1 .\"@ nail.1 - S-nail(1) reference manual.
3 .\" Copyright (c) 1980, 1990, 1993
4 .\" The Regents of the University of California. All rights reserved.
6 .\" Gunnar Ritter. All rights reserved.
7 .\" Copyright (c) 2012 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
12 .\" 1. Redistributions of source code must retain the above copyright
13 .\" notice, this list of conditions and the following disclaimer.
14 .\" 2. Redistributions in binary form must reproduce the above copyright
15 .\" notice, this list of conditions and the following disclaimer in the
16 .\" documentation and/or other materials provided with the distribution.
17 .\" 3. All advertising materials mentioning features or use of this software
18 .\" must display the following acknowledgement:
19 .\" This product includes software developed by the University of
20 .\" California, Berkeley and its contributors.
21 .\" This product includes software developed by Gunnar Ritter
22 .\" and his contributors.
24 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS 'AS IS' AND
25 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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29 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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33 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 .\" S-nail(1): v14.8.10 / 2016-08-20
49 .\" If not ~/.mailrc, it breaks POSIX compatibility. And adjust main.c.
54 .ds OU [no v15-compat]
55 .ds ID [v15 behaviour may differ]
66 .Nd send and receive Internet mail
78 .Op Fl a Ar attachment
81 .Op Fl q Ar quote-file
83 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
88 .Op Fl Fl \: Ar mta-option ...
96 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
99 .Op Fl Fl \: Ar mta-option ...
105 .Op Fl L Ar spec-list
106 .Op Fl r Ar from-addr
107 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
110 .Op Fl Fl \: Ar mta-option ...
115 .Mx -toc -tree html pdf ps xhtml
118 .\" .Sh DESCRIPTION {{{
121 .Bd -filled -compact -offset indent
122 .Sy Compatibility note:
123 S-nail (\*(UA) will wrap up into \%S-mailx in v15.0 (circa 2018).
124 A partial set of compatibility options exist, tagged as \*(IN and \*(OU.
125 To choose upward compatible behaviour, please set the internal variable
127 Anything which will vanish in v15.0 is tagged \*(OB, and using
129 will print warnings for many use cases of obsolete features.
133 \*(UA is a mail processing system with a command syntax reminiscent of
135 with lines replaced by messages.
136 It is intended to provide the functionality of the POSIX
138 command and offers (mostly optional) extensions for line editing, IDNA,
139 MIME, S/MIME, SMTP and POP3 (and IMAP).
140 It is usable as a mail batch language.
142 .\" .Ss "Options" {{{
145 .Bl -tag -width ".Fl _ Ar _ccount"
150 command (see below) for
152 after the startup files have been read.
156 Attach the given file to the message.
157 The same filename conventions as described in the section
159 apply: shell word expansion is restricted to the tilde
164 not be accessible but contain a
166 character, then anything after the
168 is assumed to specify the input character set and anything before
170 the filename: this is the only option to specify the input character set
171 (and don't perform any character set conversion) for text attachments
172 from the command line, not using the
174 tilde escape command.
178 Make standard input and standard output line-buffered.
182 Send a blind carbon copy to
184 Can be used multiple times, but it is also possible to give
185 a comma-separated list of receivers in a single argument, proper shell
186 quoting provided, e.g.,
187 .Ql -b """qrec1 , rec2,rec3, Ex <am@ple>""" .
189 .Sx "On sending mail, and non-interactive mode" .
193 Send carbon copies to the given receiver(s).
194 Can be used multiple times.
206 variable which enables debug messages and disables message delivery,
207 among others; effectively turns almost any operation into a dry-run.
213 variable and thus discard messages with an empty message part body.
214 This is useful for sending messages from scripts.
218 Just check if mail is present (in the specified or system mailbox).
219 If yes, return an exit status of zero, a non-zero value otherwise.
220 To restrict the set of mails to consider in this evaluation a message
221 specification can be added with the option
226 Save the message to send in a file named after the local part of the
227 first recipient's address (instead of in
232 Read in the contents of the user's
234 (or the specified file) for processing;
235 when \*(UA is quit, it writes undeleted messages back to this file
239 Some special conventions are recognized for the string
241 which are documented for the
246 is not a direct argument to the flag
248 but is instead taken from the command line after option processing has
252 that starts with a hyphen, prefix it with a (relative) path, as in
253 .Ql ./-hyphenbox.mbox .
257 Print a summary of the
259 of all messages in the specified or system mailbox and exit.
260 A configurable summary view is available via the
266 Print a short usage summary.
267 Because of widespread use a
269 argument will have the same effect.
275 variable to ignore tty interrupt signals.
278 .It Fl L Ar spec-list
279 Print a summary of all
281 of only those messages in the specified or system mailbox that match the
286 .Sx "Specifying messages"
293 option has been given in addition no header summary is produced,
294 but \*(UA will instead indicate via its exit status wether
300 note that any verbose output is suppressed in this mode and must instead
301 be enabled explicitly (e.g., by using the option
308 variable and thus inhibit initial display of message headers when
309 reading mail or editing a mail folder.
316 This option should be activated for \*(UA scripts that are invoked on
317 more than one machine, because the contents of that file may differ
319 (The same behaviour can be achieved by setting the
320 .Ev NAIL_NO_SYSTEM_RC
321 environment variable.)
325 Start the message with the contents of the specified file.
326 May be given in send mode only.
330 Any folder opened will be in read-only mode.
336 is a valid address then it specifies the envelope sender address to be
339 when a message is send.
342 include a user name, comments etc., then the components will be
343 separated and the name part will be passed to the MTA individually via
347 will also be assigned to the
349 variable, just as if additionally
351 had been specified (therefore affecting SMTP data transfer, too).
353 If instead an empty string is passed as
355 then the content of the variable
357 will be evaluated and used for this purpose whenever the MTA is
359 Note that \*(UA by default, without
361 that is, neither passes
365 flags to the MTA by itself.
368 .It Fl S Ar variable Ns Op = Ns value
369 Sets the internal option
371 and, in case of a value option, assigns
374 Even though variables set via
376 may be overwritten from within resource files,
377 the command line setting will be reestablished after all resource files
382 Specify the subject of the to-be-sent message.
386 The message to be sent is expected to contain a message header with
391 fields giving its recipients, which will be added to those given on the
393 If a message subject is specified via
395 then it'll be used in favour of one given on the command line.
407 Note you can also specify
411 and the envelope address possibly specified with the option
414 The following, which are normally created automatically based
415 upon the message context, can also be specified:
420 .Ql Mail-Followup-To:
421 (special address massage will however still occur for the latter).
425 Read the system mailbox of
427 (appropriate privileges presumed), and
430 in some aspects, e.g. in respect to
439 Print \*(UA's version and exit.
445 option enables display of some informational context messages.
446 Using it twice increases the level of verbosity.
452 to the list of commands to be executed before normal operation starts.
456 .Va batch-exit-on-error ;
457 the only possibility to execute commands in non-interactive mode when
458 reading startup files is actively prohibited.
464 even if not in interactive mode.
468 This sets several variables to prepare \*(UA for working in (most likely
469 non-interactive) batch mode:
481 It also enables processing of
482 .Sx "TILDE ESCAPES" .
483 E.g., the following should send an email message to
485 .Bd -literal -offset indent
486 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en.\enx\en' | \e
487 LC_ALL=C MAILRC=/dev/null \*(ua -n -# -Snosave
492 This flag forces termination of option processing in order to prevent
495 It also forcefully puts \*(UA into send mode, see
496 .Sx "On sending mail, and non-interactive mode" .
500 In the above list of supported command line options,
501 .Fl D , d , E , i , N
504 are implemented by means of setting the respective option, as via
507 .Op Ar mta-option ...
509 arguments that are given at the end of the command line after a
511 separator will be passed through to the mail-transfer-agent (MTA) and
512 persist for an entire (interactive) session \(en if the setting of
514 allows their recognition;
515 MTA arguments can also be specified in the variable
516 .Va sendmail-arguments ;
517 find MTA interaction described in more detail in the documentation of
519 MTA arguments are ignored when mail is send via SMTP data transfer.
522 .\" .Ss "A starter" {{{
525 \*(UA is a direct descendant of
527 Mail, a successor of the Research
530 .Dq was there from the start
535 Mail reference manual begins with the following words:
537 .Bd -ragged -offset indent
538 Mail provides a simple and friendly environment for sending and
540 It divides incoming mail into its constituent messages and allows the
541 user to deal with them in any order.
542 In addition, it provides a set of
544 -like commands for manipulating messages and sending mail.
545 Mail offers the user simple editing capabilities to ease the composition
546 of outgoing messages, as well as providing the ability to define and
547 send to names which address groups of users.
551 \*(UA is thus the user side of the
553 mail system, whereas the system side (mail-transfer-agent, MTA) was
554 traditionally taken by
560 are often used for this purpose instead.
561 If the \*(OPal SMTP is included in the
563 of \*(UA then the system side is not a mandatory precondition for mail
567 Because \*(UA strives for compliance with POSIX
569 it is likely that some configuration settings have to be adjusted before
570 using it is a smooth experience.
573 file already bends those standard settings a bit towards more user
574 friendliness and safety, e.g., it sets the
578 variables in order to suppress the automatic moving of messages to
580 that would otherwise occur (see
581 .Sx "Message states" )
584 to not remove empty files in order not to mangle file permissions when
585 files eventually get recreated.
588 option so that by default file grouping (via the
590 prefix as documented also for
595 contains some further suggestions.
598 .\" .Ss "On sending mail, and non-interactive mode" {{{
599 .Ss "On sending mail, and non-interactive mode"
601 To send a message to one or more people, using a local
602 mail-transfer-agent (MTA; the executable path can be set via
604 or the \*(OPal builtin SMTP (set and see the variable
606 transport to actually deliver the generated mail message, \*(UA can be
607 invoked with arguments which are the names of people to whom the mail
610 .Bd -literal -offset indent
611 $ \*(ua -s Subject -a attachm.ent bill@host1 'Bob <bob@host2>'
612 # But... try it in an isolated dry-run mode first
613 $ LC_ALL=C MAILRC=/dev/null \e
614 \*(ua -n -d -vv -Sfrom="me <he@re>" \e
615 -b bcc@exam.ple -c cc@exam.ple \e
616 -s Subject -. "(Lovely) Bob <bob@host2>"
620 The command line options
624 can be used to add (blind) carbon copy receivers.
625 Almost always lists of addresses can be given where an address is
627 whereas comma-separated lists should be given, e.g.,
628 .Ql -c """r1@exam.ple , r2@exam.ple,r3@exam.ple""" ,
629 that very example could also be given as the whitespace-separated list
630 .Ql -c """r1@exam.ple r2@exam.ple r3@exam.ple""" ,
631 but which for obvious reasons would not work for
632 .Ql -c """R1 <r1@exam.ple>, R2 (heh!) <r2@exam.ple>""" .
635 The user is then expected to type in the message contents.
636 In this compose mode \*(UA treats lines beginning with the character
638 special \(en these are so-called
640 which can be used to read in files, process shell commands, add and edit
641 attachments and more; e.g., the tilde escape
643 will start the text editor to revise the message in it's current state,
645 allows editing of the message recipients and
647 gives an overview of available tilde escapes.
650 at the beginning of an empty line leaves compose mode and causes the
651 message to be send, whereas typing control-C
653 twice will abort the current letter (saving its contents in the file
661 A number of variables can be used to alter default behavior; e.g.,
666 will automatically startup a text editor when compose mode is entered,
668 will cause the user to be prompted actively for carbon-copy recipients
671 option will allow leaving compose mode by writing a line consisting
676 Very important, though, is to define which
678 may be used when sending messages, usually by setting the option
681 having read the section
682 .Sx "The mime.types files"
683 to understand how the MIME-type of outgoing attachments is classified
684 and the knowledge that messages are sent asynchronously unless
686 is set: only with it MTA delivery errors will be recognizable.
691 is often necessary (e.g., in conjunction with
693 or desirable, you may want to do some dry-run tests before you go.
694 Saving a copy of the sent messages in a
696 may also be desirable \(en as for most mailbox file targets some
697 special conventions are recognized, see the
699 command for more on that.
701 .Sx "On URL syntax and credential lookup"
702 will spread some light on the
704 variable chains as well as on using URLs for accessing protocol-specific
709 contains an example configuration for sending messages via some of the
710 well-known public mail providers;
711 note it also gives a compact overview on how to setup a secure SSL/TLS
715 Message recipients (as specified on the command line or defined in
720 may not only be email addressees but can also be names of mailboxes and
721 even complete shell command pipe specifications.
722 Proper (shell) quoting is necessary, e.g., to embed whitespace characters.
723 (Recall that \*(UA deals with mail standards, therefore those define the
724 rules with which content is interpreted.)
727 is not set then only network addresses (see
729 for a description of mail addresses) and plain user names (including MTA
730 aliases) may be used, other types will be filtered out, giving a warning
733 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
734 .\" grep the latter for the complete picture
738 is set then extended recipient addresses will optionally be accepted:
739 Any name which starts with a vertical bar
741 character specifies a command pipe \(en the command string following the
743 is executed and the message is sent to its standard input;
744 Likewise, any name that starts with the character slash
746 or the character sequence dot slash
748 is treated as a file, regardless of the remaining content.
749 Any other name which contains an at sign
751 character is treated as a network address;
752 Any other name which starts with a plus sign
754 character specifies a mailbox name;
755 Any other name which contains a slash
757 character but no exclamation mark
761 character before also specifies a mailbox name;
762 What remains is treated as a network address.
764 .Bd -literal -offset indent
765 $ echo bla | \*(ua -Sexpandaddr -s test ./mbox.mbox
766 $ echo bla | \*(ua -Sexpandaddr -s test '|cat >> ./mbox.mbox'
767 $ echo safe | LC_ALL=C MAILRC=/dev/null \e
768 \*(ua -n -Sv15-compat -Ssendwait -Snosave \e
769 -Sexpandaddr=fail,-all,+addr -s test \e
774 It is possible to create personal distribution lists via the
776 command, so that, for instance, the user can send mail to
778 and have it go to a group of people:
781 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
784 Please note that this mechanism has nothing in common with the system
785 wide aliases that may be used by the local MTA (mail-transfer-agent),
786 which are subject to the
790 and are often tracked in a file
796 Personal aliases will be expanded by \*(UA before the message is sent,
797 and are thus a convenient alternative to specifying each addressee by
801 To avoid environmental noise scripts should
803 \*(UA from any configuration files and create a script-local
804 environment, either by pointing the
806 variable to a custom configuration file, or by using the
808 command line option to specify variables:
810 .Bd -literal -offset indent
811 $ env LC_ALL=C MAILRC=/dev/null password=NOTSECRET \e
812 \*(ua -n -Sv15-compat -Ssendwait -Snosave \e
813 -Sexpandaddr=fail,-all,+addr \e
814 -S 'smtp=smtps://mylogin@some.host:465' -Ssmtp-auth=login \e
815 -S 'from=scriptreply@domain' \e
816 -s 'subject' -a attachment_file \e
817 -. "Recipient 1 <recipient1@domain>" recipient2@domain \e
822 In interactive mode, which is introduced in the next section, messages
823 can be send by calling the
825 command with a list of recipient addresses \(em the semantics are
826 completely identical to non-interactive message sending, except that
827 it is likely necessary to separate recipient lists with commas:
829 .Bd -literal -offset indent
830 $ \*(ua -d -Squiet -Semptystart
831 "/var/spool/mail/user": 0 messages
832 ? mail "Recipient 1 <recipient1@domain>", recipient2@domain
833 ? # Will do the right thing (tm)
834 ? m recipient1@domain recipient2@domain
838 .\" .Ss "On reading mail, and interactive mode" {{{
839 .Ss "On reading mail, and interactive mode"
841 When invoked without addressees \*(UA enters interactive mode in which
843 When used like that the user's system mailbox (see the command
845 for an in-depth description of the different mailbox types that exist)
846 is read in and a one line header of each message therein is displayed.
847 The visual style of this summary of
849 can be adjusted through the variable
851 and the possible sorting criterion via
853 If the initially opened mailbox is empty \*(UA will instead exit
854 immediately (after displaying a message) unless the variable
863 will give a listing of all available commands and
865 will give a summary of some common ones.
866 If the \*(OPal documentation strings are available one can type
868 and see the actual expansion of
870 and what it's purpose is, i.e., commands can be abbreviated
871 (note that POSIX defines some abbreviations, so that the alphabetical
872 order of commands doesn't necessarily relate to the abbreviations; it is
873 possible to define overwrites with the
878 Messages are given numbers (starting at 1) which uniquely identify
879 messages; the current message \(en the
881 \(en will either be the first new message, or the first unread message,
882 or the first message of the mailbox; the option
884 will instead cause usage of the last message for this purpose.
889 ful of header summaries containing the
893 will print only the summaries of the given messages, defaulting to the
897 Messages can be printed with the
901 By default the current message
903 is printed, but like with most other commands it is possible to give
904 a fancy message specification (see
905 .Sx "Specifying messages" ) ,
908 will display all unread messages,
913 will print the messages 1 and 5,
915 will print the messages 1 through 5, and
919 will print the last and the next message, respectively.
920 By the way, using the command
922 in conjunction with a message specification is the way to perform
923 searching in \*(UA: the following will print the header summaries of all
924 messages which contain the given string in their subject, for example:
927 .Dl ? from """@Some subject to search for"""
930 In the default setup all header fields of a message will be printed,
931 but this can be changed: either by blacklisting a list of fields via
933 or by whitelisting only a given list with the
936 .Ql Ic \:retain Ns \0date from to cc subject .
937 In order to print all header fields of a message regardless of currently
938 active ignore or retain lists, use the command
942 controls wether and when \*(UA will use the configured
944 for printing instead of directly writing to the terminal (generally
946 Note that historically the global
948 not only adjusts the list of displayed headers, but also sets
952 Dependent upon the configuration a
953 .Sx "Command line editor"
954 aims at making user experience with the many
957 When reading the system mailbox or when
961 specified a mailbox explicitly prefixed with the special
963 modifier (propagating the mailbox to a primary one) then messages which
964 have been read will be moved to a secondary mailbox, the user's
966 file, automatically when the mailbox is left, either by changing the
967 active mailbox or by quitting \*(UA (also see
968 .Sx "Message states" )
969 \(en this automatic moving from a system or primary to the secondary
970 mailbox is not performed when the variable
975 After examining a message the user can also
979 to the sender and all recipients or
981 exclusively to the sender(s).
986 Note that when replying to or forwarding a message recipient addresses
987 will be stripped from comments and names unless the option
990 Deletion causes \*(UA to forget about the message;
991 This is not irreversible, though, one can
993 the message by giving its number,
994 or the \*(UA session can be ended by giving the
999 To end a mail processing session one may either issue
1001 to cause a full program exit, which possibly includes
1002 automatic moving of read messages to
1004 as well as updating the \*(OPal command line editor history file,
1007 instead in order to prevent any of these actions.
1010 .\" .Ss "HTML mail and MIME attachments" {{{
1011 .Ss "HTML mail and MIME attachments"
1013 Messages which are HTML-only get more and more common and of course many
1014 messages come bundled with a bouquet of MIME attachments.
1015 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1016 with HTML messages (see
1017 .Sx "The mime.types files" ) ,
1018 it normally can't deal with any of these itself, but instead programs
1019 need to become registered to deal with specific MIME types or file
1021 These programs may either prepare plain text versions of their input
1022 in order to enable \*(UA to display the content on the terminal,
1023 or display the content themselves, for example in a graphical window.
1026 To install an external handler program for a specific MIME type set an
1028 .Va pipe-TYPE/SUBTYPE
1029 variable; to instead define a handler for a specific file extension set
1032 variable \(en these handlers take precedence.
1033 \*(OPally \*(UA supports mail user agent configuration as defined in
1034 RFC 1524; this mechanism, documented in the section
1035 .Sx "The Mailcap files" ,
1036 will be queried for display or quote handlers if none of the former two
1037 .\" TODO v15-compat "will be" -> "is"
1038 did; it will be the sole source for handlers of other purpose.
1039 A last source for handlers may be the MIME type definition itself, if
1040 the \*(UA specific type-marker extension was used when defining the type
1043 (Many of the builtin MIME types do so by default.)
1047 .Va mime-counter-evidence
1048 can be set to improve dealing with faulty MIME part declarations as are
1049 often seen in real-life messages.
1050 E.g., to display a HTML message inline (that is, converted to a more
1051 fancy plain text representation than the builtin converter is capable to
1052 produce) with either of the text-mode browsers
1056 teach \*(UA about MathML documents and make it display them as plain
1057 text, and to open PDF attachments in an external PDF viewer,
1058 asynchronously and with some other magic attached:
1060 .Bd -literal -offset indent
1061 if $features !@ HTML-FILTER
1062 #set pipe-text/html="elinks -force-html -dump 1"
1063 set pipe-text/html="lynx -stdin -dump -force_html"
1064 # Display HTML as plain text instead
1065 #set pipe-text/html=@
1067 mimetype '@ application/mathml+xml mathml'
1068 set pipe-application/pdf="@&=@ \e
1069 trap \e"rm -f \e\e\e"${NAIL_FILENAME_TEMPORARY}\e\e\e"\e" EXIT;\e
1070 trap \e"trap \e\e\e"\e\e\e" INT QUIT TERM; exit 1\e" \e INT QUIT TERM;\e
1071 xpdf \e"${NAIL_FILENAME_TEMPORARY}\e""
1075 Note: special care must be taken when using such commands as mail
1076 viruses may be distributed by this method: if messages of type
1077 .Ql application/x-sh
1078 or files with the extension
1080 were blindly filtered through the shell, for example, a message sender
1081 could easily execute arbitrary code on the system \*(UA is running on.
1082 For more on MIME, also in respect to sending of messages, see the
1084 .Sx "The mime.types files" ,
1085 .Sx "The Mailcap files"
1090 .\" .Ss "Mailing lists" {{{
1093 \*(UA offers some support to ease handling of mailing lists.
1096 promotes all given arguments to known mailing lists, and
1098 sets their subscription attribute, creating them first as necessary.
1103 automatically, but only resets the subscription attribute.)
1104 Using the commands without arguments will print out (a subset of) all
1105 currently defined mailing lists.
1110 can be used to mark out messages with configured list addresses
1111 in the header display.
1114 \*(OPally mailing lists may also be specified as (extended) regular
1115 expressions, which allows matching of many addresses with a single
1117 However, all fully qualified list addresses are matched via a fast
1118 dictionary, whereas expressions are placed in (a) list(s) which is
1119 (are) matched sequentially.
