xr spamassassin 1 ,
9705 M. Douglas McIlroy writes in his article
9706 .Dq A Research UNIX Reader: Annotated Excerpts \
9707 from the Programmer's Manual, 1971-1986
9710 command already appeared in First Edition
9714 .Bd -ragged -offset indent
9715 Electronic mail was there from the start.
9716 Never satisfied with its exact behavior, everybody touched it at one
9717 time or another: to assure the safety of simultaneous access, to improve
9718 privacy, to survive crashes, to exploit uucp, to screen out foreign
9719 freeloaders, or whatever.
9720 Not until v7 did the interface change (Thompson).
9721 Later, as mail became global in its reach, Dave Presotto took charge and
9722 brought order to communications with a grab-bag of external networks
9728 Mail was written in 1978 by Kurt Shoens and developed as part of the
9731 distribution until 1995.
9732 Mail has then seen further development in open source
9734 variants, noticeably by Christos Zoulas in
9736 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9737 Ritter in the years 2000 until 2008.
9738 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9739 This man page is derived from
9740 .Dq The Mail Reference Manual
9741 that was originally written by Kurt Shoens.
9748 .An "Christos Zoulas" ,
9749 .An "Gunnar Ritter" ,
9750 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9752 .Mt s-mailx@sdaoden.eu ) .
9758 The character set conversion uses and relies upon the
9761 Its functionality differs widely between the various system environments
9765 Limitations with POP3 mailboxes are:
9766 It is not possible to edit messages, they can only be copied and deleted.
9767 The line count for the header display is only appropriate if the entire
9768 message has been downloaded from the server.
9769 The status field of a message is maintained by the server between
9770 connections; some servers do not update it at all, and with a server
9773 command will not cause the message status to be reset.
9778 variable have no effect.
9779 It is not possible to rename or to remove POP3 mailboxes.
9786 is typed while a POP3 operation is in progress, \*(UA will wait
9787 until the operation can be safely aborted, and will then return to the
9788 command loop and print the prompt again.
9791 is typed while \*(UA is waiting for the operation to complete, the
9792 operation itself will be cancelled.
9793 In this case, data that has not been fetched yet will have to be fetched
9794 before the next command can be performed.
9795 If the cancelled operation was using an SSL/TLS encrypted channel,
9796 an error in the SSL transport will very likely result and render the
9797 connection unusable.
9800 As \*(UA is a mail user agent, it provides only basic SMTP services.
9801 If it fails to contact its upstream SMTP server, it will not make
9802 further attempts to transfer the message at a later time,
9803 and it does not leave other information about this condition than an
9804 error message on the terminal and an entry in
9806 This is usually not a problem if the SMTP server is located in the same
9807 local network as the computer on which \*(UA is run.
9808 However, care should be taken when using a remote server of an ISP;
9809 it might be better to set up a local SMTP server then which just acts as
9813 \*(UA immediately contacts the SMTP server (or
9815 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9816 servers usually provide much more elaborated delay handling than \*(UA
9817 could perform as a client.
9825 from the distribution or the repository.
9827 After deleting some message of a POP3 mailbox the header summary falsely
9828 claims that there are no messages to display, you need to perform
9829 a scroll or dot movement to restore proper state.
9831 In threaded display a power user may encounter crashes very
9832 occasionally (this is may and very).