1121 .Bd -literal -offset indent
1122 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1123 mlist a1@b1.c1 a2@b2.c2 .*@lists.c3$
1124 mlsubscribe a4@b4.c4 exact@lists.c3
1129 .Va followup-to-honour
1131 .Ql Mail-\:Followup-\:To:
1132 header is honoured when the message is being replied to (via
1138 controls wether this header is created when sending mails; it will be
1139 created automatically for a couple of reasons, too, like when the
1141 .Dq mailing list specific
1146 is used to respond to a message with its
1147 .Ql Mail-Followup-To:
1151 A difference in between the handling of known and subscribed lists is
1152 that the address of the sender is usually not part of a generated
1153 .Ql Mail-Followup-To:
1154 when addressing the latter, whereas it is for the former kind of lists.
1155 Usually because there are exceptions: say, if multiple lists are
1156 addressed and not all of them are subscribed lists.
1158 For convenience \*(UA will, temporarily, automatically add a list
1159 address that is presented in the
1161 header of a message that is being responded to to the list of known
1163 Shall that header have existed \*(UA will instead, dependend on the
1165 .Va reply-to-honour ,
1168 for this purpose in order to accept a list administrators' wish that
1169 is supposed to have been manifested like that (but only if it provides
1170 a single address which resides on the same domain as what is stated in
1174 .\" .Ss "Resource files" {{{
1175 .Ss "Resource files"
1177 Upon startup \*(UA reads in several resource files:
1179 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1182 System wide initialization file.
1183 Reading of this file can be suppressed, either by using the
1185 command line option, or by setting the environment variable
1186 .Ev NAIL_NO_SYSTEM_RC .
1190 File giving initial commands.
1191 A different file can be chosen by setting the environment variable
1194 .It Va NAIL_EXTRA_RC
1195 Can be used to define an optional startup file to be read after
1197 This variable is only honoured in certain circumstances (see its
1198 documentation for more).
1202 The content of these files is interpreted as follows:
1205 .Bl -bullet -compact
1207 A lines' leading whitespace is removed.
1209 Empty lines are ignored.
1211 Any other line is interpreted as a command.
1212 It may be spread over multiple input lines if the newline character is
1214 by placing a backslash character
1216 as the last character of the line; whereas any leading whitespace of
1217 follow lines is ignored, trailing whitespace before a escaped newline
1218 remains in the input.
1220 If the line (content) starts with the number sign
1222 then it is a comment-command \(en a real command! \(en and also ignored.
1223 This command is the only form of comment that is understood.
1229 .Bd -literal -offset indent
1230 # This line is a comment command. And y\e
1231 es, it is really continued here.
1238 .\" .Ss "Character sets" {{{
1239 .Ss "Character sets"
1241 \*(OP \*(UA detects the character set of the terminal by using
1242 mechanisms that are controlled by the
1247 should give an overview); the \*(UA internal variable
1249 will be set to the detected terminal character set accordingly
1250 and will thus show up in the output of the commands
1256 However, a user supplied
1258 value is not overwritten by this detection mechanism: this
1260 must be used if the detection doesn't work properly,
1261 and it may be used to adjust the name of the locale character set.
1262 E.g., on BSD systems one may use a locale with the character set
1263 ISO8859-1, which is not a valid name for this character set; to be on
1264 the safe side, one may set
1266 to the correct name, which is ISO-8859-1.
1269 Note that changing the value doesn't mean much beside that,
1270 since several aspects of the real character set are implied by the
1271 locale environment of the system,
1272 and that stays unaffected by the content of an overwritten
1275 (This is mostly an issue when interactively using \*(UA, though.
1276 It is actually possible to send mail in a completely
1278 locale environment, an option that \*(UA's test-suite uses excessively.)
1281 If no character set conversion capabilities have been compiled into
1284 doesn't include the term
1288 will be the only supported character set,
1289 it is simply assumed that it can be used to exchange 8-bit messages,
1290 and the rest of this section does not apply;
1291 it may however still be necessary to explicitly set it if automatic
1292 detection fails, since in that case it defaults to the mentioned
1293 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1297 When reading messages, their text is converted into
1299 as necessary in order to display them on the users terminal.
1300 Unprintable characters and invalid byte sequences are detected
1301 and replaced by proper substitution characters (unless the variable
1303 was set once \*(UA was started).
1305 .Va charset-unknown-8bit
1306 to deal with another hairy aspect of message interpretation.
1309 When sending messages all their parts and attachments are classified.
1310 Whereas no character set conversion is performed on those parts which
1311 appear to be binary data,
1312 the character set being used must be declared within the MIME header of
1313 an outgoing text part if it contains characters that do not conform to
1314 the set of characters that are allowed by the email standards.
1315 Permissible values for character sets can be declared using the
1319 which defines a catch-all last-resort fallback character set that is
1320 implicitly appended to the list of character-sets in
1324 When replying to a message and the variable
1325 .Va reply-in-same-charset
1326 is set then the character set of the message being replied to is tried
1328 And it is also possible to make \*(UA work even more closely related to
1329 the current locale setting automatically by using the variable
1330 .Va sendcharsets-else-ttycharset ,
1331 please see there for more information.
1334 All the specified character sets are tried in order unless the
1335 conversion of the part or attachment succeeds.
1336 If none of the tried (8-bit) character sets is capable to represent the
1337 content of the part or attachment,
1338 then the message will not be sent and its text will optionally be
1342 In general, if the message
1343 .Dq Cannot convert from a to b
1344 appears, either some characters are not appropriate for the currently
1345 selected (terminal) character set,
1346 or the needed conversion is not supported by the system.
1347 In the first case, it is necessary to set an appropriate
1349 locale and/or the variable
1353 The best results are usually achieved when \*(UA is run in a UTF-8
1354 locale on a UTF-8 capable terminal, in which case the full Unicode
1355 spectrum of characters is available.
1356 In this setup characters from various countries can be displayed,
1357 while it is still possible to use more simple character sets for sending
1358 to retain maximum compatibility with older mail clients.
1361 On the other hand the POSIX standard defines a locale-independent 7-bit
1362 .Dq portable character set
1363 that should be used when overall portability is an issue, the even more
1364 restricted subset named
1365 .Dq portable filename character set
1366 consisting of A-Z, a-z, 0-9, period
1375 .\" .Ss "Message states" {{{
1376 .Ss "Message states"
1378 \*(UA differentiates in between several different message states;
1379 the current state will be reflected in header summary displays if
1381 is configured to do so (via the internal variable
1383 and messages can also be selected and be acted upon depending on their
1385 .Sx "Specifying messages" ) .
1386 When operating on the system mailbox or in primary mailboxes opened with
1391 special actions, like the automatic moving of messages to the secondary
1393 mailbox may be applied when the mailbox is left (also implicitly via
1394 a successful exit of \*(UA, but not if the special command
1396 is used) \(en however, because this may be irritating to users which
1399 mail-user-agents, the default global
1405 variables in order to suppress this behaviour.
1407 .Bl -tag -width ".It Ql _reserved"
1409 Message has neither been viewed nor moved to any other state.
1410 Such messages are retained even in the system mailbox.
1413 Message has neither been viewed nor moved to any other state, but the
1414 message was present already when the mailbox has been opened last:
1415 Such messages are retained even in the system mailbox.
1418 The message has been processed by one of the following commands:
1438 commands may also cause the next message to be marked as read, depending
1444 command is used, messages that are in the system mailbox or in mailboxes
1445 which were opened with the special
1449 state when the mailbox is left will be saved in
1456 The message has been processed by one of the following commands:
1462 can be used to access such messages.
1465 The message has been processed by a
1467 command and it will be retained in its current location.
1470 The message has been processed by one of the following commands:
1476 command is used, messages that are in the system mailbox or in mailboxes
1477 which were opened with the special
1481 state when the mailbox is left will be deleted; they will be saved in
1489 .\" .Ss "Specifying messages" {{{
1490 .Ss "Specifying messages"
1497 can be given a list of message numbers as arguments to apply to a number
1498 of messages at once.
1501 deletes messages 1 and 2,
1504 will delete the messages 1 through 5.
1505 In sorted or threaded mode (see the
1509 will delete the messages that are located between (and including)
1510 messages 1 through 5 in the sorted/threaded order, as shown in the
1513 Multiple colon modifiers can be joined into one, e.g.,
1515 The following special message names exist:
1517 .Bl -tag -width ".It Ar _n_u"
1523 All old messages (any not in state
1548 All answered messages
1553 All messages marked as draft.
1555 \*(OP All messages classified as spam.
1557 \*(OP All messages with unsure spam classification.
1559 The current message, the so-called
1562 The message that was previously the current message.
1564 The parent message of the current message,
1565 that is the message with the Message-ID given in the
1567 field or the last entry of the
1569 field of the current message.
1571 The next previous undeleted message,
1572 or the next previous deleted message for the
1575 In sorted/threaded mode,
1576 the next previous such message in the sorted/threaded order.
1578 The next undeleted message,
1579 or the next deleted message for the
1582 In sorted/threaded mode,
1583 the next such message in the sorted/threaded order.
1585 The first undeleted message,
1586 or the first deleted message for the
1589 In sorted/threaded mode,
1590 the first such message in the sorted/threaded order.
1593 In sorted/threaded mode,
1594 the last message in the sorted/threaded order.
1598 selects the message addressed with
1602 is any other message specification,
1603 and all messages from the thread that begins at it.
1604 Otherwise it is identical to
1609 the thread beginning with the current message is selected.
1614 All messages that were included in the message list for the previous
1617 .It Ar / Ns Ar string
1618 All messages that contain
1620 in the subject field (case ignored).
1627 the string from the previous specification of that type is used again.
1629 .It Xo Op Ar @ Ns Ar name-list Ns
1632 All messages that contain the given case-insensitive search
1634 ession; if the \*(OPal regular expression (see
1636 support is available
1638 will be interpreted as (an extended) one if any of the
1640 (extended) regular expression characters is seen.
1642 .Ar @ Ns Ar name-list
1643 part is missing, the search is restricted to the subject field body,
1646 specifies a comma-separated list of header fields to search, as in
1648 .Dl '@to,from,cc@Someone i ought to know'
1650 In order to search for a string that includes a
1652 (commercial at) character the
1654 is effectively non-optional, but may be given as the empty string.
1655 Some special header fields may be abbreviated:
1669 respectively and case-insensitively.
1674 can be used to search in (all of) the header(s) of the message, and the
1683 can be used to perform full text searches \(en whereas the former
1684 searches only the body, the latter also searches the message header.
1686 This message specification performs full text comparison, but even with
1687 regular expression support it is almost impossible to write a search
1688 expression that savely matches only a specific address domain.
1689 To request that the content of the header is treated as a list of
1690 addresses, and to strip those down to the plain email address which the
1691 search expression is to be matched against, prefix the header name
1692 (abbreviation) with a tilde
1695 .Dl @~f@@a\e.safe\e.domain\e.match$
1699 .Dq any substring matches
1702 header, which will match addresses (too) even if
1704 is set (and POSIX says
1705 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1708 variable is set, only the local part of the address is evaluated
1709 for the comparison, not ignoring case, and the setting of
1711 is completely ignored.
1712 For finer control and match boundaries use the
1714 search expression; the \*(OPal IMAP-style
1716 expression can also be used if substring matches are desired.
1720 \*(OP IMAP-style SEARCH expressions may also be used.
1721 This addressing mode is available with all types of folders;
1722 \*(UA will perform the search locally as necessary.
1723 Strings must be enclosed by double quotes
1725 in their entirety if they contain white space or parentheses;
1726 within the quotes, only backslash
1728 is recognized as an escape character.
1729 All string searches are case-insensitive.
1730 When the description indicates that the
1732 representation of an address field is used,
1733 this means that the search string is checked against both a list
1736 .Bd -literal -offset indent
1737 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1742 and the addresses without real names from the respective header field.
1743 These search expressions can be nested using parentheses, see below for
1747 .Bl -tag -compact -width ".It Ar _n_u"
1748 .It Ar ( criterion )
1749 All messages that satisfy the given
1751 .It Ar ( criterion1 criterion2 ... criterionN )
1752 All messages that satisfy all of the given criteria.
1754 .It Ar ( or criterion1 criterion2 )
1755 All messages that satisfy either
1760 To connect more than two criteria using
1762 specifications have to be nested using additional parentheses,
1764 .Ql (or a (or b c)) ,
1768 .Ql ((a or b) and c) .
1771 operation of independent criteria on the lowest nesting level,
1772 it is possible to achieve similar effects by using three separate
1776 .It Ar ( not criterion )
1777 All messages that do not satisfy
1779 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1780 All messages that contain
1782 in the envelope representation of the
1785 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1786 All messages that contain
1788 in the envelope representation of the
1791 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1792 All messages that contain
1794 in the envelope representation of the
1797 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1798 All messages that contain
1803 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1804 All messages that contain
1806 in the envelope representation of the
1809 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1810 All messages that contain
1815 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1816 All messages that contain
1819 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1820 All messages that contain
1822 in their header or body.
1823 .It Ar ( larger size )
1824 All messages that are larger than
1827 .It Ar ( smaller size )
1828 All messages that are smaller than
1832 .It Ar ( before date )
1833 All messages that were received before
1835 which must be in the form
1839 denotes the day of the month as one or two digits,
1841 is the name of the month \(en one of
1842 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1845 is the year as four digits, e.g.,
1849 All messages that were received on the specified date.
1850 .It Ar ( since date )
1851 All messages that were received since the specified date.
1852 .It Ar ( sentbefore date )
1853 All messages that were sent on the specified date.
1854 .It Ar ( senton date )
1855 All messages that were sent on the specified date.
1856 .It Ar ( sentsince date )
1857 All messages that were sent since the specified date.
1859 The same criterion as for the previous search.
1860 This specification cannot be used as part of another criterion.
1861 If the previous command line contained more than one independent
1862 criterion then the last of those criteria is used.
1866 .\" .Ss "On URL syntax and credential lookup" {{{
1867 .Ss "On URL syntax and credential lookup"
1869 \*(IN For accessing protocol-specific resources usage of Uniform
1870 Resource Locators (URL, RFC 1738) has become omnipresent.
1871 \*(UA expects and understands URLs in the following form;
1874 denote optional parts, optional either because there also exist other
1875 ways to define the information in question or because support of the
1876 part is protocol-specific (e.g.,
1878 is used by the IMAP protocol but not by POP3);
1883 are specified they must be given in URL percent encoded form (RFC 3986;
1891 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1894 Note that these \*(UA URLs most often don't conform to any real
1895 standard, but instead represent a normalized variant of RFC 1738 \(en
1896 they are not used in data exchange but only ment as a compact,
1897 easy-to-use way of defining and representing information in
1898 a well-known notation.
1901 Many internal variables of \*(UA exist in multiple versions, called
1902 variable chains for the rest of this document: the plain
1907 .Ql variable-USER@HOST .
1914 had been specified in the respective URL, otherwise it refers to the plain
1920 that had been found when doing the user chain lookup as is described
1923 will never be in URL percent encoded form, wether it came from an URL or
1924 not; i.e., values of
1925 .Sx "INTERNAL VARIABLES"
1926 must not be URL percent encoded.
1929 For example, wether an hypothetical URL
1930 .Ql smtp://hey%3Ayou@our.house
1931 had been given that includes a user, or wether the URL was
1932 .Ql smtp://our.house
1933 and the user had been found differently, to lookup the variable chain
1934 .Va smtp-use-starttls
1935 \*(UA first looks for wether
1936 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1937 is defined, then wether
1938 .Ql smtp-\:use-\:starttls-\:our.house
1939 exists before finally ending up looking at the plain variable itself.
1942 \*(UA obeys the following logic scheme when dealing with the
1943 necessary credential informations of an account:
1949 has been given in the URL the variables
1953 are looked up; if no such variable(s) can be found then \*(UA will,
1954 when enforced by the \*(OPal variables
1955 .Va netrc-lookup-HOST
1962 specific entry which provides a
1964 name: this lookup will only succeed if unambiguous (one possible matching
1968 If there is still no
1970 then \*(UA will fall back to the user who is supposed to run \*(UA:
1971 either the name that has been given with the
1973 command line option (or, equivalently, but with less precedence, the
1974 environment variable
1979 The identity of this user has been fixated during \*(UA startup and is
1980 known to be a valid user on the current host.
1983 Authentication: unless otherwise noted this will lookup the
1984 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
1985 variable chain, falling back to a protocol-specific default should this
1991 has been given in the URL, then if the
1993 has been found through the \*(OPal
1995 then that may have already provided the password, too.
1996 Otherwise the variable chain
1997 .Va password-USER@HOST , password-HOST , password
1998 is looked up and used if existent.
2000 \*(OP Then if any of the variables of the chain
2001 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2003 is set the shell command specified therein is run and the output (less
2004 newline characters) will be used as the password.
2005 It is perfectly valid for such an agent to simply not return any data,
2006 in which case the password lookup is continued somewhere else;
2007 Any command failure is treated as a hard error, however.
2009 Afterwards the complete \*(OPal variable chain
2010 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2014 cache is searched for a password only (multiple user accounts for
2015 a single machine may exist as well as a fallback entry without user
2016 but with a password).
2018 If at that point there is still no password available, but the
2019 (protocols') chosen authentication type requires a password, then in
2020 interactive mode the user will be prompted on the terminal.
2025 S/MIME verification works relative to the values found in the
2029 header field(s), which means that the values of
2030 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2032 .Va smime-sign-message-digest
2033 will not be looked up using the
2037 chains from above but instead use the corresponding values from the
2038 message that is being worked on.
2039 In unusual cases multiple and different
2043 combinations may therefore be involved \(en on the other hand those
2044 unusual cases become possible.
2045 The usual case is as short as:
2048 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2049 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2054 contains complete example configurations.
2057 .\" .Ss "Command line editor" {{{
2058 .Ss "Command line editor"
2060 \*(OP \*(UA can be configured to support a command line editor and
2061 command history lists which are saved in between sessions.
2062 One may link against fully-fledged external libraries
2063 .Pf ( Xr readline 6 ,
2065 ) or use \*(UA's own command line editor NCL (Nail-Command-Line)
2066 instead, which should work in all environments which comply to the
2067 ISO C standard (ISO/IEC 9899:1990/Amendment 1:1995).
2068 When an external library is used, interactive behaviour of \*(UA relies
2069 on that library and may not correspond one-to-one to what is described
2073 Regardless of the actually used command line editor
2075 entries will be created for lines entered in command mode only, and
2076 creation of such an entry can be forcefully suppressed by starting the
2077 line with a space character.
2080 handling is by itself an optional feature and may therefore not be
2082 For more information see the documentation of the variables
2086 .Va history-gabby-persist ,
2089 .Va line-editor-disable .
2090 And there is also the \*(OPal
2092 will can be set to cause overall screen resets when \*(UA releases the
2093 terminal in interactive mode.
2096 The builtin \*(UA command line editor supports the following operations;
2099 stands for the combination of the
2101 key plus the mentioned character, e.g.,
2104 .Dq hold down control key and press the A key :
2107 .Bl -tag -compact -width "Ql _M"
2109 Go to the start of the line.
2111 Move the cursor backward one character.
2113 Forward delete the character under the cursor;
2114 quits \*(UA if used on the empty line unless the
2118 Go to the end of the line.
2120 Move the cursor forward one character.
2123 Cancel current operation, full reset.
2124 If there is an active history search or tabulator expansion then this
2125 command will first reset that, reverting to the former line content;
2126 thus a second reset is needed for a full reset in this case.
2127 In all cases \*(UA will reset a possibly used multibyte character input
2133 backward delete one character.
2137 .Dq horizontal tabulator :
2138 try to expand the word before the cursor.
2140 .Dq tabulator-completion
2141 as is known from the
2143 but really means the usual \*(UA expansion, as documented for
2145 yet it involves shell expansion as a last step, too.)
2150 complete this line of input.
2152 Delete all characters from the cursor to the end of the line.
2156 \*(OP Go to the next history entry.
2161 \*(OP Go to the previous history entry.
2163 \*(OP Complete the current line from (the remaining older) history entries.
2170 Delete the characters from the one preceding the cursor to the preceding
2173 Move the cursor forward one word boundary.
2175 Move the cursor backward one word boundary.
2179 If problems with commands that are based upon rightwise movement are
2180 encountered, adjustments of the option
2181 .Va line-editor-cursor-right
2182 may solve the problem, as documented for it.
2185 If the terminal produces key sequences which are compatible with
2187 then the left and right cursor keys will map to
2191 respectively, the up and down cursor keys will map to
2195 and the Home/End/PgUp/PgDown keys will call the
2197 command with the respective arguments
2203 (i.e., perform scrolling through the header summary list).
2206 .\" .Ss "Coloured message display" {{{
2207 .Ss "Coloured message display"
2209 \*(OP \*(UA can be configured to support coloured message display,
2210 realized by emitting ANSI colour escape sequences.
2211 Colours are only used when the
2213 environment variable is set and either the terminal type can be found in
2215 or its name includes the string
2219 On top of what \*(UA knows about the terminal the boolean variable
2221 defines wether these colour sequences are also generated when the output
2222 of a command needs to go through the
2226 ) \(en this is not enabled by default because different pager programs
2227 need different command line switches or other configuration in order to
2228 support those colour sequences, please see the option for more details.
2231 To forcefully disable all colour support, set
2232 .Va colour-disable .
2235 Colours can be configured through font attributes
2256 Multiple specifications can be joined in a comma separated list, as in
2259 .Dl set colour-msginfo="ft=bold,fg=magenta,bg=cyan"
2262 Variables to be set are
2263 .Va colour-msginfo ,
2264 .Va colour-partinfo ,
2268 .Va colour-uheader ,
2270 .Va colour-user-headers ,
2271 which is a list of headers to be colourized via
2273 instead of the default
2276 .\" }}} (DESCRIPTION)
2279 .\" .Sh COMMANDS {{{
2282 Each command is typed on a line by itself,
2283 and may take arguments following the command word.
2284 The command need not be typed in its entirety \(en
2285 the first command which matches the typed prefix is used.
2286 An \(en alphabetically \(en sorted list of commands can be shown
2293 when given an argument, will show a documentation string for the
2294 command matching the expanded argument, as in
2296 which should be a shorthand of
2298 documentation strings are however \*(OPal.
2301 For commands which take message lists as arguments, the next message
2302 forward that satisfies the command's requirements will be used shall no
2303 explicit message list have been specified.
2304 If there are no messages forward of the current message,
2305 the search proceeds backwards,
2306 and if there are no good messages at all,
2308 .Dq no applicable messages
2309 and aborts the command.
2310 The arguments to commands can be quoted, using the following methods:
2313 .Bl -bullet -compact -offset indent
2315 An argument can be enclosed between paired double-quotes
2320 any white space, shell word expansion, or backslash characters (except
2321 as described next) within the quotes are treated literally as part of
2323 A double-quote will be treated literally within single-quotes and vice
2325 Inside such a quoted string the actually used quote character can be
2326 used nonetheless by escaping it with a backslash
2332 An argument that is not enclosed in quotes, as above, can usually still
2333 contain space characters if those spaces are backslash-escaped, as in
2337 A backslash outside of the enclosing quotes is discarded
2338 and the following character is treated literally as part of the argument.
2341 An unquoted backslash at the end of a command line is discarded and the
2342 next line continues the command.
2346 Filenames, where expected, are subsequently subjected to the following
2347 transformations, in sequence:
2350 .Bl -bullet -compact -offset indent
2352 If the filename begins with an unquoted plus sign, and the
2354 variable is defined,
2355 the plus sign will be replaced by the value of the
2357 variable followed by a slash.
2360 variable is unset or is set to null, the filename will be unchanged.
2363 Shell word expansions are applied to the filename.
2364 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2365 .Sy Compatibility note:
2366 on the long run support for complete shell word expansion will be
2367 replaced by an internally implemented restricted expansion mechanism in
2368 order to circumvent possible security impacts through shell expansion.
2369 Expect that a growing number of program parts only support this
2372 Meta expansions are applied to the filename: leading tilde characters
2374 will be replaced by the expansion of
2376 and any occurrence of
2380 will be replaced by the expansion of the variable, if possible;
2381 \*(UA internal as well as environmental (shell) variables can be
2382 accessed through this mechanism.
2383 In order to include a raw
2385 character precede it with a backslash
2387 to include a backslash double it.
2388 If more than a single pathname results from this expansion and the
2389 command is expecting one file, an error results.
2391 Note that in interactive display context, in order to allow simple
2392 value acceptance (typing
2394 backslash quoting is performed automatically as necessary, e.g., a file
2395 .Ql diet\e is \ecurd.txt
2396 will be displayed as
2397 .Ql diet\e\e is \e\ecurd.txt .
2401 The following commands are available:
2403 .Bl -tag -width ".Ic _ccount"
2410 ) command which follows.
2414 The comment-command causes the entire line to be ignored.
2416 this really is a normal command which' purpose is to discard its
2419 indicating special character, which means that, e.g., trailing comments
2420 on a line are not possible.
2424 Goes to the next message in sequence and types it
2430 Print out the preceding message.
2431 If given a numeric argument n,
2432 goes to the n'th previous message and prints it.
2436 Show the current message number (the
2441 Prints a brief summary of commands.
2442 \*(OP Given an argument a synopsis for the command in question is
2444 commands can be abbreviated in general and this command can be used
2445 to see the full expansion of an abbreviation including the synopsis,
2451 and see how the display changes.
2461 Interprets the remainder of the word as a macro name and passes it
2466 is a shorter synonym for
2467 .Ql call Ar mymacro .
2471 (ac) Creates, selects or lists (an) account(s).
2472 An account is a group of commands and variable settings which together
2473 usually arrange the environment for the purpose of creating a system login.
2474 Without any argument a listing of all defined accounts and their content
2476 A specific account can be activated by giving solely its name, resulting
2477 in the system mailbox or inbox of that account to be activated as via an
2478 explicit use of the command
2480 The two argument form is identical to defining a macro as via
2483 .Bd -literal -offset indent
2485 set folder=imaps://mylogin@imap.myisp.example
2487 set from="myname@myisp.example (My Name)"
2488 set smtp=smtp://mylogin@smtp.myisp.example
2492 creates an account named
2494 which can later be selected by specifying
2498 (case-insensitive) always exists.
2500 can be used to localize account settings \(en different to normal macros
2501 the settings will be reverted once the account is switched off.
2502 Accounts can be deleted via
2507 (a) With no arguments, prints out all currently-defined aliases.
2508 With one argument, prints out that alias.
2509 With more than one argument,
2510 creates a new alias or appends to an existing one.
2512 can be used to delete aliases.
2516 (alt) Manage a list of alternate addresses / names of the active user,
2517 members of which will be removed from recipient lists when replying to
2520 variable is not set).
2521 If arguments are given the set of alternate names is replaced by them,
2522 without arguments the current set is displayed.
2526 Takes a message list and marks each message as having been answered.
2527 This mark has no technical meaning in the mail system;
2528 it just causes messages to be marked in the header summary,
2529 and makes them specially addressable.
2533 \*(OP\*(OB Only applicable to cached IMAP mailboxes;
2534 takes a message list and reads the specified messages into the IMAP
2539 Calls a macro that has been created via
2544 (ch) Change the working directory to
2546 or the given argument.
2552 \*(OP Only applicable to S/MIME signed messages.
2553 Takes a message list and a file name and saves the certificates
2554 contained within the message signatures to the named file in both
2555 human-readable and PEM format.
2556 The certificates can later be used to send encrypted messages to the
2557 respective message senders by setting
2558 .Va smime-encrypt-USER@HOST
2563 (ch) Change the working directory to
2565 or the given argument.
2571 Only applicable to threaded mode.
2572 Takes a message list and makes all replies to these messages invisible
2573 in header summaries, unless they are in state
2578 \*(OP\*(OB If operating in disconnected mode on an IMAP mailbox,
2579 switch to online mode and connect to the mail server while retaining
2581 See the description of the
2583 variable for more information.
2587 (C) Copy messages to files whose names are derived from the author of
2588 the respective message and don't mark them as being saved;
2589 otherwise identical to
2594 (c) Copy messages to the named file and don't mark them as being saved;
2595 otherwise identical to
2600 Print the current working directory.
2604 \*(OP For unencrypted messages this command is identical to
2606 Encrypted messages are first decrypted, if possible, and then copied.
2610 \*(OP For unencrypted messages this command is identical to
2612 Encrypted messages are first decrypted, if possible, and then copied.
2616 Without arguments the current list of macros, including their content,
2617 is printed, otherwise a macro is defined.
2618 A macro definition is a sequence of commands in the following form:
2619 .Bd -literal -offset indent
2628 A defined macro can be invoked explicitly by using the
2632 commands, or implicitly by setting the
2635 .Va folder-hook-FOLDER
2637 Note that interpretation of
2639 depends on how (i.e.,
2641 normal macro, folder hook, account switch) the macro is invoked.
2642 Macros can be deleted via
2644 .Bd -filled -compact -offset indent
2646 Macro behaviour, including option localization, will change in v15.
2647 To be on the absolutely safe side and avoid any surprises it may be wise
2648 to use wrappers that depend on the program version, e.g.,:
2650 .Bd -literal -offset indent
2651 if $version-major < 15
2657 echo "Please reverify macro name (post v15)"
2664 (d) Marks the given message list as
2666 Deleted messages will neither be saved in
2668 nor will they be available for most other commands.
2679 \*(OP\*(OB (disco) If operating in online mode on an IMAP mailbox,
2680 switch to disconnected mode while retaining the mailbox status.
2681 See the description of the
2684 A list of messages may optionally be given as argument;
2685 the respective messages are then read into the cache before the
2686 connection is closed.
2687 Thus `disco *' makes the entire mailbox available for disconnected use.
2692 Deletes the current message and prints the next message.
2693 If there is no next message, \*(UA says
2698 Takes a message list and marks each given message as a draft.
2699 This mark has no technical meaning in the mail system;
2700 it just causes messages to be marked in the header summary,
2701 and makes them specially addressable.
2705 (ec) Echoes its arguments,
2706 resolving special names as documented for the command
2708 The escape sequences
2720 are interpreted just as they are by
2722 (proper quoting provided).
2726 (e) Point the text editor (as defined in
2728 at each message from the given list in turn.
2729 Modified contents are discarded unless the
2736 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2737 conditional \(em if the condition of a preceeding
2739 was false, check the following condition and execute the following block
2740 if it evaluates true.
2745 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2746 conditional \(em if none of the conditions of the preceeding
2750 commands was true, the
2756 (en) Marks the end of an
2757 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2758 conditional execution block.
2762 \*(OP Since \*(UA uses the console as a user interface it can happen
2763 that messages scroll by too fast to become recognized.
2764 Optionally an error message ring queue is available which stores
2765 duplicates of any error message and notifies the user in interactive
2766 sessions whenever a new error has occurred.
2767 The queue is finite: if its maximum size is reached any new message
2768 replaces the eldest.
2771 can be used to manage this message queue: if given
2773 or no argument the queue will be displayed and cleared,
2775 will only clear all messages from the queue.
2779 (ex or x) Exit from \*(UA without changing the active mailbox and skip
2780 any saving of messages in
2782 as well as a possibly tracked command line editor history file.
2786 Show the list of features that have been compiled into \*(UA.
2787 (Outputs the contents of the variable
2794 but open the mailbox readonly.
2798 (fi) The file command switches to a new mailbox.
2799 Without arguments it prints the complete state of the current mailbox.
2800 If an argument is given, it will write out changes (such as deletions)
2801 the user has made and open a new mailbox.
2802 Some special conventions are recognized for the
2806 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
2808 (number sign) means the previous file,
2810 (percent sign) means the invoking user's system mailbox
2815 means the system mailbox of
2817 (and never the value of
2819 regardless of its actual setting),
2821 (ampersand) means the invoking user's
2831 expands to the same value as
2833 but the file is handled as a system mailbox by, e.g., the
2837 commands, meaning that messages that have been read in the current
2838 session will be moved to the
2840 mailbox instead of simply being flagged as read.
2843 If the name matches one of the strings defined with the command
2845 it is replaced by its long form and expanded.
2846 If the name ends with
2851 it is treated as being compressed with
2856 respectively, and transparently handled through an intermediate
2857 (un)compression step (using a temporary file) with the according
2858 facility, sufficient support provided.
2859 Likewise, if the named file doesn't exist, but a file with one of the
2860 mentioned compression extensions does, then the name is automatically
2861 expanded and the compressed file is used.
2863 Otherwise, if the name ends with an extension for which
2864 .Va file-hook-load-EXTENSION
2866 .Va file-hook-save-EXTENSION
2867 variables are set, then the given hooks will be used to load and save
2869 and \*(UA will work with an intermediate temporary file.
2871 MBOX files (flat file-based mailboxes) are generally locked during file
2872 operations in order to avoid inconsistencies due to concurrent
2874 \*(OPal Mailbox files which \*(UA treats as system or primary mailboxes
2875 will also be protected by so-called dotlock files, the traditional way
2876 of mail spool file locking: for any file
2880 will be created for the duration of the synchronization \(em
2881 as necessary a privilege-separated dotlock child process will be used
2882 to accommodate for necessary privilege adjustments in order to create
2883 the dotlock file in the same directory
2884 and with the same user and group identities as the file of interest.
2887 for fine-tuning the handling of MBOX files.
2891 refers to a directory with the subdirectories
2896 then it is treated as a folder in
2901 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
2902 .Dl \*(OU protocol://[user@]host[:port][/path]
2904 is taken as an Internet mailbox specification.
2905 The \*(OPally supported protocols are
2909 (POP3 with SSL/TLS encrypted transport).
2912 part is valid only for IMAP; there it defaults to
2914 Also see the section
2915 .Sx "On URL syntax and credential lookup" .
2919 contains special characters, in particular
2923 they must be escaped in URL notation \(en the command
2925 can be used to show the necessary conversion.
2926 The optional `path' part applies to IMAP only;
2927 if it is omitted, the default `INBOX' is used.
2929 If \*(UA is connected to an IMAP server,
2930 a name of the form `@mailbox' refers to the `mailbox' on that server,
2931 but otherwise a `@' prefix has no special meaning.
2935 Takes a message list and marks the messages as
2937 ged for urgent/special attention.
2938 This mark has no technical meaning in the mail system;
2939 it just causes messages to be highlighted in the header summary,
2940 and makes them specially addressable.
2949 With no arguments, list the names of the folders in the folder directory.
2950 With an existing folder as an argument,
2951 lists the names of folders below the named folder;
2952 e.\|g. the command `folders @' lists the folders on the base level of
2953 the current IMAP server.
2954 See also the variable
2955 .Va imap-list-depth .
2961 but saves the message in a file named after the local part of the first
2962 recipient's address (instead of in
2969 but saves the message in a file named after the local part of the first
2970 recipient's address (instead of in
2977 but responds to all recipients regardless of the
2982 .It Ic followupsender
2985 but responds to the sender only regardless of the
3001 (f) Takes a list of messages and prints their message headers
3002 (which qualifies this command as \*(UAs search facility).
3008 but saves the message in a file named after the local part of the
3009 recipient's address (instead of in
3014 Takes a message and the address of a recipient
3015 and forwards the message to him.
3016 The text of the original message is included in the new one,
3017 with the value of the
3019 variable printed before.
3024 commands specify which header fields are included in the new message.
3025 Only the first part of a multipart message is included unless the
3026 .Va forward-as-attachment
3030 is set recipient addresses will be stripped from comments, names etc.
3034 Specifies which header fields are to be ignored with the command
3036 This command has no effect when the
3037 .Va forward-as-attachment
3042 Specifies which header fields are to be retained with the command
3047 This command has no effect when the
3048 .Va forward-as-attachment
3053 Define or list command aliases, so-called ghosts.
3054 Without arguments a list of all currently known aliases is printed.
3055 With one argument the expansion of the given alias is shown.
3056 With two or more arguments a command alias is defined or updated: the
3057 first argument is the name under which the remaining command line should
3058 be accessible, the content of which can be just about anything.
3059 A ghost can be used everywhere a normal command can be used, but always
3060 takes precedence; any arguments that are given to the command alias are
3061 joined onto the alias content, and the resulting string forms the
3062 command line that is, in effect, executed.
3065 .Bd -literal -offset indent
3067 `ghost': no such alias: "xx"
3070 ghost xx "echo hello,"
3079 (h) Show the current group of headers, the size of which depends on
3082 and the style of which can be adjusted with the variable
3084 If a message-specification is given the group of headers containing the
3085 first message therein is shown and the message at the top of the screen
3100 the list of history entries;
3103 argument selects and shows the respective history entry \(en
3106 to accept it, and the history entry will become the new history top.
3107 The default mode if no arguments are given is
3114 Takes a message list and marks each message therein to be saved in the
3115 user's system mailbox instead of in
3117 Does not override the
3120 \*(UA deviates from the POSIX standard with this command, because a
3122 command issued after
3124 will display the following message, not the current one.
3129 (i) Part of the nestable
3130 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3131 conditional execution construct \(em if the given condition is true then
3132 the encapsulated block is executed.
3133 POSIX only supports the (case-insensitive) conditions
3138 end, all remaining conditions are non-portable extensions; note that
3139 falsely specified conditions cause the execution of the entire
3140 conditional construct until the (matching) closing
3142 command to be suppressed.
3143 The syntax of the nestable
3145 conditional execution construct requires that each condition and syntax
3146 element is surrounded by whitespace.
3148 .Bd -literal -offset indent
3157 The (case-insensitive) condition
3159 erminal will evaluate to true if the standard input is a terminal, i.e.,
3160 in interactive sessions.
3161 Another condition can be any boolean value (see the section
3162 .Sx "INTERNAL VARIABLES"
3163 for textual boolean representations) to mark an enwrapped block as
3166 .Dq always execute .
3167 It is possible to check a variable for existence or compare its
3168 expansion against a user given value or another variable via the
3170 .Pf ( Dq variable next )
3171 conditional trigger character.
3172 The available comparison operators are
3176 (less than or equal to),
3182 (greater than or equal to),
3186 (is substring of) and
3188 (is not substring of).
3189 The values of the left and right hand side are treated as strings and
3190 are compared 8-bit byte-wise, ignoring case according to the rules of
3191 the US-ASCII encoding (therefore, dependend on the active locale,
3192 possibly producing false results for strings in the locale encoding).
3193 Except for the substring checks the comparison will instead be performed
3194 arithmetically if both, the user given value as well as the variable
3195 content, can be parsed as numbers (integers).
3196 An unset variable is treated as the empty string.
3199 When the \*(OPal regular expression support is available, the additional
3205 They treat the right hand side as an extended regular expression that is
3206 matched case-insensitively and according to the active
3208 locale, meaning that strings in the locale encoding should be matched
3212 Conditions can be joined via AND-OR lists (where the AND operator is
3214 and the OR operator is
3216 which have equal precedence and will be evaluated with left
3217 associativity, thus using the same syntax that is known for the
3219 It is also possible to form groups of conditions and lists by enclosing
3220 them in pairs of brackets
3221 .Ql [\ \&.\&.\&.\ ] ,
3222 which may be interlocked within each other, and also be joined via
3226 The results of individual conditions and entire groups may be modified
3227 via unary operators: the unary operator
3229 will reverse the result.
3231 .Bd -literal -offset indent
3235 if $ttycharset == "UTF-8"
3236 echo *ttycharset* is set to UTF-8, case-insensitively
3240 echo These two variables are equal
3242 if $version-major >= 15
3243 echo Running a new version..
3244 if $features =@ "regex"
3245 if $TERM =~ "^xterm\&.*"
3246 echo ..in an X terminal
3249 if [ [ true ] && [ [ $debug ] || [ $verbose ] ] ]
3252 if true && $debug || $verbose
3253 echo Left associativity, as is known from the shell
3255 if ! ! true && ! [ ! $debug && ! $verbose ]
3256 echo Unary operator support
3264 Without arguments the list of ignored header fields is printed,
3265 otherwise the given list of header fields is added to the ignore list:
3266 Header fields in the ignore list are not printed on the terminal when
3267 a message is printed.
3268 To print a message in its entirety, use the commands
3279 \*(OP\*(OB Sends command strings directly to the current IMAP server.
3280 \*(UA operates always in IMAP `selected state' on the current mailbox;
3281 commands that change this will produce undesirable results and should be
3283 Useful IMAP commands are:
3284 .Bl -tag -offset indent -width ".Ic getquotearoot"
3286 Takes the name of an IMAP mailbox as an argument and creates it.
3288 (RFC 2087) Takes the name of an IMAP mailbox as an argument
3289 and prints the quotas that apply to the mailbox.
3290 Not all IMAP servers support this command.
3292 (RFC 2342) Takes no arguments and prints the Personal Namespaces,
3293 the Other User's Namespaces and the Shared Namespaces.
3294 Each namespace type is printed in parentheses;
3295 if there are multiple namespaces of the same type,
3296 inner parentheses separate them.
3297 For each namespace a prefix and a hierarchy separator is listed.
3298 Not all IMAP servers support this command.
3303 Prints the names of all available commands, alphabetically sorted.
3307 This command can be used to localize changes to variables, meaning that
3308 their state will be reverted to the former one once the covered scope
3310 It can only be used inside of macro definition blocks introduced by
3314 and is interpreted as a boolean (string, see
3315 .Sx "INTERNAL VARIABLES" ) ;
3318 of an account is left once it is switched off again.
3319 .Bd -literal -offset indent
3320 define temporary_settings {
3335 enables change localization and calls
3337 which explicitly resets localization, then any value changes within
3339 will still be reverted by
3344 Reply to messages that come in via known
3347 .Pf ( Ic mlsubscribe )
3348 mailing lists, or pretend to do so (see
3349 .Sx "Mailing lists" ) :
3352 functionality this will actively resort and even remove message
3353 recipients in order to generate a message that is supposed to be send to
3355 For example it will also implicitly generate a
3356 .Ql Mail-Followup-To:
3357 header if that seems useful, regardless of the setting of the variable
3364 but saves the message in a file named after the local part of the first
3365 recipient's address (instead of in
3370 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3371 or asks on standard input if none were given;
3372 then collects the remaining mail content and sends it out.
3376 (mb) The given message list is to be sent to
3378 when \*(UA is quit; this is the default action unless the
3381 \*(ID This command can only be used in a system mailbox (see
3386 Without any arguments the content of the MIME type cache will displayed.
3387 Otherwise each argument defines a complete MIME type specification of
3388 a type that shall be added (prepended) to the cache.
3389 In any event MIME type sources are loaded first as necessary \(en
3390 .Va mimetypes-load-control
3391 can be used to fine-tune which sources are actually loaded.
3392 Refer to the section on
3393 .Sx "The mime.types files"
3394 for more on MIME type specifications and this topic in general.
3395 MIME type unregistration and cache resets can be triggered with
3400 Without arguments the list of all currently defined mailing lists
3401 (and their attributes, if any) is printed.
3402 Otherwise all given arguments (which need not be quoted except for
3403 whitespace) will be added and henceforth be recognized as mailing lists.
3404 Mailing lists may be removed via the command
3407 If the \*(OPal regular expression support is available then mailing
3408 lists may also be specified as (extended) regular expressions (see
3414 Without arguments the list of all currently defined mailing lists which
3415 have a subscription attribute is printed.
3416 Otherwise this attribute will be set for all given mailing lists,
3417 newly creating them as necessary (as via
3419 Subscription attributes may be removed via the command
3428 but moves the messages to a file named after the local part of the
3429 sender address of the first message (instead of in
3436 but marks the messages for deletion if they were transferred
3443 but also prints ignored header fields and all MIME parts.
3451 on the given messages, even in non-interactive mode and as long as the
3452 standard output is a terminal.
3458 \*(OP When used without arguments or if
3460 has been given the content of the
3462 cache is printed, loading it first as necessary,
3465 then the cache will only be initialized and
3467 will remove its contents.
3468 Note that \*(UA will try to load the file only once, use
3469 .Ql Ic netrc Ns \:\0\:clear
3470 to unlock further attempts.
3474 .Sx "On URL syntax and credential lookup" ;
3476 .Sx "The .netrc file"
3477 documents the file format in detail.
3481 Checks for new mail in the current folder without committing any changes
3483 If new mail is present, a message is printed.
3487 the headers of each new message are also printed.
3495 Goes to the next message in sequence and types it.
3496 With an argument list, types the next matching message.
3510 If the current folder is accessed via a network connection, a
3512 command is sent, otherwise no operation is performed.
3518 but also prints ignored header fields and all MIME parts.
3526 on the given messages, even in non-interactive mode and as long as the
3527 standard output is a terminal.
3535 but also pipes ignored header fields and all parts of MIME
3536 .Ql multipart/alternative
3541 (pi) Takes a message list and a shell command
3542 and pipes the messages through the command.
3543 Without an argument the current message is piped through the command
3550 every message is followed by a formfeed character.
3571 (q) Terminates the session, saving all undeleted, unsaved messages in
3574 preserving all messages marked with
3578 or never referenced in the system mailbox,
3579 and removing all other messages from the system mailbox.
3580 If new mail has arrived during the session,
3582 .Dq You have new mail
3584 If given while editing a mailbox file with the command line flag
3586 then the edit file is rewritten.
3587 A return to the shell is effected,
3588 unless the rewrite of edit file fails,
3589 in which case the user can escape with the exit command.
3603 Removes the named folders.
3604 The user is asked for confirmation in interactive mode.
3608 Takes the name of an existing folder
3609 and the name for the new folder
3610 and renames the first to the second one.
3611 Both folders must be of the same type
3612 and must be located on the current server for IMAP.
3616 (R) Reply to originator.
3617 Does not reply to other recipients of the original message.
3619 will exchange this command with
3623 is set the recipient address will be stripped from comments, names etc.
3627 (r) Take a message and group-responds to it by addressing the sender
3630 .Va followup-to-honour ,
3633 .Va recipients-in-cc
3634 influence response behaviour.
3637 offers special support for replying to mailing lists.
3640 is set recipient addresses will be stripped from comments, names etc.
3653 but initiates a group-reply regardless of the value of
3660 but responds to the sender only regardless of the value of
3667 but does not add any header lines.
3668 This is not a way to hide the sender's identity,
3669 but useful for sending a message again to the same recipients.
3673 Takes a list of messages and a user name
3674 and sends each message to the named user.
3676 and related header fields are prepended to the new copy of the message.
3694 .It Ic respondsender
3700 (ret) Without arguments the list of retained header fields is printed,
3701 otherwise the given list of header fields is added to the retain list:
3702 Header fields in the retain list are shown on the terminal when
3703 a message is printed, all other header fields are suppressed.
3704 To print a message in its entirety, use the commands
3713 takes precedence over the mentioned.
3719 but saves the messages in a file named after the local part of the
3720 sender of the first message instead of (in
3722 and) taking a filename argument.
3726 (s) Takes a message list and a filename and appends each message in turn
3727 to the end of the file.
3728 If no filename is given, the
3731 The filename in quotes, followed by the generated character count
3732 is echoed on the user's terminal.
3733 If editing a system mailbox the messages are marked for deletion.
3734 Filename interpretation as described for the
3736 command is performed.
3753 Header fields thus marked are filtered out when saving a message by
3755 or when automatically saving to
3757 This command should only be applied to header fields that do not contain
3758 information needed to decode the message,
3759 as MIME content fields do.
3760 If saving messages on an IMAP account ignoring fields makes it
3761 impossible to copy the data directly on the server,
3762 thus operation usually becomes much slower.
3774 Header fields thus marked are the only ones saved with a message when
3777 or when automatically saving to
3782 The use of this command is strongly discouraged since it may strip
3783 header fields that are needed to decode the message correctly.
3787 Takes a message list and marks all messages as having been read.
3791 (se) Without arguments this command prints all variables and their
3792 values which are currently known to \*(UA.
3793 Setting any of the variables
3797 changes the output format to BSD style, otherwise a properly quoted
3798 listing is produced.
3803 has been set twice then the listing is modified to mark out assembled
3806 Otherwise modifies (set and unsets) the given variables.
3807 Arguments are of the form
3809 (no space before or after
3813 if there is no value.
3814 Quotation marks may be placed around any part of the assignment
3815 statement to quote blanks or tabs, e.g.,
3817 .Dl set indentprefix="->"
3819 If an argument begins with
3823 the effect is the same as invoking the
3825 command with the remaining part of the variable
3826 .Pf ( Ql unset save ) .
3832 except that the variables are also exported into the program environment;
3833 since this task requires native host support the command will always
3834 report error if that is not available (but still act like
3837 This operation is a no-op unless all resource files have been loaded.
3843 (sh) Invokes an interactive version of the shell.
3847 Without arguments the list of all currently defined shortcuts is
3849 Otherwise all given arguments (which need not be quoted except for
3850 whitespace) are treated as pairs of shortcuts and their expansions,
3851 creating new or changing already existing shortcuts, as necessary.
3852 Shortcuts may be removed via the command
3854 The expansion strings should be in the syntax that has been described
3863 but performs neither MIME decoding nor decryption, so that the raw
3864 message text is shown.
3868 (si) Print the size in characters of each message of the given
3873 Shows the current sorting criterion when used without an argument.
3874 Otherwise creates a sorted representation of the current folder,
3877 command and the addressing modes such that they refer to messages in
3879 Message numbers are the same as in regular mode.
3883 a header summary in the new order is also displayed.
3884 Automatic folder sorting can be enabled by setting the
3886 variable, as in, e.g.,
3887 .Ql set autosort=thread .
3888 Possible sorting criterions are:
3890 .Bl -tag -compact -offset indent -width "subject"
3892 Sort the messages by their
3894 field, that is by the time they were sent.
3896 Sort messages by the value of their
3898 field, that is by the address of the sender.
3901 variable is set, the sender's real name (if any) is used.
3903 Sort the messages by their size.
3905 \*(OP Sort the message by their spam score, as has been classified by
3908 Sort the messages by their message status.
3910 Sort the messages by their subject.
3912 Create a threaded display.
3914 Sort messages by the value of their
3916 field, that is by the address of the recipient.
3919 variable is set, the recipient's real name (if any) is used.
3924 (so) The source command reads commands from a file.
3930 is that this command will not generate an error if the given file
3931 argument cannot be opened successfully.
3932 This can matter in, e.g., resource files, since loading of those is
3933 stopped when an error is encountered.
3937 \*(OP Takes a list of messages and clears their
3943 \*(OP Takes a list of messages and causes the
3945 to forget it has ever used them to train its Bayesian filter.
3946 Unless otherwise noted the
3948 flag of the message is inspected to chose wether a message shall be
3956 \*(OP Takes a list of messages and informs the Bayesian filter of the
3960 This also clears the
3962 flag of the messages in question.
3966 \*(OP Takes a list of messages and rates them using the configured
3967 .Va spam-interface ,
3968 without modifying the messages, but setting their
3970 flag as appropriate; because the spam rating headers are lost the rate
3971 will be forgotten once the mailbox is left.
3972 Refer to the manual section
3974 for the complete picture of spam handling in \*(UA.
3978 \*(OP Takes a list of messages and sets their
3984 \*(OP Takes a list of messages and informs the Bayesian filter of the
3990 flag of the messages in question.
3999 Create a threaded representation of the current folder,
4000 i.\|e. indent messages that are replies to other messages in the header
4001 display and change the
4003 command and the addressing modes such that they refer to messages in the
4005 Message numbers are the same as in unthreaded mode.
4009 a header summary in threaded order is also printed.
4013 (to) Takes a message list and prints the top few lines of each.
4014 The number of lines printed is controlled by the variable
4016 and defaults to five.
4020 (tou) Takes a message list and marks the messages for saving in
4022 \*(UA deviates from the POSIX standard with this command,
4025 command will display the following message instead of the current one.
4031 but also prints out ignored header fields and all parts of MIME
4032 .Ql multipart/alternative
4037 (t) Takes a message list and types out each message on the user's
4043 For MIME multipart messages, all parts with a content type of
4047 are shown, the other are hidden except for their headers.
4048 Messages are decrypted and converted to the terminal character set
4053 Delete all given accounts.
4054 An error message is printed if a given account is not defined.
4057 will discard all existing accounts.
4061 (una) Takes a list of names defined by alias commands
4062 and discards the remembered groups of users.
4065 will discard all existing aliases.
4069 Takes a message list and marks each message as not having been answered.
4073 Only applicable to threaded mode.
4074 Takes a message list and makes the message and all replies to it visible
4075 in header summaries again.
4076 When a message becomes the current message,
4077 it is automatically made visible.
4078 Also when a message with collapsed replies is printed,
4079 all of these are automatically uncollapsed.
4083 Undefine all given macros.
4084 An error message is printed if a given macro is not defined.
4087 will discard all existing macros.
4091 (u) Takes a message list and marks each message as not being deleted.
4095 Takes a message list and
4101 Takes a message list and marks each message as not being
4106 Removes the header field names from the list of ignored fields for the
4111 will remove all fields.
4115 Removes the header field names from the list of retained fields for the
4120 will remove all fields.
4124 Remove all the given command
4128 will remove all ghosts.
4132 Removes the header field names from the list of ignored fields.
4135 will remove all fields.
4139 Delete all given MIME types, e.g.,
4140 .Ql unmimetype text/plain
4141 will remove all registered specifications for the MIME type
4145 will discard all existing MIME types, just as will
4147 but which also reenables cache initialization via
4148 .Va mimetypes-load-control .
4152 Forget about all the given mailing lists.
4155 will remove all lists.
4160 .It Ic unmlsubscribe
4161 Remove the subscription attribute from all given mailing lists.
4164 will clear the attribute from all lists which have it set.
4175 Takes a message list and marks each message as not having been read.
4179 Removes the header field names from the list of retained fields.
4182 will remove all fields.
4186 Removes the header field names from the list of ignored fields for
4190 will remove all fields.
4194 Removes the header field names from the list of retained fields for
4198 will remove all fields.
4202 (uns) Takes a list of option names and discards their remembered values;
4210 except that the variables are also removed from the program environment;
4211 since this task requires native host support the command will always
4212 report error if that is not available (but still act like
4215 This operation is a no-op unless all resource files have been loaded.
4221 Deletes the shortcut names given as arguments.
4224 will remove all shortcuts.
4228 Disable sorted or threaded mode
4234 return to normal message order and,
4238 print a header summary.
4248 Decode the given URL-encoded string arguments and show the results.
4249 Note the resulting strings may not be valid in the current locale, see
4254 URL-encode the given arguments and show the results.
4255 Because the arguments effectively are in the character set of the
4256 current locale the results will vary accordingly unless the input solely
4257 consists of characters in the portable character set, see
4258 .Sx "Character sets" .
4262 Edit the values of or create the given variable(s) in the
4264 Boolean variables cannot be edited.
4268 Show informations about all the given variables.
4269 \*(UA knows about a finite set of known builtin variables that are
4270 subdivided further in boolean and value variants;
4271 they may have special properties, like
4273 (setting may not be changed) and
4275 meaning that the value is generated on-the-fly as necessary.
4276 Beside those known variables an infinite number of unknown, so-called
4278 variables, which are expected to be able to store values, may exist.
4279 .Bd -literal -offset indent
4281 ? varshow sendwait version-major foo bar
4282 "sendwait": (73) boolean: set=1 (ENVIRON=0)
4283 "version-major": (192) value, read-only, virtual:\e
4284 set=1 (ENVIRON=0) value<14>
4285 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4286 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4291 \*(OP Takes a message list and verifies each message.
4292 If a message is not a S/MIME signed message,
4293 verification will fail for it.
4294 The verification process checks if the message was signed using a valid
4296 if the message sender's email address matches one of those contained
4297 within the certificate,
4298 and if the message content has been altered.
4302 (v) Takes a message list and invokes the display editor on each message.
4303 Modified contents are discarded unless the
4309 (w) For conventional messages the body without all headers is written.
4310 The output is decrypted and converted to its native format as necessary.
4311 If the output file exists, the text is appended.
4312 If a message is in MIME multipart format its first part is written to
4313 the specified file as for conventional messages,
4314 and the user is asked for a filename to save each other part.
4315 For convience saving of each part may be skipped by giving an empty value;
4316 the same result can also be achieved by writing it to
4318 For the second and subsequent parts a leading
4320 character causes the part to be piped to the remainder of the user input
4321 interpreted as a shell command;
4322 otherwise the user input is expanded as usually for folders,
4323 e.g., tilde expansion is performed.
4324 In non-interactive mode, only the parts of the multipart message
4325 that have a filename given in the part header are written,
4326 the others are discarded.
4327 The original message is never marked for deletion in the originating
4330 the contents of the destination file are overwritten if the file
4332 No special handling of compressed files is performed.
4341 \*(UA presents message headers in windowfuls as described under the
4344 This command scrolls to the next window of messages.
4345 If an argument is given,
4346 it specifies the window to use.
4347 A number prefixed by
4351 indicates that the window is calculated in relation to the current position.
4352 A number without a prefix specifies an absolute window number,
4355 lets \*(UA scroll to the last window of messages.
4361 but scrolls to the next or previous window that contains at least one
4370 .\" .Sh TILDE ESCAPES {{{
4373 Here is a summary of the tilde escapes,
4374 which are used to perform special functions when composing messages.
4375 Tilde escapes are only recognized at the beginning of lines.
4378 is somewhat of a misnomer since the actual escape character can be
4379 changed by adjusting the option
4382 .Bl -tag -width ".Ic __ filename"
4385 Insert the string of text in the message prefaced by a single
4387 (If the escape character has been changed,
4388 that character must be doubled
4389 in order to send it at the beginning of a line.)
4392 .It Ic ~! Ar command
4393 Execute the indicated shell
4395 then return to the message.
4399 Same effect as typing the end-of-file character.
4402 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4403 Execute the given \*(UA command.
4404 Not all commands, however, are allowed.
4408 Write a summary of command escapes.
4411 .It Ic ~< Ar filename
4416 .It Ic ~<! Ar command
4418 is executed using the shell.
4419 Its standard output is inserted into the message.
4422 .It Ic ~@ Op Ar filename...
4423 With no arguments, edit the attachment list interactively.
4424 If an attachment's file name is left empty,
4425 that attachment is deleted from the list.
4426 When the end of the attachment list is reached,
4427 \*(UA will ask for further attachments until an empty name is given.
4428 If a given file name solely consists of the number sign
4430 followed by a valid message number of the currently active mailbox, then
4431 the given message is attached as a MIME
4433 and the rest of this section does not apply.
4435 If character set conversion has been compiled into \*(UA, then this mode
4436 gives the user the option to specify input and output character sets,
4437 unless the file extension indicates binary content, in which case \*(UA
4438 asks wether this step shall be skipped for the attachment in question.
4439 If not skipped, then the charset that succeeds to represent the
4440 attachment data will be used in the
4442 MIME parameter of the mail message:
4444 .Bl -bullet -compact
4446 If input and output character sets are specified, then the conversion is
4447 performed on the fly.
4448 The user will be asked repeatedly until the desired conversion succeeds.
4450 If only an output character set is specified, then the input is assumed
4453 charset and will be converted to the given output charset on the fly.
4454 The user will be asked repeatedly until the desired conversion succeeds.
4456 If no character sets are specified at all then the algorithm that is
4457 documented in the section
4458 .Sx "Character sets"
4459 is applied, but directly and on the fly.
4460 The user will be asked repeatedly until the desired conversion succeeds.
4462 Finally, if an input-, but no output character set is specified, then no
4463 conversion is ever performed, but the
4465 MIME parameter value will still be set to the user input.
4467 The character set selection loop can be left by typing
4469 i.e., causing an interrupt.
4470 .\" \*(OU next sentence
4471 Note that before \*(UA version 15.0 this terminates the entire
4472 current attachment selection, not only the character set selection.
4475 Without character set conversion support, \*(UA will ask for the input
4476 character set only, and it'll set the
4478 MIME parameter value to the given input, if any;
4479 if no user input is seen then the
4481 character set will be used for the parameter value instead.
4482 Note that the file extension check isn't performed in this mode, since
4483 no conversion will take place anyway.
4485 Note that in non-interactive mode, for reproduceabilities sake, there
4486 will always be two questions for each attachment, regardless of wether
4487 character set conversion is available and what the file extension is.
4488 The first asks for the filename, and the second asks for the input
4489 character set to be passed through to the corresponding MIME parameter;
4490 no conversion will be tried if there is input to the latter question,
4491 otherwise the usual conversion algorithm, as above, is applied.
4492 For message attachments, the answer to the second question is completely
4497 arguments are specified for the
4499 command they are treated as a comma separated list of files,
4500 which are all expanded and appended to the end of the attachment list.
4501 (Filenames with commas, or with leading or trailing whitespace can only
4502 be added via the command line or the first method.
4503 Message attachments can only be added via the first method;
4504 filenames which clash with message numbers can only be added via the
4505 command line or the second method.)
4506 In this mode the (text) attachments are assumed to be in
4508 encoding, and will be evaluated as documented in the section
4509 .Sx "Character sets" .
4513 Inserts the string contained in the
4516 .Ql Ic ~i Ns \0Sign ) .
4517 The escape sequences tabulator
4525 Inserts the string contained in the
4528 .Ql Ic ~i Ns \0sign ) .
4529 The escape sequences tabulator
4536 .It Ic ~b Ar name ...
4537 Add the given names to the list of blind carbon copy recipients.
4540 .It Ic ~c Ar name ...
4541 Add the given names to the list of carbon copy recipients.
4545 Read the file specified by the
4547 variable into the message.
4551 Invoke the text editor on the message collected so far.
4552 After the editing session is finished,
4553 the user may continue appending text to the message.
4556 .It Ic ~F Ar messages
4557 Read the named messages into the message being sent, including all
4558 message headers and MIME parts.
4559 If no messages are specified, read in the current message.
4562 .It Ic ~f Ar messages
4563 Read the named messages into the message being sent.
4564 If no messages are specified, read in the current message.
4568 lists are used to modify the message headers.
4569 For MIME multipart messages,
4570 only the first printable part is included.
4574 Edit the message header fields
4580 by typing each one in turn and allowing the user to edit the field.
4581 The default values for these fields originate from the
4582 .Va from , replyto , sender
4589 Edit the message header fields
4595 by typing each one in turn and allowing the user to edit the field.
4598 .It Ic ~i Ar variable
4599 Insert the value of the specified variable into the message,
4600 adding a newline character at the end.
4601 The message remains unaltered if the variable is unset or empty.
4602 The escape sequences tabulator
4609 .It Ic ~M Ar messages
4610 Read the named messages into the message being sent,
4613 If no messages are specified, read the current message.
4616 .It Ic ~m Ar messages
4617 Read the named messages into the message being sent,
4620 If no messages are specified, read the current message.
4624 lists are used to modify the message headers.
4625 For MIME multipart messages,
4626 only the first printable part is included.
4630 Print out the message collected so far,
4631 prefaced by the message header fields
4632 and followed by the attachment list, if any.
4636 Abort the message being sent,
4637 copying it to the file specified by the
4644 .It Ic ~R Ar filename
4645 Read the named file into the message, indented by
4649 .It Ic ~r Ar filename
4650 Read the named file into the message.
4654 Cause the named string to become the current subject field.
4657 .It Ic ~t Ar name ...
4658 Add the given name(s) to the direct recipient list.
4661 .It Ic ~U Ar messages
4662 Read in the given / current message(s) excluding all headers, indented by
4666 .It Ic ~u Ar messages
4667 Read in the given / current message(s), excluding all headers.
4671 Invoke an alternate editor (defined by the
4673 option) on the message collected so far.
4674 Usually, the alternate editor will be a screen editor.
4675 After the editor is quit,
4676 the user may resume appending text to the end of the message.
4679 .It Ic ~w Ar filename
4680 Write the message onto the named file.
4682 the message is appended to it.
4688 except that the message is not saved at all.
4691 .It Ic ~| Ar command
4692 Pipe the message through the specified filter command.
4693 If the command gives no output or terminates abnormally,
4694 retain the original text of the message.
4697 is often used as a rejustifying filter.
4702 .\" .Sh INTERNAL VARIABLES {{{
4703 .Sh "INTERNAL VARIABLES"
4705 Internal \*(UA variables are controlled via the
4709 commands; prefixing a variable name with the string
4713 has the same effect as using
4719 Creation or editing of variables can be performed in the
4724 will give more insight on the given variable(s), and
4726 when called without arguments, will print a listing of all variables.
4727 Variables are also implicitly inherited from the program
4729 and can be set explicitly via the command line option
4733 Two different kind of variables exist.
4734 There are boolean variables, which can only be in one of the two states
4738 and value variables with a(n optional) string value.
4739 For the latter proper quoting is necessary upon assignment time:
4740 To embed whitespace (space and tabulator) in a value it either needs to
4741 be escaped with a backslash character, or the entire value must be
4742 enclosed in (double or single) quotation marks;
4743 To use quotation marks identical to those used to enclose the value,
4744 escape them with a backslash character.
4745 The backslash character has no special meaning except in these cases.
4747 .Bd -literal -offset indent
4748 set one=val\e 1 two="val 2" \e
4749 three='val "3"' four='val \e'4\e''
4750 varshow one two three four
4751 unset one two three four
4755 Dependent upon the actual option the string values will be interpreted
4756 as numbers, colour names, normal text etc., but there also exists
4757 a special kind of string value, the
4758 .Dq boolean string ,
4759 which must either be a decimal integer (in which case
4763 and any other value is true) or any of the (case-insensitive) strings
4768 for a false boolean and
4773 for a true boolean; a special kind of boolean string is the
4775 which is a boolean string that can optionally be prefixed with the
4776 (case-insensitive) term
4780 which causes prompting of the user in interactive mode, with the given
4781 boolean as the default value.
4783 .\" .Ss "Initial settings" {{{
4784 .\" (Keep in sync: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
4785 .Ss "Initial Settings"
4787 The standard POSIX 2008/Cor 1-2013 mandates the following initial
4793 .Pf no Va autoprint ,
4807 .Pf no Va ignoreeof ,
4809 .Pf no Va keepsave ,
4811 .Pf no Va outfolder ,
4816 (note that \*(UA deviates from the standard by using
4820 special prompt escape results in
4822 being printed unless
4828 .Pf no Va sendwait ,
4837 Notes: \*(UA doesn't support the
4839 variable \(en use command line options or
4840 .Va sendmail-arguments
4841 to pass options through to a MTA.
4842 And the default global
4844 file (which is loaded unless the
4846 command line flag has been used or the
4847 .Ev NAIL_NO_SYSTEM_RC
4848 environment variable is set) bends those initial settings a bit, e.g.,
4849 it sets the variables
4854 to name a few, calls
4856 etc., and should thus be taken into account.
4859 .\" .Ss "Variables" {{{
4862 .Bl -tag -width ".It Va _utoprin_"
4864 .It Va add-file-recipients
4865 \*(BO When file or pipe recipients have been specified,
4866 mention them in the corresponding address fields of the message instead
4867 of silently stripping them from their recipient list.
4868 By default such addressees are not mentioned.
4870 .Mx Va agent-shell-lookup
4871 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
4873 \*(IN\*(OP Account passwords can be fetched via an external agent
4874 program in order to permit encrypted password storage \(en see
4875 .Sx "On URL syntax and credential lookup"
4876 for more on credential lookup.
4877 If this is set then the content is interpreted as a shell command the
4878 output of which (with newline characters removed) is treated as the
4879 account password shall the command succeed (and have produced non-empty
4880 non-newline output); e.g., via
4882 .Bd -literal -offset indent
4883 $ echo PASSWORD > .pass
4885 $ eval `gpg-agent --daemon \e
4886 --pinentry-program=/usr/bin/pinentry-curses \e
4887 --max-cache-ttl 99999 --default-cache-ttl 99999`
4888 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
4892 A couple of environment variables will be set for the agent:
4894 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
4896 The temporary directory that \*(UA uses.
4897 Usually identical to
4899 but guaranteed to be set and usable by child processes;
4900 to ensure the latter condition for
4906 for which the password is looked up.
4907 .It Ev NAIL_USER_ENC
4908 The URL percent-encoded variant of
4911 The plain machine hostname of the user account.
4912 .It Ev NAIL_HOST_PORT
4915 (hostname possibly including port) of the user account.
4920 \*(BO Causes only the local part to be evaluated
4921 when comparing addresses.
4925 \*(BO Causes messages saved in
4927 to be appended to the end rather than prepended.
4928 This should always be set.
4932 \*(BO Causes \*(UA to prompt for the subject of each message sent.
4933 If the user responds with simply a newline,
4934 no subject field will be sent.
4938 \*(BO Causes the prompts for
4942 lists to appear after the message has been edited.
4946 \*(BO If set, \*(UA asks for files to attach at the end of each message,
4947 shall the list be found empty at that time.
4948 An empty line finalizes the list.
4952 \*(BO Causes the user to be prompted for carbon copy recipients
4953 (at the end of each message if
4957 are set) shall the list be found empty (at that time).
4958 An empty line finalizes the list.
4962 \*(BO Causes the user to be prompted for blind carbon copy
4963 recipients (at the end of each message if
4967 are set) shall the list be found empty (at that time).
4968 An empty line finalizes the list.
4972 \*(BO\*(OP Causes the user to be prompted if the message is to be
4973 signed at the end of each message.
4976 variable is ignored when this variable is set.
4980 \*(BO Alternative name for
4987 .It Va attachment-ask-content-description , \
4988 attachment-ask-content-disposition , \
4989 attachment-ask-content-id , \
4990 attachment-ask-content-type
4991 \*(BO If set then the user will be prompted for some attachment
4992 information when editing the attachment list.
4993 It is advisable to not use these but for the first of the variables;
4994 even for that it has to be noted that the data is used
5000 A sequence of characters to print in the
5004 as shown in the display of
5006 each for one type of messages (see
5007 .Sx "Message states" ) ,
5008 with the default being
5011 .Ql NU\ \ *HMFAT+\-$~
5014 variable is set, in the following order:
5016 .Bl -tag -compact -offset indent -width ".It Ql _"
5038 start of a collapsed thread.
5040 an uncollapsed thread (TODO ignored for now).
5044 classified as possible spam.
5050 Specifies a list of recipients to which a blind carbon copy of each
5051 outgoing message will be sent automatically.
5055 Specifies a list of recipients to which a carbon copy of each outgoing
5056 message will be sent automatically.
5060 \*(BO Causes threads to be collapsed automatically when threaded mode
5067 \*(BO Causes the delete command to behave like
5069 thus, after deleting a message the next one will be typed automatically.
5073 \*(BO\*(OB Causes threaded mode (see the
5075 command) to be entered automatically when a folder is opened.
5077 .Ql autosort=thread .
5081 Causes sorted mode (see the
5083 command) to be entered automatically with the value of this option as
5084 sorting method when a folder is opened, e.g.,
5085 .Ql set autosort=thread .
5089 \*(BO Enables the substitution of
5091 by the contents of the last command line in shell escapes.
5094 .It Va batch-exit-on-error
5095 \*(BO If the batch mode has been enabled via the
5097 command line option, then this variable will be consulted whenever \*(UA
5098 completes one operation (returns to the command prompt); if it is set
5099 then \*(UA will terminate if the last operation generated an error.
5103 \*(BO Causes automatic display of a header summary after executing a
5109 \*(BO Sets some cosmetical features to traditional BSD style;
5110 has the same affect as setting
5112 and all other variables prefixed with
5114 it also changes the meaning of the \*(UA specific
5117 escape sequence and changes behaviour of
5119 (which doesn't exist in BSD).
5123 \*(BO Changes the letters shown in the first column of a header
5124 summary to traditional BSD style.
5128 \*(BO Changes the display of columns in a header summary to traditional
5133 \*(BO Changes some informational messages to traditional BSD style.
5139 field to appear immediately after the
5141 field in message headers and with the
5143 .Sx "TILDE ESCAPES" .
5147 \*(BO Changes the output format of the
5149 command to traditional BSD style.
5153 The value that should appear in the
5157 MIME header fields when no character set conversion of the message data
5159 This defaults to US-ASCII, and the chosen character set should be
5160 US-ASCII compatible.
5164 \*(OP The default 8-bit character set that is used as an implicit last
5165 member of the variable
5167 This defaults to UTF-8.
5168 If no character set conversion capabilities are available in \*(UA then
5169 the only supported character set is
5171 Refer to the section
5172 .Sx "Character sets"
5173 for the complete picture of character set conversion in \*(UA.
5176 .It Va charset-unknown-8bit
5177 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5179 the content of a mail message by using a character set with the name
5181 Because of the unclassified nature of this character set \*(UA will not
5182 be capable to convert this character set to any other character set.
5183 If this variable is set any message part which uses the character set
5185 is assumed to really be in the character set given in the value,
5186 otherwise the (final) value of
5188 is used for this purpose.
5192 The default value for the
5197 .It Va colour-disable
5198 \*(BO\*(OP Forcefully disable usage of colours.
5199 Also see the section
5200 .Sx "Coloured message display" .
5204 \*(OP The colour specification for so-called
5208 .Sx "Coloured message display"
5209 for the format of the value.
5212 .It Va colour-header
5213 \*(OP The colour specification for header lines.
5216 .It Va colour-msginfo
5217 \*(OP The colour specification for the introductional message info line.
5221 \*(BO\*(OP Wether colour shall be used for output that is paged through
5223 Note that pagers may need special flags, e.g.,
5231 in order to support colours; therefore \*(UA will inspect the variable
5233 \(en if that starts with the string
5235 a non-existing environment variable
5242 will optionally be set to
5244 Also see the section
5245 .Sx "Coloured message display"
5249 .It Va colour-partinfo
5250 \*(OP The colour specification for MIME part info lines.
5254 \*(OP A comma-separated list of
5256 inals for which coloured message display can be used.
5257 Entries only need to be added if the string
5259 isn't part of the terminal name itself; the default value is
5261 .Dl cons25,linux,rxvt,rxvt-unicode,\:screen,\:sun,\:vt100,\:vt220,\:\
5265 .It Va colour-uheader
5266 \*(OP The colour specification for those header lines that have been
5268 .Va colour-user-headers
5271 .Sx "Coloured message display" .
5274 .It Va colour-user-headers
5275 A comma separated list of (case-insensitive) header names which should
5276 be colourized with the alternative
5279 The default value is
5284 In a(n interactive) terminal session, then if this valued option is set
5285 it'll be used as a threshold to determine how many lines the given
5286 output has to span before it will be displayed via the configured
5290 can be forced by setting this to the value
5292 setting it without a value will deduce the current height of the
5293 terminal screen to compute the treshold (see
5303 the message date, if any is to be displayed according to the format of
5305 is by default taken from the
5307 line of the message.
5308 If this variable is set the date as given in the
5310 header field is used instead, converted to local time.
5311 To control the display format of the date assign a valid
5316 format should not be used, because \*(UA doesn't take embedded newlines
5317 into account when calculating how many lines fit onto the screen.)
5319 .Va datefield-markout-older .
5322 .It Va datefield-markout-older
5323 This option, when set in addition to
5327 messages (concept is rather comparable to the
5329 option of the POSIX utility
5331 The content interpretation is identical to
5336 \*(BO Enables debug messages and obsoletion warnings, disables the
5337 actual delivery of messages and also implies
5344 \*(BY\*(OP\*(OB When an IMAP mailbox is selected and this variable is set,
5345 no connection to the server is initiated.
5346 Instead, data is obtained from the local cache (see
5349 Mailboxes that are not present in the cache
5350 and messages that have not yet entirely been fetched from the server
5352 to fetch all messages in a mailbox at once,
5354 .No ` Ns Li copy * /dev/null Ns '
5355 can be used while still in connected mode.
5356 Changes that are made to IMAP mailboxes in disconnected mode are queued
5357 and committed later when a connection to that server is made.
5358 This procedure is not completely reliable since it cannot be guaranteed
5359 that the IMAP unique identifiers (UIDs) on the server still match the
5360 ones in the cache at that time.
5363 when this problem occurs.
5365 .It Va disconnected-USER@HOST
5366 The specified account is handled as described for the
5369 but other accounts are not affected.
5372 .It Va disposition-notification-send
5374 .Ql Disposition-Notification-To:
5375 header (RFC 3798) with the message.
5379 .\" TODO .It Va disposition-notification-send-HOST
5381 .\".Va disposition-notification-send
5382 .\" for SMTP accounts on a specific host.
5383 .\" TODO .It Va disposition-notification-send-USER@HOST
5385 .\".Va disposition-notification-send
5386 .\"for a specific account.
5390 \*(BO When dot is set, a period
5392 on a line by itself during message input in (interactive) compose mode
5393 will be treated as end-of-message (in addition to the normal end-of-file
5402 .It Va dotlock-ignore-error
5403 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5404 mailboxes (see the command
5406 will be protected with so-called dotlock files\(emthe traditional mail
5407 spool file locking method\(emin addition to system file locking.
5408 Because \*(UA ships with a privilege-separated dotlock creation program
5409 that should always be able to create such a dotlock file there is no
5410 good reason to ignore dotlock file creation errors, and thus these are
5411 fatal unless this variable is set.
5415 \*(BO If this variable is set then the editor is started automatically
5416 when a message is composed in interactive mode, as if the
5422 variable is implied for this automatically spawned editor session.
5426 \*(BO When a message is edited while being composed,
5427 its header is included in the editable text.
5438 fields are accepted within the header, other fields are ignored.
5442 \*(BO When entering interactive mode \*(UA normally writes
5443 .Dq \&No mail for user
5444 and exits immediately if a mailbox is empty or doesn't exist.
5445 If this option is set \*(UA starts even with an empty or nonexistent
5446 mailbox (the latter behaviour furtherly depends upon
5452 Suggestion for the MIME encoding to use in outgoing text messages
5454 Valid values are the default
5455 .Ql quoted-printable ,
5460 may cause problems when transferring mail messages over channels that
5461 are not ESMTP (RFC 1869) compliant.
5462 If there is no need to encode a message,
5464 transfer mode is always used regardless of this variable.
5465 Binary data is always encoded as
5470 If defined, the first character of this option
5471 gives the character to use in place of
5474 .Sx "TILDE ESCAPES" .
5478 If not set then file and command pipeline targets are not allowed,
5479 and any such address will be filtered out, giving a warning message.
5480 If set without a value then all possible recipient address
5481 specifications will be accepted \(en see the section
5482 .Sx "On sending mail, and non-interactive mode"
5484 To accept them, but only in interactive mode, or when tilde commands
5485 were enabled explicitly by using one of the command line options
5489 set this to the (case-insensitive) value
5491 (note right now this is actually like setting
5492 .Ql restrict,-all,+name,+addr ) .
5494 In fact the value is interpreted as a comma-separated list of values.
5497 then the existence of disallowed specifications is treated as a hard
5498 send error instead of only filtering them out.
5499 The remaining values specify wether a specific type of recipient
5500 address specification is allowed (optionally indicated by a plus sign
5502 prefix) or disallowed (prefixed with a hyphen
5506 addresses all possible address specifications,
5510 command pipeline targets,
5512 plain user names and (MTA) aliases (\*(OB
5514 may be used as an alternative syntax to
5519 These kind of values are interpreted in the given order, so that
5520 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5521 will cause hard errors for any non-network address recipient address
5522 unless \*(UA is in interactive mode or has been started with the
5526 command line option; in the latter case(s) any address may be used, then.
5530 Unless this variable is set additional mail-transfer-agent (MTA)
5531 arguments from the command line, as can be given after a
5533 separator, are ignored due to safety reasons.
5534 However, if set to the special value
5536 then the presence of additional MTA arguments is treated as a hard
5537 error that causes \*(UA to exit with failure status.
5538 A lesser strict variant is the otherwise identical
5540 which does accept such arguments in interactive mode, or if tilde
5541 commands were enabled explicitly by using one of the command line options
5548 \*(RO Information on the features compiled into \*(UA \(en the content
5549 of this variable is identical to the output of the command
5554 \*(BO This option reverses the meanings of a set of reply commands,
5555 turning the lowercase variants, which by default address all recipients
5556 included in the header of a message
5557 .Pf ( Ic reply , respond , followup )
5558 into the uppercase variants, which by default address the sender only
5559 .Pf ( Ic Reply , Respond , Followup )
5562 .Ic replysender , respondsender , followupsender
5564 .Ic replyall , respondall , followupall
5565 are not affected by the current setting of
5570 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5571 It is possible to install file hooks which will be used by the
5573 command in order to be able to transparently handle (through an
5574 intermediate temporary file) files with specific
5576 s: the variable values can include shell snippets and are expected to
5577 write data to standard output / read data from standard input,
5579 \*(ID The variables may not be changed while there is a mailbox
5581 .Bd -literal -offset indent
5582 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5583 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5584 record=+null-sent.xy
5589 The name of the directory to use for storing folders of messages.
5590 All folder names that begin with
5592 refer to files below it.
5593 The same special conventions as documented for the
5595 command may be used when specifying a new value for
5597 but be aware that the expansion is fully performed immediately.
5598 E.g., if the expanded name refers to an IMAP account, all names that
5599 begin with `+' refer to IMAP mailboxes below the
5603 Note: some IMAP servers do not accept the creation of mailboxes in
5604 the hierarchy base, but require that they are created as subfolders of
5605 `INBOX' \(en with such servers a folder name of the form
5607 .Dl imaps://mylogin@imap.myisp.example/INBOX.
5609 should be used (the last character is the server's hierarchy delimiter).
5610 Folder names prefixed by `+' will then refer to folders below `INBOX',
5611 while folder names prefixed by `@' refer to folders below the hierarchy
5615 namespace command for a method to detect the appropriate prefix and
5620 This variable can be set to the name of a
5622 macro which will be called whenever a
5625 The macro will also be invoked when new mail arrives,
5626 but message lists for commands executed from the macro
5627 only include newly arrived messages then.
5630 are activated in a folder hook, then the covered settings will be
5631 reverted once the folder is left again.
5632 .Bd -filled -offset indent
5634 Macro behaviour, including option localization, will change in v15.
5635 To be on the absolutely safe side and avoid any surprises it may be wise
5636 to use wrappers that depend on the program version, e.g.,:
5638 .Bd -literal -offset indent
5639 if $version-major < 15
5645 echo "Please re-verify sent-hook (post v15)"
5648 folder-hook-+sent=sent-hook
5652 .It Va folder-hook-FOLDER
5657 Unlike other folder specifications, the fully expanded name of a folder,
5658 without metacharacters, is used to avoid ambiguities.
5659 However, if the mailbox resides under
5663 specification is tried in addition, e.g., if
5667 (and thus relative to the user's home directory) then
5668 .Pa /home/usr1/mail/sent
5670 .Ql folder-hook-/home/usr1/mail/sent
5671 first, but then followed by
5672 .Ql folder-hook-+sent .
5676 \*(BO Controls wether a
5677 .Ql Mail-Followup-To:
5678 header is generated when sending messages to known mailing lists.
5680 .Va followup-to-honour
5682 .Ic mlist , mlsubscribe , reply
5687 .It Va followup-to-honour
5689 .Ql Mail-Followup-To:
5690 header is honoured when group-replying to a message via
5694 This is a quadoption; if set without a value it defaults to
5704 .It Va forward-as-attachment
5705 \*(BO Original messages are normally sent as inline text with the
5708 and only the first part of a multipart message is included.
5709 With this option messages are sent as unmodified MIME
5711 attachments with all of their parts included.
5715 The address (or a list of addresses) to put into the
5717 field of the message header, quoting RFC 5322:
5718 the author(s) of the message, that is, the mailbox(es) of the person(s)
5719 or system(s) responsible for the writing of the message.
5720 If replying to messages these addresses are handled as if they were in
5724 If the machine's hostname is not valid at the Internet (for example at
5725 a dialup machine) then either this variable or
5730 adds even more fine-tuning capabilities),
5734 contains more than one address,
5737 variable is required (according to the standard RFC 5322).
5741 \*(BO When replying to or forwarding a message \*(UA normally removes
5742 the comment and name parts of email addresses.
5743 If this variable is set such stripping is not performed,
5744 and comments, names etc. are retained.
5748 The string to print before the text of a message with the
5752 .Va forward-as-attachment
5755 .Dq -------- Original Message --------
5756 if unset; No heading is printed if it is set to the empty string.
5760 \*(BO Causes the header summary to be written at startup and after
5761 commands that affect the number of messages or the order of messages in
5762 the current folder; enabled by default.
5763 The command line option
5771 A format string to use for the summary of
5773 similar to the ones used for
5776 Format specifiers in the given string start with a percent character
5778 and may be followed by an optional decimal number indicating the field
5779 width \(em if that is negative, the field is to be left-aligned.
5780 Valid format specifiers are:
5783 .Bl -tag -compact -offset indent -width "_%%_"
5785 A plain percent character.
5788 a space character but for the current message
5790 for which it expands to
5794 a space character but for the current message
5796 for which it expands to
5799 \*(OP The spam score of the message, as has been classified via the
5802 Prints only a replacement character if there is no spam support.
5804 Message attribute character (status flag); the actual content can be
5808 The date when the message was received, or the date found in the
5812 variable is set (optionally to a date display format string).
5814 The indenting level in threaded mode.
5816 The address of the message sender.
5818 The message thread tree structure.
5819 (Note that this format doesn't support a field width.)
5821 The number of lines of the message, if available.
5825 The number of octets (bytes) in the message, if available.
5827 Message subject (if any).
5829 Message subject (if any) in double quotes.
5831 Message recipient flags: is the addressee of the message a known or
5832 subscribed mailing list \(en see
5837 The position in threaded/sorted order.
5841 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
5843 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
5854 .It Va headline-bidi
5855 Bidirectional text requires special treatment when displaying headers,
5856 because numbers (in dates or for file sizes etc.) will not affect the
5857 current text direction, in effect resulting in ugly line layouts when
5858 arabic or other right-to-left text is to be displayed.
5859 On the other hand only a minority of terminals is capable to correctly
5860 handle direction changes, so that user interaction is necessary for
5862 Note that extended host system support is required nonetheless, e.g.,
5863 detection of the terminal character set is one precondition;
5864 and this feature only works in an Unicode (i.e., UTF-8) locale.
5866 In general setting this variable will cause \*(UA to encapsulate text
5867 fields that may occur when printing
5869 (and some other fields, like dynamic expansions in
5871 with special Unicode control sequences;
5872 it is possible to fine-tune the terminal support level by assigning
5874 no value (or any value other than
5879 will make \*(UA assume that the terminal is capable to properly deal
5880 with Unicode version 6.3, in which case text is embedded in a pair of
5881 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
5883 In addition no space on the line is reserved for these characters.
5885 Weaker support is chosen by using the value
5887 (Unicode 6.3, but reserve the room of two spaces for writing the control
5888 sequences onto the line).
5893 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
5894 again reserves room for two spaces in addition.
5898 \*(OP If a command line editor is available then this can be set to
5899 name the (expandable) path of the location of a permanent history file.
5902 .It Va history-gabby
5903 \*(BO\*(OP Add more entries to the history as is normally done.
5906 .It Va history-gabby-persist
5907 \*(BO\*(OP \*(UA's own MLE will not save the additional
5909 entries in persistent storage unless this variable is set.
5910 On the other hand it will not loose the knowledge of wether a persistent
5911 entry was gabby or not.
5917 \*(OP If a command line editor is available this value restricts the
5918 amount of history entries that are saved into a set and valid
5920 A value of less than 0 disables this feature;
5921 note that loading and incorporation of
5923 upon program startup can also be suppressed by doing this.
5924 An unset or invalid value, or 0, causes a default value to be used.
5925 Dependent on the available command line editor this will also define the
5926 number of history entries in memory;
5927 it is also editor-specific wether runtime updates of this value will be
5932 \*(BO This option is used to hold messages in the system mailbox,
5933 and it is set by default.
5937 Use this string as hostname when expanding local addresses instead of
5938 the value obtained from
5949 transport is not used then it is normally the responsibility of the MTA
5950 to create these fields, \*(IN in conjunction with
5954 also influences the results;
5955 you should produce some test messages with the desired combination of
5964 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
5965 names according to the rules of IDNA (internationalized domain names
5967 Since the IDNA code assumes that domain names are specified with the
5969 character set, an UTF-8 locale charset is required to represent all
5970 possible international domain names (before conversion, that is).
5974 \*(BO Ignore interrupt signals from the terminal while entering
5975 messages; instead echo them as
5977 characters and discard the current line.
5981 \*(BO Ignore end-of-file conditions
5982 .Pf ( Ql control-D )
5983 in compose mode on message input and in interactive command input.
5984 If set an interactive command input session can only be left by
5985 explicitly using one of the commands
5989 and message input in compose mode can only be terminated by entering
5992 on a line by itself or by using the
5994 .Sx "TILDE ESCAPES" ;
5996 overrides a setting of
6000 .It Va imap-auth-USER@HOST , imap-auth
6001 \*(OP\*(OB Sets the IMAP authentication method.
6002 Valid values are `login' for the usual password-based authentication
6004 `cram-md5', which is a password-based authentication that does not send
6005 the password over the network in clear text,
6006 and `gssapi' for GSS-API based authentication.
6010 \*(OP\*(OB Enables caching of IMAP mailboxes.
6011 The value of this variable must point to a directory that is either
6012 existent or can be created by \*(UA.
6013 All contents of the cache can be deleted by \*(UA at any time;
6014 it is not safe to make assumptions about them.
6016 .Mx Va imap-keepalive
6017 .It Va imap-keepalive-USER@HOST , imap-keepalive-HOST , imap-keepalive
6018 \*(OP\*(OB IMAP servers may close the connection after a period of
6019 inactivity; the standard requires this to be at least 30 minutes,
6020 but practical experience may vary.
6021 Setting this variable to a numeric `value' greater than 0 causes
6022 a `NOOP' command to be sent each `value' seconds if no other operation
6026 .It Va imap-list-depth
6027 \*(OP\*(OB When retrieving the list of folders on an IMAP server, the
6029 command stops after it has reached a certain depth to avoid possible
6031 The value of this variable sets the maximum depth allowed.
6033 If the folder separator on the current IMAP server is a slash `/',
6034 this variable has no effect and the
6036 command does not descend to subfolders.
6038 .Mx Va imap-use-starttls
6039 .It Va imap-use-starttls-USER@HOST , imap-use-starttls-HOST , imap-use-starttls
6040 \*(OP\*(OB Causes \*(UA to issue a `STARTTLS' command to make an unencrypted
6041 IMAP session SSL/TLS encrypted.
6042 This functionality is not supported by all servers,
6043 and is not used if the session is already encrypted by the IMAPS method.
6054 option for indenting messages,
6055 in place of the normal tabulator character
6057 which is the default.
6058 Be sure to quote the value if it contains spaces or tabs.
6062 \*(BO If set, an empty mailbox file is not removed.
6063 This may improve the interoperability with other mail user agents
6064 when using a common folder directory, and prevents malicious users
6065 from creating fake mailboxes in a world-writable spool directory.
6066 Note this only applies to local regular (MBOX) files, other mailbox
6067 types will never be removed.
6070 .It Va keep-content-length
6071 \*(BO When (editing messages and) writing
6073 mailbox files \*(UA can be told to keep the
6077 header fields that some MUAs generate by setting this variable.
6078 Since \*(UA does neither use nor update these non-standardized header
6079 fields (which in itself shows one of their conceptual problems),
6080 stripping them should increase interoperability in between MUAs that
6081 work with with same mailbox files.
6082 Note that, if this is not set but
6083 .Va writebackedited ,
6084 as below, is, a possibly performed automatic stripping of these header
6085 fields already marks the message as being modified.
6089 \*(BO When a message is saved it is usually discarded from the
6090 originating folder when \*(UA is quit.
6091 Setting this option causes all saved message to be retained.
6094 .It Va line-editor-cursor-right
6095 \*(OP If the builtin command line editor is used, actions which are
6096 based on rightwise movement may not work on some terminals.
6097 If you encounter such problems, set this variable to the terminal
6098 control sequence that is necessary to move the cursor one column to the
6102 which should work for most terminals.
6109 and other control character have to be written as shell-style escape
6116 .It Va line-editor-disable
6117 \*(BO Turn off any enhanced line editing capabilities (see
6118 .Sx "Command line editor"
6123 \*(BO When a message is replied to and this variable is set,
6124 it is marked as having been answered.
6125 This mark has no technical meaning in the mail system;
6126 it just causes messages to be marked in the header summary,
6127 and makes them specially addressable.
6131 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6133 Messages which are fetched over the network or from within already
6134 existing Maildir (or any non-MBOX) mailboxes may require so-called
6136 quoting (insertion of additional
6138 characters to prevent line content misinterpretation) to be applied in
6139 order to be storable in MBOX mailboxes, however, dependent on the
6140 circumspection of the message producer.
6141 (E.g., \*(UA itself will, when newly generating messages, choose a
6142 .Pf Content-Transfer- Va encoding
6143 that prevents the necessity for such quoting \(en a necessary
6144 precondition to ensure message checksums won't change.)
6146 By default \*(UA will perform this
6148 quoting in a way that results in a MBOX file that is compatible with
6149 the POSIX MBOX layout, which means that, in order not to exceed the
6150 capabilities of simple applications, many more
6152 lines get quoted (thus modified) than necessary according to RFC 4155.
6153 Set this option to instead generate MBOX files which comply to RFC 4155.
6157 \*(BO Internal development variable.
6160 .It Va message-id-disable
6161 \*(BO By setting this option the generation of
6163 can be completely suppressed, effectively leaving this task up to the
6164 mail-transfer-agent (MTA) or the SMTP server.
6165 (According to RFC 5321 your SMTP server is not required to add this
6166 field by itself, so you should ensure that it accepts messages without a
6170 .It Va message-inject-head
6171 A string to put at the beginning of each new message.
6172 The escape sequences tabulator
6179 .It Va message-inject-tail
6180 A string to put at the end of each new message.
6181 The escape sequences tabulator
6189 \*(BO Usually, when an
6191 expansion contains the sender, the sender is removed from the expansion.
6192 Setting this option suppresses these removals.
6197 option to be passed to mail-transfer-agents (MTAs);
6198 though most of the modern MTAs don't (no longer) document this flag, no
6199 MTA is known which doesn't support it (for historical compatibility).
6202 .It Va mime-allow-text-controls
6203 \*(BO When sending messages, each part of the message is MIME-inspected
6204 in order to classify the
6207 .Ql Content-Transfer-Encoding:
6210 that is required to send this part over mail transport, i.e.,
6211 a computation rather similar to what the
6213 command produces when used with the
6217 This classification however treats text files which are encoded in
6218 UTF-16 (seen for HTML files) and similar character sets as binary
6219 octet-streams, forcefully changing any
6224 .Ql application/octet-stream :
6225 If that actually happens a yet unset charset MIME parameter is set to
6227 effectively making it impossible for the receiving MUA to automatically
6228 interpret the contents of the part.
6230 If this option is set, and the data was unambiguously identified as text
6231 data at first glance (by a
6235 file extension), then the original
6237 will not be overwritten.
6240 .It Va mime-alternative-favour-rich
6241 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6242 HTML) will be preferred in favour of included plain text versions when
6243 displaying messages, provided that a handler exists which produces
6244 output that can be (re)integrated into \*(UA's normal visual display.
6245 (E.g., at the time of this writing some newsletters ship their full
6246 content only in the rich HTML part, whereas the plain text part only
6247 contains topic subjects.)
6250 .It Va mime-counter-evidence
6253 field is used to decide how to handle MIME parts.
6254 Some MUAs however don't use
6256 or a similar mechanism to correctly classify content, but simply specify
6257 .Ql application/octet-stream ,
6258 even for plain text attachments like
6260 If this variable is set then \*(UA will try to classify such MIME
6261 message parts on its own, if possible, for example via a possibly
6262 existent attachment filename.
6263 A non-empty value may also be given, in which case a number is expected,
6264 actually a carrier of bits.
6265 Creating the bit-carrying number is a simple addition:
6266 .Bd -literal -offset indent
6267 ? !echo Value should be set to $((2 + 4 + 8))
6268 Value should be set to 14
6271 .Bl -bullet -compact
6273 If bit two is set (2) then the detected
6275 content-type will be carried along with the message and be used for
6277 .Va pipe-TYPE/SUBTYPE
6278 is responsible for the MIME part, shall that question arise;
6279 when displaying such a MIME part the part-info will indicate the
6280 overridden content-type by showing a plus-sign
6283 If bit three is set (4) then the counter-evidence is always produced
6284 and a positive result will be used as the MIME type, even forcefully
6285 overriding the parts given MIME type.
6287 If bit four is set (8) then as a last resort the actual content of
6288 .Ql application/octet-stream
6289 parts will be inspected, so that data which looks like plain text can be
6294 .It Va mimetypes-load-control
6295 This option can be used to control which of the
6297 databases are loaded by \*(UA, as furtherly described in the section
6298 .Sx "The mime.types files" .
6301 is part of the option value, then the user's personal
6303 file will be loaded (if it exists); likewise the letter
6305 controls loading of the system wide
6306 .Pa /etc/mime.types ;
6307 directives found in the user file take precedence, letter matching is
6309 If this option is not set \*(UA will try to load both files.
6310 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6311 but they will be matched last.
6313 More sources can be specified by using a different syntax: if the
6314 value string contains an equals sign
6316 then it is instead parsed as a comma-separated list of the described
6319 pairs; the given filenames will be expanded and loaded, and their
6320 content may use the extended syntax that is described in the section
6321 .Sx "The mime.types files" .
6322 Directives found in such files always take precedence (are prepended to
6323 the MIME type cache).
6326 .It Va NAIL_EXTRA_RC
6327 The name of an optional startup file to be read after
6329 This variable has an effect only if it is set in
6333 it is not imported from the environment in order to honour
6334 .Ql MAILRC=/dev/null Ns /
6337 Use this file for commands that are not understood by other POSIX
6342 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6343 \*(BO\*(IN\*(OP Used to control usage of the users
6345 file for lookup of account credentials, as documented in the section
6346 .Sx "On URL syntax and credential lookup"
6350 .Sx "The .netrc file"
6351 documents the file format.
6355 If this variable has the value
6357 newly created local folders will be in Maildir format.
6361 Checks for new mail in the current folder each time the prompt is
6363 For IMAP mailboxes the server is then polled for new mail,
6364 which may result in delayed operation if the connection to the server is
6366 A Maildir folder must be re-scanned to determine if new mail has arrived.
6368 If this variable is set to the special value
6370 an IMAP server is not actively asked for new mail, but new mail may
6371 still be detected and announced with any other IMAP command that is sent
6373 In either case the IMAP server may send notifications about messages
6374 that have been deleted on the server by another process or client.
6376 .Dq Expunged X messages
6377 is printed regardless of this variable, and message numbers may have
6380 If this variable is set to the special value
6382 then a Maildir folder will not be rescanned completely, but only
6383 timestamp changes are detected.
6387 \*(BO Causes the filename given in the
6390 and the sender-based filenames for the
6394 commands to be interpreted relative to the directory given in the
6396 variable rather than to the current directory,
6397 unless it is set to an absolute pathname.
6401 \*(BO If set, each message feed through the command given for
6403 command prints out is followed by a formfeed character
6407 .It Va password-USER@HOST , password-HOST , password
6408 \*(IN Variable chain that sets a password, which is used in case none has
6409 been given in the protocol and account-specific URL;
6410 as a last resort \*(UA will ask for a password on the user's terminal if
6411 the authentication method requires a password.
6412 Specifying passwords in a startup file is generally a security risk;
6413 the file should be readable by the invoking user only.
6415 .It Va password-USER@HOST
6416 \*(OU (see the chain above for \*(IN)
6417 Set the password for
6421 If no such variable is defined for a host,
6422 the user will be asked for a password on standard input.
6423 Specifying passwords in a startup file is generally a security risk;
6424 the file should be readable by the invoking user only.
6428 \*(BO Send messages to the
6430 command without performing MIME and character set conversions.
6434 .It Va pipe-TYPE/SUBTYPE
6435 When a MIME message part of type
6437 (case-insensitive) is displayed or quoted,
6438 its text is filtered through the value of this variable interpreted as
6442 forces interpretation of the message part as plain text, e.g.,
6443 .Ql set pipe-application/xml=@
6444 will henceforth display XML
6446 (The same could also be achieved by adding a MIME type marker with the
6449 And \*(OPally MIME type handlers may be defined via
6450 .Sx "The Mailcap files"
6451 \(em corresponding flag strings are shown in parenthesis below.)
6456 can in fact be used to adjust usage and behaviour of a following shell
6457 command specification by appending trigger characters to it, e.g., the
6458 following hypothetical command specification could be used:
6459 .Bd -literal -offset indent
6460 set pipe-X/Y="@*!++=@vim ${NAIL_FILENAME_TEMPORARY}"
6464 .Bl -tag -compact -width ".It Ql __"
6466 Simply by using the special
6468 prefix the MIME type (shell command) handler will only be invoked to
6469 display or convert the MIME part if the message is addressed directly
6470 and alone by itself.
6471 Use this trigger to disable this and always invoke the handler
6472 .Pf ( Cd x-mailx-always ) .
6475 If set the handler will not be invoked when a message is to be quoted,
6476 but only when it will be displayed
6477 .Pf ( Cd x-mailx-noquote ) .
6480 The command will be run asynchronously, i.e., without blocking \*(UA,
6481 which may be a handy way to display a, e.g., PDF file while also
6482 continuing to read the mail message
6483 .Pf ( Cd x-mailx-async ) .
6484 Asynchronous execution implies
6488 The command must be run on an interactive terminal, \*(UA will
6489 temporarily release the terminal to it
6490 .Pf ( Cd needsterminal ) .
6491 This flag is mutual exclusive with
6493 will only be used in interactive mode and implies
6497 Request creation of a zero-sized temporary file, the absolute pathname
6498 of which will be made accessable via the environment variable
6499 .Ev NAIL_FILENAME_TEMPORARY
6500 .Pf ( Cd x-mailx-tmpfile ) .
6501 If this trigger is given twice then the file will be unlinked
6502 automatically by \*(UA when the command loop is entered again at latest
6503 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6504 (Don't use this for asynchronous handlers.)
6507 Normally the MIME part content is passed to the handler via standard
6508 input; if this flag is set then the data will instead be written into
6509 .Ev NAIL_FILENAME_TEMPORARY
6510 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6511 the creation of which is implied; note however that in order to cause
6512 deletion of the temporary file you still have to use two plus signs
6517 To avoid ambiguities with normal shell command content you can use
6518 another at-sign to forcefully terminate interpretation of remaining
6520 (Any character not in this list will have the same effect.)
6524 Some information about the MIME part to be displayed is embedded into
6525 the environment of the shell command:
6528 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6531 The MIME content-type of the part, if known, the empty string otherwise.
6534 .It Ev NAIL_CONTENT_EVIDENCE
6536 .Va mime-counter-evidence
6537 includes the carry-around-bit (2), then this will be set to the detected
6538 MIME content-type; not only then identical to
6539 .Ev \&\&NAIL_CONTENT
6543 .It Ev NAIL_FILENAME
6544 The filename, if any is set, the empty string otherwise.
6547 .It Ev NAIL_FILENAME_GENERATED
6551 .It Ev NAIL_FILENAME_TEMPORARY
6552 If temporary file creation has been requested through the command prefix
6553 this variable will be set and contain the absolute pathname of the
6558 The temporary directory that \*(UA uses.
6559 Usually identical to
6561 but guaranteed to be set and usable by child processes;
6562 to ensure the latter condition for
6569 .It Va pipe-EXTENSION
6570 This is identical to
6571 .Va pipe-TYPE/SUBTYPE
6574 (normalized to lowercase using character mappings of the ASCII charset)
6575 names a file extension, e.g.,
6577 Handlers registered using this method take precedence.
6580 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6581 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6582 The only possible value as of now is
6584 which is thus the default.
6587 .Mx Va pop3-bulk-load
6588 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6589 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6590 the messages, and only requests the message bodies on user request.
6591 For the POP3 protocol this means that the message headers will be
6593 If this option is set then \*(UA will download only complete messages
6594 from the given POP3 server(s) instead.
6596 .Mx Va pop3-keepalive
6597 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6598 \*(OP POP3 servers close the connection after a period of inactivity;
6599 the standard requires this to be at least 10 minutes,
6600 but practical experience may vary.
6601 Setting this variable to a numeric value greater than
6605 command to be sent each value seconds if no other operation is performed.
6608 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6609 \*(BO\*(OP Unless this variable is set the
6611 authentication method will be used when connecting to a POP3 server that
6615 is that the password is not sent in clear text over the wire and that
6616 only a single packet is sent for the user/password tuple.
6618 .Va pop3-no-apop-HOST
6621 .Mx Va pop3-use-starttls
6622 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6623 \*(BO\*(OP Causes \*(UA to issue a
6625 command to make an unencrypted POP3 session SSL/TLS encrypted.
6626 This functionality is not supported by all servers,
6627 and is not used if the session is already encrypted by the POP3S method.
6629 .Va pop3-use-starttls-HOST
6633 .It Va print-all-chars
6634 \*(BY This option causes all characters to be considered printable.
6635 It is only effective if given in a startup file.
6636 With this option set some character sequences in messages may put the
6637 user's terminal in an undefined state when printed;
6638 it should only be used as a last resort if no working system locale can
6642 .It Va print-alternatives
6643 \*(BO When a MIME message part of type
6644 .Ql multipart/alternative
6645 is displayed and it contains a subpart of type
6647 other parts are normally discarded.
6648 Setting this variable causes all subparts to be displayed,
6649 just as if the surrounding part was of type
6650 .Ql multipart/mixed .
6654 The string printed when a command is accepted.
6655 Prompting may be prevented by either setting this to the null string
6658 The same XSI escape sequences that are understood by the
6660 command may be used within
6663 In addition, the following \*(UA specific additional sequences are
6670 is set, in which case it expands to
6674 is the default value of
6677 which will expand to
6679 if the last command failed and to
6683 which will expand to the name of the currently active
6685 if any, and to the empty string otherwise, and
6687 which will expand to the name of the currently active mailbox.
6688 (Note that the prompt buffer is size-limited, excess is cut off.)
6694 to encapsulate the expansions of the
6698 escape sequences as necessary to correctly display bidirectional text,
6699 this is not true for the final string that makes up
6701 as such, i.e., real BIDI handling is not supported.
6703 When a newer version of the
6705 .Sx "Command line editor"
6706 is used, any escape sequence must itself be encapsulated with another
6707 escape character for usage with the
6709 mechanism: \*(UA configures the control character
6715 \*(BO Suppresses the printing of the version when first invoked.
6719 If set, \*(UA starts a replying message with the original message
6720 prefixed by the value of the variable
6722 Normally, a heading consisting of
6723 .Dq Fromheaderfield wrote:
6724 is printed before the quotation.
6729 variable, this heading is omitted.
6732 is assigned, the headers selected by the
6733 .Ic ignore Ns / Ns Ic retain
6734 commands are printed above the message body,
6737 acts like an automatic
6743 is assigned, all headers are printed above the message body and all MIME
6744 parts are included, making
6746 act like an automatic
6749 .Va quote-as-attachment .
6752 .It Va quote-as-attachment
6753 \*(BO Add the original message in its entirety as a
6755 MIME attachment when replying to a message.
6756 Note this works regardless of the setting of
6761 \*(OP Can be set in addition to
6763 Setting this turns on a more fancy quotation algorithm in that leading
6764 quotation characters are compressed and overlong lines are folded.
6766 can be set to either one or two (space separated) numeric values,
6767 which are interpreted as the maximum (goal) and the minimum line length,
6768 respectively, in a spirit rather equal to the
6770 program, but line-, not paragraph-based.
6771 If not set explicitly the minimum will reflect the goal algorithmically.
6772 The goal can't be smaller than the length of
6774 plus some additional pad.
6775 Necessary adjustments take place silently.
6778 .It Va recipients-in-cc
6779 \*(BO On group replies, specify only the sender of the original mail in
6781 and mention the other recipients in the secondary
6783 By default all recipients of the original mail will be addressed via
6788 If defined, gives the pathname of the folder used to record all outgoing
6790 If not defined, then outgoing mail is not saved.
6791 When saving to this folder fails the message is not sent,
6792 but instead saved to
6796 .It Va record-resent
6797 \*(BO If both this variable and the
6804 commands save messages to the
6806 folder as it is normally only done for newly composed messages.
6809 .It Va reply-in-same-charset
6810 \*(BO If this variable is set \*(UA first tries to use the same
6811 character set of the original message for replies.
6812 If this fails, the mechanism described in
6813 .Sx "Character sets"
6814 is evaluated as usual.
6817 .It Va reply_strings
6818 Can be set to a comma-separated list of (case-insensitive according to
6819 ASCII rules) strings which shall be recognized in addition to the
6822 reply message indicators \(en builtin are
6824 which is mandated by RFC 5322, as well as the german
6829 A list of addresses to put into the
6831 field of the message header.
6832 Members of this list are handled as if they were in the
6837 .It Va reply-to-honour
6840 header is honoured when replying to a message via
6844 This is a quadoption; if set without a value it defaults to
6848 .It Va rfc822-body-from_
6849 \*(BO This variable can be used to force displaying a so-called
6851 line for messages that are embedded into an envelope mail via the
6853 MIME mechanism, for more visual convenience.
6857 \*(BO Enable saving of (partial) messages in
6859 upon interrupt or delivery error.
6863 When \*(UA initially prints the message headers it determines the number
6864 to print by looking at the speed of the terminal.
6865 The faster the terminal, the more it prints.
6866 This option overrides this calculation and specifies how many message
6867 headers are printed.
6868 This number is also used for scrolling with the
6871 Overall screen dimensions and pager usage is influenced by the
6872 environment variables
6880 .It Va searchheaders
6881 \*(BO Expand message-list specifiers in the form
6883 to all messages containing the substring
6887 The string search is case insensitive.
6891 \*(OP A comma-separated list of character set names that can be used in
6892 outgoing internet mail.
6893 The value of the variable
6895 is automatically appended to this list of character-sets.
6896 If no character set conversion capabilities are compiled into \*(UA then
6897 the only supported charset is
6900 .Va sendcharsets-else-ttycharset
6901 and refer to the section
6902 .Sx "Character sets"
6903 for the complete picture of character set conversion in \*(UA.
6906 .It Va sendcharsets-else-ttycharset
6907 \*(BO\*(OP If this variable is set, but
6909 is not, then \*(UA acts as if
6911 had been set to the value of the variable
6913 In effect this combination passes through the message data in the
6914 character set of the current locale (given that
6916 hasn't been set manually), i.e., without converting it to the
6918 fallback character set.
6919 Thus, mail message text will be in ISO-8859-1 encoding when send from
6920 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
6922 If no character set conversion capabilities are available in \*(UA then
6923 the only supported character set is
6928 An address that is put into the
6930 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6931 responsible for the actual transmission of the message.
6932 This field should normally not be used unless the
6934 field contains more than one address, on which case it is required.
6937 address is handled as if it were in the
6943 To use an alternate mail transport agent (MTA),
6944 set this option to the full pathname of the program to use.
6945 It may be necessary to set
6946 .Va sendmail-progname
6949 The MTA will be passed command line arguments from several possible
6950 sources: from the variable
6951 .Va sendmail-arguments
6952 if set, from the command line if given and the variable
6955 Argument processing of the MTA will be terminated with a
6959 The otherwise occurring implicit usage of the following MTA command line
6960 arguments can be disabled by setting the boolean option
6961 .Va sendmail-no-default-arguments
6962 (which will also disable passing
6966 (for not treating a line with only a dot
6968 character as the end of input),
6976 option is set); in conjunction with the
6978 command line option \*(UA will also pass
6984 .It Va sendmail-arguments
6985 Arguments to pass through to the Mail-Transfer-Agent can be given via
6987 The content of this variable will be split up in a vector of arguments
6988 which will be joined onto other possible MTA options:
6990 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
6993 .It Va sendmail-no-default-arguments
6994 \*(BO Unless this option is set \*(UA will pass some well known
6995 standard command line options to the defined
6997 program, see there for more.
7000 .It Va sendmail-progname
7001 Many systems use a so-called
7003 environment to ensure compatibility with
7005 This works by inspecting the name that was used to invoke the mail
7007 If this variable is set then the mailwrapper (the program that is
7008 actually executed when calling
7010 will treat its contents as that name.
7016 \*(BO When sending a message wait until the MTA (including the builtin
7017 SMTP one) exits before accepting further commands.
7019 with this variable set errors reported by the MTA will be recognizable!
7020 If the MTA returns a non-zero exit status,
7021 the exit status of \*(ua will also be non-zero.
7025 \*(BO Setting this option causes \*(UA to start at the last message
7026 instead of the first one when opening a mail folder.
7030 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7031 address in the header field summary and in message specifications.
7035 \*(BO Causes the recipient of the message to be shown in the header
7036 summary if the message was sent by the user.
7040 A string for use with the
7046 A string for use with the
7052 Must correspond to the name of a readable file if set.
7053 The file's content is then appended to each singlepart message
7054 and to the first part of each multipart message.
7055 Be warned that there is no possibility to edit the signature for an
7059 .It Va skipemptybody
7060 \*(BO If an outgoing message does not contain any text in its first or
7061 only message part, do not send it but discard it silently (see also the
7067 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7068 Enhanced Mail) format for verification of S/MIME signed messages.
7071 .It Va smime-ca-file
7072 \*(OP Specifies a file with CA certificates in PEM format for
7073 verification of S/MIME signed messages.
7076 .It Va smime-cipher-USER@HOST , smime-cipher
7077 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7078 messages (for the specified account).
7079 RFC 5751 mandates a default of
7082 Possible values are (case-insensitive and) in decreasing cipher strength:
7090 (DES EDE3 CBC, 168 bits; default if
7092 isn't available) and
7096 The actually available cipher algorithms depend on the cryptographic
7097 library that \*(UA uses.
7098 \*(OP Support for more cipher algorithms may be available through
7099 dynamic loading via, e.g.,
7100 .Xr EVP_get_cipherbyname 3
7101 (OpenSSL) if \*(UA has been compiled to support this.
7104 .It Va smime-crl-dir
7105 \*(OP Specifies a directory that contains files with CRLs in PEM format
7106 to use when verifying S/MIME messages.
7109 .It Va smime-crl-file
7110 \*(OP Specifies a file that contains a CRL in PEM format to use when
7111 verifying S/MIME messages.
7114 .It Va smime-encrypt-USER@HOST
7115 \*(OP If this variable is set, messages send to the given receiver are
7116 encrypted before sending.
7117 The value of the variable must be set to the name of a file that
7118 contains a certificate in PEM format.
7120 If a message is sent to multiple recipients,
7121 each of them for whom a corresponding variable is set will receive an
7122 individually encrypted message;
7123 other recipients will continue to receive the message in plain text
7125 .Va smime-force-encryption
7127 It is recommended to sign encrypted messages, i.e., to also set the
7132 .It Va smime-force-encryption
7133 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7136 .It Va smime-no-default-ca
7137 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7142 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7143 and include the user's certificate as a MIME attachment.
7144 Signing a message enables a recipient to verify that the sender used
7145 a valid certificate,
7146 that the email addresses in the certificate match those in the message
7147 header and that the message content has not been altered.
7148 It does not change the message text,
7149 and people will be able to read the message as usual.
7151 .Va smime-sign-cert , smime-sign-include-certs
7153 .Va smime-sign-message-digest .
7155 .Mx Va smime-sign-cert
7156 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7157 \*(OP Points to a file in PEM format.
7158 For the purpose of signing and decryption this file needs to contain the
7159 user's private key as well as his certificate.
7163 is always derived from the value of
7165 (or, if that contains multiple addresses,
7167 For the purpose of encryption the recipient's public encryption key
7168 (certificate) is expected; the command
7170 can be used to save certificates of signed messages (the section
7171 .Sx "Signed and encrypted messages with S/MIME"
7172 gives some details).
7173 This mode of operation is usually driven by the specialized form.
7175 When decrypting messages the account is derived from the recipient
7180 of the message, which are searched for addresses for which such
7182 \*(UA always uses the first address that matches,
7183 so if the same message is sent to more than one of the user's addresses
7184 using different encryption keys, decryption might fail.
7186 .Mx Va smime-sign-include-certs
7187 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7188 \*(OP If used, this is supposed to a consist of a comma-separated list
7189 of files, each of which containing a single certificate in PEM format to
7190 be included in the S/MIME message in addition to the
7193 This is most useful for long certificate chains if it is desired to aid
7194 the receiving party's verification process.
7195 Note that top level certificates may also be included in the chain but
7196 don't play a role for verification.
7198 .Va smime-sign-cert .
7199 Remember that for this
7201 refers to the variable
7203 (or, if that contains multiple addresses,
7206 .Mx Va smime-sign-message-digest
7207 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7208 \*(OP Specifies the message digest to use when signing S/MIME messages.
7209 RFC 5751 mandates a default of
7211 Possible values are (case-insensitive and) in decreasing cipher strength:
7219 The actually available message digest algorithms depend on the
7220 cryptographic library that \*(UA uses.
7221 \*(OP Support for more message digest algorithms may be available
7222 through dynamic loading via, e.g.,
7223 .Xr EVP_get_digestbyname 3
7224 (OpenSSL) if \*(UA has been compiled to support this.
7225 Remember that for this
7227 refers to the variable
7229 (or, if that contains multiple addresses,
7235 \*(OP Normally \*(UA invokes the program defined via
7237 to transfer messages, as described in
7238 .Sx "On sending mail, and non-interactive mode" .
7241 variable will instead cause SMTP network connections be made to the
7242 server specified therein in order to directly submit the message.
7243 \*(UA knows about three different
7244 .Dq SMTP protocols :
7246 .Bl -bullet -compact
7248 The plain SMTP protocol (RFC 5321) that normally lives on the
7249 server port 25 and requires setting the
7250 .Va smtp-use-starttls
7251 variable to enter a SSL/TLS encrypted session state.
7252 Assign a value like \*(IN
7253 .Ql [smtp://][user[:password]@]server[:port]
7255 .Ql [smtp://]server[:port] )
7256 to choose this protocol.
7258 Then the so-called SMTPS which is supposed to live on server port 465
7259 and is automatically SSL/TLS secured.
7260 Unfortunately it never became a standardized protocol and may thus not
7261 be supported by your hosts network service database
7262 \(en in fact the port number has already been reassigned to other
7265 SMTPS is nonetheless a commonly offered protocol and thus can be
7266 chosen by assigning a value like \*(IN
7267 .Ql smtps://[user[:password]@]server[:port]
7269 .Ql smtps://server[:port] ) ;
7270 due to the mentioned problems it is usually necessary to explicitly
7275 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7276 lives on server port 587 and is practically identically to the SMTP
7277 protocol from \*(UA's point of view beside that; it requires setting the
7278 .Va smtp-use-starttls
7279 variable to enter a SSL/TLS secured session state.
7280 Assign a value like \*(IN
7281 .Ql submission://[user[:password]@]server[:port]
7283 .Ql submission://server[:port] ) .
7286 For more on credentials etc. please see
7287 .Sx "On URL syntax and credential lookup" .
7288 The SMTP transfer is executed in a child process, which runs
7289 asynchronously unless either the
7294 If it receives a TERM signal, it will abort and save the message to
7299 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7300 \*(OP Variable chain that sets the SMTP authentication method.
7307 as well as the \*(OPal methods
7313 method doesn't need any user credentials,
7315 requires a user name and all other methods require a user name and
7323 .Va smtp-auth-password
7325 .Va smtp-auth-user ) .
7330 .Va smtp-auth-USER@HOST :
7331 may override dependend on sender address in the variable
7334 .It Va smtp-auth-password
7335 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7336 If the authentication method requires a password, but neither
7337 .Va smtp-auth-password
7339 .Va smtp-auth-password-USER@HOST
7341 \*(UA will ask for a password on the user's terminal.
7343 .It Va smtp-auth-password-USER@HOST
7345 .Va smtp-auth-password
7346 for specific values of sender addresses, dependent upon the variable
7349 .It Va smtp-auth-user
7350 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7351 If the authentication method requires a user name, but neither
7354 .Va smtp-auth-user-USER@HOST
7356 \*(UA will ask for a user name on the user's terminal.
7358 .It Va smtp-auth-user-USER@HOST
7361 for specific values of sender addresses, dependent upon the variable
7365 .It Va smtp-hostname
7366 \*(IN Normally \*(UA uses the variable
7368 to derive the necessary
7370 information to issue a
7375 can be used to use the
7377 from the SMTP account
7384 from the content of this variable (or, if that is the empty string,
7386 or the local hostname as a last resort).
7387 This often allows using an address that is itself valid but hosted by
7388 a provider other than which (in
7390 is about to send the message.
7391 Setting this variable also influences the generated
7394 .Mx Va smtp-use-starttls
7395 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7396 \*(BO\*(OP Causes \*(UA to issue a
7398 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7399 transport layer security.
7403 .It Va spam-interface
7404 \*(OP In order to use any of the spam-related commands (like, e.g.,
7406 the desired spam interface must be defined by setting this variable.
7407 Please refer to the manual section
7409 for the complete picture of spam handling in \*(UA.
7410 All or none of the following interfaces may be available:
7412 .Bl -tag -width ".It Ql _ilte_"
7418 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7420 Different to the generic filter interface \*(UA will automatically add
7421 the correct arguments for a given command and has the necessary
7422 knowledge to parse the program's output.
7425 will have been compiled into the \*(UA binary if
7430 Shall it be necessary to define a specific connection type (rather than
7431 using a configuration file for that), the variable
7433 can be used as in, e.g.,
7434 .Ql -d server.example.com -p 783 .
7435 It is also possible to specify a per-user configuration via
7437 Note that this interface doesn't inspect the
7439 flag of a message for the command
7443 \*(UA will directly communicate with the
7449 stream socket as specified in
7451 It is possible to specify a per-user configuration via
7455 generic spam filter support via freely configurable hooks.
7456 This interface is ment for programs like
7460 and requires according behaviour in respect to the hooks' exit
7461 status for at least the command
7464 meaning a message is spam,
7468 for unsure and any other return value indicating a hard error);
7469 since the hooks can include shell code snippets diverting behaviour
7470 can be intercepted as necessary.
7472 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7475 .Va spamfilter-spam ;
7478 contains examples for some programs.
7479 The process environment of the hooks will have the variables
7480 .Ev NAIL_TMPDIR , TMPDIR
7482 .Ev NAIL_FILENAME_GENERATED
7484 Note that spam score support for
7486 isn't supported unless the \*(OPtional regular expression support is
7488 .Va spamfilter-rate-scanscore
7495 \*(OP Messages that exceed this size won't be passed through to the
7497 .Va spam-interface .
7498 The default is 420000 bytes.
7501 .It Va spamc-command
7502 \*(OP The path to the
7506 .Va spam-interface .
7507 Note that the path is not expanded, but used
7509 A fallback path will have been compiled into the \*(UA binary if the
7510 executable had been found during compilation.
7513 .It Va spamc-arguments
7514 \*(OP Even though \*(UA deals with most arguments for the
7517 automatically, it may at least sometimes be desirable to specifiy
7518 connection-related ones via this variable, e.g.,
7519 .Ql -d server.example.com -p 783 .
7523 \*(OP Specify a username for per-user configuration files for the
7525 .Va spam-interface .
7526 If this is set to the empty string then \*(UA will use the name of the
7532 \*(OP Specify the path of the
7534 domain socket on which
7536 listens for connections for the
7538 .Va spam-interface .
7539 Note that the path is not expanded, but used
7544 \*(OP Specify a username for per-user configuration files for the
7546 .Va spam-interface .
7547 If this is set to the empty string then \*(UA will use the name of the
7556 .It Va spamfilter-ham , spamfilter-noham , \
7557 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7558 \*(OP Command and argument hooks for the
7560 .Va spam-interface .
7563 contains examples for some programs.
7566 .It Va spamfilter-rate-scanscore
7567 \*(OP Because of the generic nature of the
7570 spam scores are not supported for it by default, but if the \*(OPtional
7571 regular expression support is available then setting this variable can
7572 be used to overcome this restriction.
7573 It is interpreted as follows: first a number (digits) is parsed that
7574 must be followed by a semicolon
7576 and an extended regular expression.
7577 Then the latter is used to parse the first output line of the
7579 hook, and, in case the evaluation is successful, the group that has been
7580 specified via the number is interpreted as a floating point scan score.
7584 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7585 Enhanced Mail) for verification of of SSL/TLS server certificates.
7587 .Xr SSL_CTX_load_verify_locations 3
7588 for more information.
7592 \*(OP Specifies a file with CA certificates in PEM format for
7593 verification of SSL/TLS server certificates.
7595 .Xr SSL_CTX_load_verify_locations 3
7596 for more information.
7599 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7600 \*(OP Variable chain that sets the file name for a SSL/TLS client
7601 certificate required by some servers.
7602 This is a direct interface to the
7606 function of the OpenSSL library, if available.
7608 .Mx Va ssl-cipher-list
7609 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7610 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7611 This is a direct interface to the
7615 function of the OpenSSL library, if available; see
7617 for more information.
7618 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7620 specific cipher (protocol standards ship with a list of acceptable
7621 ciphers), possibly cramped to what the actually used SSL/TLS library
7622 supports \(en the manual section
7623 .Sx "An example configuration"
7624 also contains a SSL/TLS use case.
7627 .It Va ssl-config-file
7628 \*(OP If this variable is set \*(UA will call
7629 .Xr CONF_modules_load_file 3
7630 to allow OpenSSL to be configured according to the host system wide
7632 If a non-empty value is given then this will be used to specify the
7633 configuration file to be used instead of the global OpenSSL default;
7634 note that in this case it is an error if the file cannot be loaded.
7635 The application name will always be passed as
7640 \*(OP Specifies a file that contains a CRL in PEM format to use when
7641 verifying SSL/TLS server certificates.
7645 \*(OP Specifies a directory that contains files with CRLs in PEM format
7646 to use when verifying SSL/TLS server certificates.
7649 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7650 \*(OP Variable chain that sets the file name for the private key of
7651 a SSL/TLS client certificate.
7652 If unset, the name of the certificate file is used.
7653 The file is expected to be in PEM format.
7654 This is a direct interface to the
7658 function of the OpenSSL library, if available.
7661 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7663 \*(OB Please use the newer and more flexible
7665 instead: if both values are set,
7667 will take precedence!
7668 Can be set to the following values, the actually used
7670 specification to which it is mapped is shown in parenthesis:
7672 .Pf ( Ql -ALL, TLSv1.2 ) ,
7674 .Pf ( Ql -ALL, TLSv1.1 ) ,
7676 .Pf ( Ql -ALL, TLSv1 )
7679 .Pf ( Ql -ALL, SSLv3 ) ;
7684 and thus includes the SSLv3 protocol.
7685 Note that SSLv2 is no longer supported at all.
7688 .It Va ssl-no-default-ca
7689 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7693 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7694 \*(OP Specify the used SSL/TLS protocol.
7695 This is a direct interface to the
7699 function of the OpenSSL library, if available;
7700 otherwise an \*(UA internal parser is used which understands the
7701 following subset of (case-insensitive) command strings:
7707 as well as the special value
7709 Multiple specifications may be given via a comma-separated list which
7710 ignores any whitespace.
7713 plus prefix will enable a protocol, a
7715 minus prefix will disable it, so that
7717 will enable only the TLSv1.2 protocol.
7719 It depends upon the used TLS/SSL library which protocols are actually
7720 supported and which protocols are used if
7722 is not set, but note that SSLv2 is no longer supported at all and
7724 Especially for older protocols explicitly securing
7726 may be worthwile, see
7727 .Sx "An example configuration" .
7731 \*(OP Gives the pathname to an entropy daemon socket, see
7733 Not all SSL/TLS libraries support this.
7736 .It Va ssl-rand-file
7737 \*(OP Gives the pathname to a file with entropy data, see
7738 .Xr RAND_load_file 3 .
7739 If the file is a regular file writable by the invoking user,
7740 new data is written to it after it has been loaded.
7743 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7744 \*(OP Variable chain that sets the action to be performed if an error
7745 occurs during SSL/TLS server certificate validation.
7746 Valid (case-insensitive) values are
7748 (fail and close connection immediately),
7750 (ask whether to continue on standard input),
7752 (print a warning and continue),
7754 (do not perform validation).
7760 If only set without an assigned value, then this option inhibits the
7765 header fields that include obvious references to \*(UA.
7766 There are two pitfalls associated with this:
7767 First, the message id of outgoing messages is not known anymore.
7768 Second, an expert may still use the remaining information in the header
7769 to track down the originating mail user agent.
7774 suppression doesn't occur.
7778 \*(BY\*(OP If terminal capability queries are supported and this option
7779 is set then \*(UA will try to switch to the
7780 .Dq alternate screen
7781 when in interactive mode, so that the terminal will go back to the
7782 normal screen, leaving all the text there intact, when \*(UA exits.
7785 even when supported for this to produce appealing results the used
7787 and possibly configured
7788 .Va pipe-TYPE/SUBTYPE
7789 applications that take control over the terminal need to have
7790 corresponding support and must be configured accordingly, too, e.g., the
7792 pager should be driven with the
7798 If defined, gives the number of lines of a message to be printed out
7799 with the top command; normally, the first five lines are printed.
7803 The character set of the terminal \*(UA operates on,
7804 and the one and only supported character set that \*(UA can use if no
7805 character set conversion capabilities have been compiled into it,
7806 in which case it defaults to ISO-8859-1 unless it can deduce a value
7810 Refer to the section
7811 .Sx "Character sets"
7812 for the complete picture about character sets.
7815 .It Va user-HOST , user
7816 \*(IN Variable chain that sets a global fallback user name, which is
7817 used in case none has been given in the protocol and account-specific
7819 This variable defaults to the value of
7824 \*(BO Setting this option enables upward compatibility with \*(UA
7825 version 15.0 in respect to which configuration options are available and
7826 how they are handled.
7827 This manual uses \*(IN and \*(OU to refer to the new and the old way of
7828 doing things, respectively.
7832 \*(BO Setting this option, also controllable via the command line option
7834 causes \*(UA to be more verbose, e.g., it will display obsoletion
7835 warnings and SSL/TLS certificate chains.
7836 Even though marked \*(BO this option may be set twice in order to
7837 increase the level of verbosity even more, in which case even details of
7838 the actual message delivery and protocol conversations are shown.
7841 is sufficient to disable verbosity as such.
7847 .It Va version , version-major , version-minor , version-update
7848 \*(RO \*(UA version information: the first variable contains a string
7849 containing the complete version identification \(en this is identical to
7850 the output of the command
7852 The latter three contain only digits: the major, minor and update
7856 .It Va writebackedited
7857 If this variable is set messages modified using the
7861 commands are written back to the current folder when it is quit;
7862 it is only honoured for writable folders in MBOX format, though.
7863 Note that the editor will be pointed to the raw message content in that
7864 case, i.e., neither MIME decoding nor decryption will have been
7865 performed, and proper RFC 4155
7867 quoting of newly added or edited content is also left as an excercise to
7871 .\" }}} (INTERNAL VARIABLES)
7874 .\" .Sh ENVIRONMENT {{{
7878 .Dq environment variable
7879 should be considered an indication that the following variables are
7880 either standardized as being vivid parts of process environments, or
7881 are commonly found in there.
7882 The process environment is inherited from the
7884 once \*(UA is started, and unless otherwise explicitly noted variables
7885 in there integrate into the normal handling of
7886 .Sx "INTERNAL VARIABLES" ,
7887 from \*(UAs point of view, i.e., they can be
7889 as such in resource files and need not necessarily come from the process
7890 environment and be managed via
7894 E.g., the following example, applicable to a POSIX shell, sets the
7896 environment variable for \*(UA only, and beforehand exports the
7898 in order to affect any further processing in the running shell:
7900 .Bd -literal -offset indent
7901 $ EDITOR="vim -u ${HOME}/.vimrc"
7903 $ COLUMNS=80 \*(ua -R
7906 .Bl -tag -width ".It Ev _AILR_"
7909 The user's preferred width in column positions for the terminal screen
7911 Queried and used once on program startup.
7915 The name of the file to use for saving aborted messages if
7917 is set; this defaults to
7925 Pathname of the text editor to use in the
7929 .Sx "TILDE ESCAPES" .
7930 A default editor is used if this value is not defined.
7934 The user's home directory.
7935 This variable is only used when it resides in the process environment.
7938 to update the value at runtime.
7945 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
7949 .Sx "Character sets" .
7953 The user's preferred number of lines on a page or the vertical screen
7954 or window size in lines.
7955 Queried and used once on program startup.
7959 Pathname of the directory lister to use in the
7961 command when operating on local mailboxes.
7964 (path search through
7969 Is used as the user's mailbox, if set.
7970 Otherwise, a system-dependent default is used.
7971 Supports a logical subset of the special conventions that are documented
7980 \*(OP Overrides the default path search for
7981 .Sx "The Mailcap files" ,
7982 which is defined in the standard RFC 1524 as
7983 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
7984 .\" TODO we should have a mailcaps-default virtual RDONLY option!
7985 (\*(UA makes it a configuration option, however.)
7986 Note this is not a search path, but a path search.
7990 Is used as a startup file instead of
7993 When \*(UA scripts are invoked on behalf of other users,
7994 this variable should be set to
7996 to avoid side-effects from reading their configuration files.
7997 This variable is only used when it resides in the process environment.
8001 The name of the user's mbox file.
8002 A logical subset of the special conventions that are documented for the
8007 The fallback default is
8012 Traditionally this secondary mailbox is used as the file to save
8013 messages from the system mailbox that have been read.
8015 .Sx "Message states" .
8018 .It Ev NAIL_NO_SYSTEM_RC
8019 If this variable is set then reading of
8021 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8022 had been started up with the option
8024 This variable is only used when it resides in the process environment.
8028 \*(IN\*(OP This variable overrides the default location of the user's
8034 The value to put into the
8036 field of the message header.
8040 Pathname of the program to use in the more command or when the
8043 The default paginator is
8045 (path search through
8050 A list of directories that is searched by the shell when looking for
8051 commands (as such only recognized in the process environment).
8055 The shell to use for the commands
8061 and when starting subprocesses.
8062 A default shell is used if this option is not defined.
8066 \*(OP The terminal type for which output is to be prepared.
8070 Used as directory for temporary files instead of
8073 This variable is only used when it resides in the process environment.
8076 to update the value at runtime.
8080 Force identification as the given user, i.e., identical to the
8082 command line option.
8083 This variable is only used when it resides in the process environment.
8086 to update the value at runtime, but note that doing so won't trigger any
8087 of those validation checks that were performed on program startup (again).
8091 Pathname of the text editor to use in the
8095 .Sx "TILDE ESCAPES" .
8103 .Bl -tag -width ".It Pa _etc/mime.type_"
8105 File giving initial commands.
8108 System wide initialization file.
8112 \*(OP Personal MIME type handler definition file, see
8113 .Sx "The Mailcap files" .
8114 (RFC 1524 location, the actual path is a configuration option.)
8118 \*(OP System wide MIME type handler definition file, see
8119 .Sx "The Mailcap files" .
8120 (RFC 1524 location, the actual path is a configuration option.)
8123 .It Pa ~/.mime.types
8124 Personal MIME types, see
8125 .Sx "The mime.types files" .
8128 .It Pa /etc/mime.types
8129 System wide MIME types, see
8130 .Sx "The mime.types files" .
8134 \*(IN\*(OP The default location of the users
8136 file \(en the section
8137 .Sx "The .netrc file"
8138 documents the file format.
8141 .\" .Ss "The mime.types files" {{{
8142 .Ss "The mime.types files"
8144 When sending messages \*(UA tries to determine the content type of all
8146 When displaying message content or attachments \*(UA uses the content
8147 type to decide wether it can directly display data or wether it needs to
8148 deal with content handlers.
8149 It learns about MIME types and how to treat them by reading
8151 files, the loading of which can be controlled by setting the variable
8152 .Va mimetypes-load-control .
8155 can also be used to deal with MIME types.)
8157 files have the following syntax:
8160 .Dl type/subtype extension [extension ...]
8165 are strings describing the file contents, and one or multiple
8167 s, separated by whitespace, name the part of a filename starting after
8168 the last dot (of interest).
8169 Comments may be introduced anywhere on a line with a number sign
8171 causing the remaining line to be discarded.
8173 \*(UA also supports an extended, non-portable syntax in specially
8174 crafted files, which can be loaded via the alternative value syntax of
8175 .Va mimetypes-load-control
8176 and prepends an optional
8180 .Dl [type-marker ]type/subtype extension [extension ...]
8183 The following type markers are supported:
8186 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8188 Treat message parts with this content as plain text.
8193 Treat message parts with this content as HTML tagsoup.
8194 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8195 the content as plain text instead.
8199 but instead of falling back to plain text require an explicit content
8200 handler to be defined.
8205 for sending messages:
8207 .Va mime-allow-text-controls ,
8208 .Va mimetypes-load-control .
8209 For reading etc. messages:
8210 .Sx "HTML mail and MIME attachments" ,
8211 .Sx "The Mailcap files" ,
8213 .Va mime-counter-evidence ,
8214 .Va mimetypes-load-control ,
8215 .Va pipe-TYPE/SUBTYPE ,
8216 .Va pipe-EXTENSION .
8219 .\" .Ss "The Mailcap files" {{{
8220 .Ss "The Mailcap files"
8223 .Dq User Agent Configuration Mechanism
8224 which \*(UA \*(OPally supports.
8225 It defines a file format to be used to inform mail user agent programs
8226 about the locally-installed facilities for handling various data
8227 formats, i.e., about commands and how they can be used to display, edit
8228 etc. MIME part contents, as well as a default path search that includes
8229 multiple possible locations of
8233 environment variable that can be used to overwrite that (repeating here
8234 that it is not a search path, but instead a path search specification).
8235 Any existing files will be loaded in sequence, appending any content to
8236 the list of MIME type handler directives.
8240 files consist of a set of newline separated entries.
8241 Comment lines start with a number sign
8243 (in the first column!) and are ignored.
8244 Empty lines are also ignored.
8245 All other lines form individual entries that must adhere to the syntax
8247 To extend a single entry (not comment) its line can be continued on
8248 follow lines if newline characters are
8250 by preceding them with the backslash character
8252 The standard doesn't specify how leading whitespace of follow lines is
8253 to be treated, therefore \*(UA retains it.
8257 entries consist of a number of semicolon
8259 separated fields, and the backslash
8261 character can be used to escape any following character including
8262 semicolon and itself.
8263 The first two fields are mandatory and must occur in the specified
8264 order, the remaining fields are optional and may appear in any order.
8265 Leading and trailing whitespace of content is ignored (removed).
8268 The first field defines the MIME
8270 the entry is about to handle (case-insensitively, and no backslash
8271 escaping is possible in this field).
8272 If the subtype is specified as an asterisk
8274 the entry is ment to match all subtypes of the named type, e.g.,
8276 would match any audio type.
8277 The second field defines the shell command which shall be used to
8279 MIME parts of the given type; it is implicitly called the
8286 shell commands message (MIME part) data is passed via standard input
8287 unless the given shell command includes one or more instances of the
8290 in which case these instances will be replaced with a temporary filename
8291 and the data will have been stored in the file that is being pointed to.
8294 shell commands data is assumed to be generated on standard output unless
8295 the given command includes (one ore multiple)
8297 In any case any given
8299 format is replaced with a(n already) properly quoted filename.
8300 Note that when a command makes use of a temporary file via
8302 then \*(UA will remove it again, as if the
8303 .Cd x-mailx-tmpfile ,
8304 .Cd x-mailx-tmpfile-fill
8306 .Cd x-mailx-tmpfile-unlink
8307 flags had been set; see below for more.
8310 The optional fields either define a shell command or an attribute (flag)
8311 value, the latter being a single word and the former being a keyword
8312 naming the field followed by an equals sign
8314 succeeded by a shell command, and as usual for any
8316 content any whitespace surrounding the equals sign will be removed, too.
8317 Optional fields include the following:
8320 .Bl -tag -width textualnewlines
8322 A program that can be used to compose a new body or body part in the
8329 field, but is to be used when the composing program needs to specify the
8331 header field to be applied to the composed data.
8335 A program that can be used to edit a body or body part in the given
8340 A program that can be used to print a message or body part in the given
8345 Specifies a program to be run to test some condition, e.g., the machine
8346 architecture, or the window system in use, to determine whether or not
8347 this mailcap entry applies.
8348 If the test fails, a subsequent mailcap entry should be sought; also see
8349 .Cd x-mailx-test-once .
8351 .It Cd needsterminal
8352 This flag field indicates that the given shell command must be run on
8353 an interactive terminal.
8354 \*(UA will temporarily release the terminal to the given command in
8355 interactive mode, in non-interactive mode this entry will be entirely
8356 ignored; this flag implies
8357 .Cd x-mailx-noquote .
8359 .It Cd copiousoutput
8360 A flag field which indicates that the output of the
8362 command will be an extended stream of textual output that can be
8363 (re)integrated into \*(UA's normal visual display.
8364 It is mutually exclusive with
8367 .Cd x-mailx-always .
8369 .It Cd textualnewlines
8370 A flag field which indicates that this type of data is line-oriented and
8373 all newlines should be converted to canonical form (CRLF) before
8374 encoding, and will be in that form after decoding.
8378 This field gives a file name format, in which
8380 will be replaced by a random string, the joined combination of which
8381 will be used as the filename denoted by
8382 .Ev NAIL_FILENAME_TEMPORARY .
8383 One could specify that a GIF file being passed to an image viewer should
8384 have a name ending in
8387 .Ql nametemplate=%s.gif .
8388 Note that \*(UA ignores the name template unless that solely specifies
8389 a filename suffix that consists of (ASCII) alphabetic and numeric
8390 characters, the underscore and dot only.
8393 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8394 icon to be used to visually denote the presence of this kind of data.
8395 This field is not used by \*(UA.
8398 A textual description that describes this type of data.
8400 .It Cd x-mailx-always
8401 Extension flag field that denotes that the given
8403 command shall be executed even if multiple messages will be displayed
8405 Normally messages which require external viewers that produce output
8406 which doesn't integrate into \*(UA's visual display (i.e., don't have
8408 set) have to be addressed directly and individually.
8409 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8412 .It Cd x-mailx-even-if-not-interactive
8413 An extension flag test field \(em by default handlers without
8415 are entirely ignored in non-interactive mode, but if this flag is set
8416 then their use will be considered.
8417 It is an error if this flag is set for commands that use the flag
8420 .It Cd x-mailx-noquote
8421 An extension flag field that indicates that even a
8424 command shall not be used to generate message quotes
8425 (as it would be by default).
8427 .It Cd x-mailx-async
8428 Extension flag field that denotes that the given
8430 command shall be executed asynchronously, without blocking \*(UA.
8431 Cannot be used in conjunction with
8434 .It Cd x-mailx-test-once
8435 Extension flag which denotes wether the given
8437 command shall be evaluated once only and the (boolean) result be cached.
8438 This is handy if some global unchanging condition is to be queried, like
8439 .Dq running under the X Window System .
8441 .It Cd x-mailx-tmpfile
8442 Extension flag field that requests creation of a zero-sized temporary
8443 file, the name of which is to be placed in the environment variable
8444 .Ev NAIL_FILENAME_TEMPORARY .
8445 It is an error to use this flag with commands that include a
8449 .It Cd x-mailx-tmpfile-fill
8450 Normally the MIME part content is passed to the handler via standard
8451 input; if this flag is set then the data will instead be written into
8453 .Cd x-mailx-tmpfile .
8454 In order to cause deletion of the temporary file you will have to set
8455 .Cd x-mailx-tmpfile-unlink
8457 It is an error to use this flag with commands that include a
8461 .It Cd x-mailx-tmpfile-unlink
8462 Extension flag field that requests that the temporary file shall be
8463 deleted automatically when the command loop is entered again at latest.
8464 (Don't use this for asynchronous handlers.)
8465 It is an error to use this flag with commands that include a
8467 format, or without also setting
8470 .Cd x-mailx-tmpfile-fill .
8472 .It Cd x-mailx-tmpfile-keep
8475 implies the three tmpfile related flags above, but if you want, e.g.,
8477 and deal with the temporary file yourself, you can add in this flag to
8479 .Cd x-mailx-tmpfile-unlink .
8484 The standard includes the possibility to define any number of additional
8485 entry fields, prefixed by
8487 Flag fields apply to the entire
8489 entry \(em in some unusual cases, this may not be desirable, but
8490 differentiation can be accomplished via separate entries, taking
8491 advantage of the fact that subsequent entries are searched if an earlier
8492 one does not provide enough information.
8495 command needs to specify the
8499 command shall not, the following will help out the latter (with enabled
8503 level \*(UA will show informations about handler evaluation):
8505 .Bd -literal -offset indent
8506 application/postscript; ps-to-terminal %s; needsterminal
8507 application/postscript; ps-to-terminal %s; compose=idraw %s
8511 In fields any occurrence of the format string
8513 will be replaced by the
8516 Named parameters from the
8518 field may be placed in the command execution line using
8520 followed by the parameter name and a closing
8523 The entire parameter should appear as a single command line argument,
8524 regardless of embedded spaces; thus:
8526 .Bd -literal -offset indent
8528 Content-type: multipart/mixed; boundary=42
8531 multipart/*; /usr/local/bin/showmulti \e
8532 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8534 # Executed shell command
8535 /usr/local/bin/showmulti multipart/mixed 42
8539 .\" TODO v15: Mailcap: %n,%F
8540 Note that \*(UA doesn't support handlers for multipart MIME parts as
8541 shown in this example (as of today).
8542 \*(UA doesn't support the additional formats
8546 An example file, also showing how to properly deal with the expansion of
8548 which includes any quotes that are necessary to make it a valid shell
8549 argument by itself and thus will cause undesired behaviour when placed
8550 in additional user-provided quotes:
8552 .Bd -literal -offset indent
8554 text/richtext; richtext %s; copiousoutput
8556 text/x-perl; perl -cWT %s
8560 trap "rm -f ${infile}" EXIT\e; \e
8561 trap "exit 75" INT QUIT TERM\e; \e
8563 x-mailx-async; x-mailx-tmpfile-keep
8565 application/*; echo "This is \e"%t\e" but \e
8566 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
8567 copiousoutput; x-mailx-noquote
8572 .Sx "HTML mail and MIME attachments" ,
8573 .Sx "The mime.types files" ,
8576 .Va mime-counter-evidence ,
8577 .Va pipe-TYPE/SUBTYPE ,
8578 .Va pipe-EXTENSION .
8581 .\" .Ss "The .netrc file" {{{
8582 .Ss "The .netrc file"
8586 file contains user credentials for machine accounts.
8587 The default location in the user's
8589 directory may be overridden by the
8591 environment variable.
8592 The file consists of space, tabulator or newline separated tokens.
8593 \*(UA implements a parser that supports a superset of the original BSD
8594 syntax, but users should nonetheless be aware of portability glitches
8595 of that file format, shall their
8597 be usable across multiple programs and platforms:
8600 .Bl -bullet -compact
8602 BSD doesn't support single, but only double quotation marks, e.g.,
8603 .Ql password="pass with spaces" .
8605 BSD (only?) supports escaping of single characters via a backslash
8606 (e.g., a space can be escaped via
8608 in- as well as outside of a quoted string.
8610 BSD doesn't require the final quotation mark of the final user input token.
8612 At least Hewlett-Packard seems to support a format which also allows
8613 tokens to be separated with commas \(en this format is not supported!
8615 Whereas other programs may require that the
8617 file is accessible by only the user if it contains a
8623 \*(UA will always require these strict permissions.
8627 Of the following list of supported tokens \*(UA only uses (and caches)
8632 At runtime the command
8634 can be used to control \*(UAs
8638 .Bl -tag -width password
8639 .It Cd machine Ar name
8640 The hostname of the entries' machine, lowercase-normalized by \*(UA
8642 Any further file content, until either end-of-file or the occurrence
8647 first-class token is bound (only related) to the machine
8650 As an extension that shouldn't be the cause of any worries
8651 \*(UA supports a single wildcard prefix for
8653 .Bd -literal -offset indent
8654 machine *.example.com login USER password PASS
8655 machine pop3.example.com login USER password PASS
8656 machine smtp.example.com login USER password PASS
8662 .Ql pop3.example.com ,
8666 .Ql local.smtp.example.com .
8667 Note that in the example neither
8668 .Ql pop3.example.com
8670 .Ql smtp.example.com
8671 will be matched by the wildcard, since the exact matches take
8672 precedence (it is however faster to specify it the other way around).
8677 except that it is a fallback entry that is used shall none of the
8678 specified machines match; only one default token may be specified,
8679 and it must be the last first-class token.
8681 .It Cd login Ar name
8682 The user name on the remote machine.
8684 .It Cd password Ar string
8685 The user's password on the remote machine.
8687 .It Cd account Ar string
8688 Supply an additional account password.
8689 This is merely for FTP purposes.
8691 .It Cd macdef Ar name
8693 A macro is defined with the specified
8695 it is formed from all lines beginning with the next line and continuing
8696 until a blank line is (consecutive newline characters are) encountered.
8699 entries cannot be utilized by multiple machines, too, but must be
8700 defined following the
8702 they are intended to be used with.)
8705 exists, it is automatically run as the last step of the login process.
8706 This is merely for FTP purposes.
8713 .\" .Sh EXAMPLES {{{
8716 .\" .Ss "An example configuration" {{{
8717 .Ss "An example configuration"
8719 .Bd -literal -offset indent
8720 # This example assumes v15.0 compatibility mode
8723 # Where are the up-to-date SSL certificates?
8724 #set ssl-ca-dir=/etc/ssl/certs
8725 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8727 # (Since we manage up-to-date ones explicitly, don't use any,
8728 # possibly outdated, default certificates shipped with OpenSSL
8729 set ssl-no-default-ca
8731 # Don't use protocols older than TLS v1.2.
8732 # Change this only when the remote server doesn't support it:
8733 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
8734 # such explicit exceptions, then
8735 set ssl-protocol="-ALL,+TLSv1.2"
8737 # Explicitly define the list of ciphers, which may improve security,
8738 # especially with protocols older than TLS v1.2. See ciphers(1).
8739 # Hint: it is important to include "@STRENGTH": only with it the
8740 # final list will be sorted by algorithm strength.
8741 # This is an example: in reality it is possibly best to only use
8742 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
8743 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
8744 !MD5:!RC4:!EXPORT:@STRENGTH"
8746 # Request strict transport security checks!
8747 set ssl-verify=strict
8749 # Essential setting: select allowed character sets
8750 set sendcharsets=utf-8,iso-8859-1
8752 # A very kind option: when replying to a message, first try to
8753 # use the same encoding that the original poster used herself!
8754 set reply-in-same-charset
8756 # When replying to or forwarding a message the comment and name
8757 # parts of email addresses are removed unless this variable is set
8760 # When sending messages, wait until the Mail-Transfer-Agent finishs.
8761 # Only like this you'll be able to see errors reported through the
8762 # exit status of the MTA (including the builtin SMTP one)!
8765 # Only use builtin MIME types, no mime.types(5) files
8766 set mimetypes-load-control
8768 # Default directory where we act in (relative to $HOME)
8770 # A leading "+" (often) means: under *folder*
8771 # *record* is used to save copies of sent messages
8772 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
8774 # Make "file mymbox" and "file myrec" go to..
8775 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
8777 # Not really optional, e.g., for S/MIME
8778 set from="Your Name <youremail@domain>"
8780 # It may be necessary to set hostname and/or smtp-hostname
8781 # if the "SERVER" of smtp and "domain" of from don't match.
8782 # The `urlencode' command can be used to encode USER and PASS
8783 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
8784 smtp-auth=login/plain... \e
8787 # Never refuse to start into interactive mode, and more
8789 colour-pager crt= \e
8790 followup-to followup-to-honour=ask-yes \e
8791 history-file=+.\*(uahist history-size=-1 history-gabby \e
8792 mime-counter-evidence=0xE \e
8793 prompt="\e033[31m?\e?[\e$ \e@]\e& \e033[0m" \e
8794 reply-to-honour=ask-yes
8796 # When `p'rinting messages, show only these headers
8797 # (use `P'rint for all headers and `S'how for raw message)
8798 retain date from to cc subject
8800 # Some mailing lists
8801 mlist @xyz-editor.xyz$ @xyzf.xyz$
8802 mlsubscribe ^xfans@xfans.xyz$
8804 # A real life example of a very huge free mail provider
8807 set from="Your Name <youremail@domain>"
8808 # (The plain smtp:// proto is optional)
8809 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
8812 # Here is a pretty large one which does not allow sending mails
8813 # if there is a domain name mismatch on the SMTP protocol level,
8814 # which would bite us if the value of from does not match, e.g.,
8815 # for people who have a sXXXXeforge project and want to speak
8816 # with the mailing list under their project account (in from),
8817 # still sending the message through their normal mail provider
8820 set from="Your Name <youremail@domain>"
8821 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
8822 hostname=yaXXex.com smtp-hostname=
8825 # Create some new commands so that, e.g., `ls /tmp' will..
8836 ghost llS !ls -aFlrS
8839 # We don't support gpg(1) directly yet. But simple --clearsign'd
8840 # message parts can be dealt with as follows:
8843 set pipe-text/plain="@*#++=@\e
8844 < \e"${NAIL_FILENAME_TEMPORARY}\e" awk \e
8845 -v TMPFILE=\e"${NAIL_FILENAME_TEMPORARY}\e" '\e
8847 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
8850 print \e"--- GPG --verify ---\e";\e
8851 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
8852 print \e"--- GPG --verify ---\e";\e
8856 /^-----BEGIN PGP SIGNATURE-----/,\e
8857 /^-----END PGP SIGNATURE-----/ {\e
8867 !printf 'Key IDs to gpg --recv-keys: ';\e
8869 gpg --recv-keys ${keyids};
8875 When storing passwords in
8877 appropriate permissions should be set on this file with
8878 .Ql $ chmod 0600 \*(ur .
8881 is available user credentials can be stored in the central
8883 file instead; e.g., here is a different version of the example account
8884 that sets up SMTP and POP3:
8886 .Bd -literal -offset indent
8889 set from="Your Name <youremail@domain>"
8891 #set agent-shell-lookup="gpg -d .pass.gpg"
8893 set smtp=smtps://smtp.yXXXXx.ru:465 \e
8894 smtp-hostname= hostname=yXXXXx.com
8895 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
8896 ghost xp fi pop3s://pop.yXXXXx.ru
8905 .Bd -literal -offset indent
8906 machine *.yXXXXx.ru login USER password PASS
8911 .Va agent-shell-lookup
8912 is available things could be diversified further by using encrypted
8913 password storage: for this, don't specify
8917 file and instead uncomment the line that defines agent lookup in the
8920 above, then create the encrypted password storage file
8923 .Bd -literal -offset indent
8926 $ eval `gpg-agent --daemon \e
8927 --pinentry-program=/usr/bin/pinentry-curses \e
8928 --max-cache-ttl 99999 --default-cache-ttl 99999`
8932 This configuration should now work just fine (use the
8934 command line option for a(n almost) dry-run):
8937 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
8940 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
8941 .Ss "Signed and encrypted messages with S/MIME"
8943 \*(OP S/MIME provides two central mechanisms:
8944 message signing and message encryption.
8945 A signed message contains some data in addition to the regular text.
8946 The data can be used to verify that the message was sent using a valid
8947 certificate, that the sender's address in the message header matches
8948 that in the certificate, and that the message text has not been altered.
8949 Signing a message does not change its regular text;
8950 it can be read regardless of whether the recipient's software is able to
8954 It is thus usually possible to sign all outgoing messages if so desired.
8955 Encryption, in contrast, makes the message text invisible for all people
8956 except those who have access to the secret decryption key.
8957 To encrypt a message, the specific recipient's public encryption key
8959 It is therefore not possible to send encrypted mail to people unless their
8960 key has been retrieved from either previous communication or public key
8962 A message should always be signed before it is encrypted.
8963 Otherwise, it is still possible that the encrypted message text is
8967 A central concept to S/MIME is that of the certification authority (CA).
8968 A CA is a trusted institution that issues certificates.
8969 For each of these certificates it can be verified that it really
8970 originates from the CA, provided that the CA's own certificate is
8972 A set of CA certificates is usually delivered with OpenSSL and installed
8974 If you trust the source of your OpenSSL software installation,
8975 this offers reasonable security for S/MIME on the Internet.
8977 .Va ssl-no-default-ca
8981 .Va smime-ca-dir . )
8982 In general, a certificate cannot be more secure than the method its CA
8983 certificate has been retrieved with, though.
8984 Thus if you download a CA certificate from the Internet,
8985 you can only trust the messages you verify using that certificate as
8986 much as you trust the download process.
8989 The first thing you need for participating in S/MIME message exchange is
8990 your personal certificate, including a private key.
8991 The certificate contains public information, in particular your name and
8992 your email address(es), and the public key that is used by others to
8993 encrypt messages for you,
8994 and to verify signed messages they supposedly received from you.
8995 The certificate is included in each signed message you send.
8996 The private key must be kept secret.
8997 It is used to decrypt messages that were previously encrypted with your
8998 public key, and to sign messages.
9001 For personal use it is recommended that you get a S/MIME certificate
9002 from one of the major CAs on the Internet using your WWW browser.
9003 Many CAs offer such certificates for free.
9005 .Lk https://www.CAcert.org
9006 which issues client and server certificates to members of their
9007 community for free; their root certificate
9008 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9009 is often not in the default set of trusted CA root certificates, though,
9010 which means you will have to download their root certificate separately
9011 and ensure it is part of our S/MIME certificate validation chain by
9014 or as a vivid member of the
9016 But let's take a step-by-step tour on how to setup S/MIME with
9017 a certificate from CAcert.org despite this situation!
9020 First of all you will have to become a member of the CAcert.org
9021 community, simply by registrating yourself via the web interface.
9022 Once you are, create and verify all email addresses you want to be able
9023 to create signed and encrypted messages for/with using the corresponding
9024 entries of the web interface.
9025 Now ready to create S/MIME certificates, so let's create a new
9026 .Dq client certificate ,
9027 ensure to include all email addresses that should be covered by the
9028 certificate in the following web form, and also to use your name as the
9032 Create a private key and a certificate request on your local computer
9033 (please see the manual pages of the used commands for more in-depth
9034 knowledge on what the used arguments etc. do):
9037 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9040 Afterwards copy-and-paste the content of
9042 into the certificate-request (CSR) field of the web form on the
9043 CAcert.org website (you may need to unfold some
9044 .Dq advanced options
9045 to see the corresponding text field).
9046 This last step will ensure that your private key (which never left your
9047 box) and the certificate belong together (through the public key that
9048 will find its way into the certificate via the certificate-request).
9049 You are now ready and can create your CAcert certified certificate.
9050 Download and store or copy-and-paste it as
9055 In order to use your new S/MIME setup you will have to create
9056 a combined private key/public key (certificate) file:
9059 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9062 This is the file \*(UA will work with.
9063 If you have created your private key with a passphrase then \*(UA will
9064 ask you for it whenever a message is signed or decrypted.
9065 Set the following variables to henceforth use S/MIME (setting
9067 is of interest for verification only):
9069 .Bd -literal -offset indent
9070 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9071 smime-sign-cert=ME@HERE.com.paired \e
9072 smime-sign-message-digest=SHA256 \e
9077 From each signed message you send, the recipient can fetch your
9078 certificate and use it to send encrypted mail back to you.
9079 Accordingly if somebody sends you a signed message, you can do the same,
9082 command to check the validity of the certificate.
9085 Variables of interest for S/MIME signing:
9089 .Va smime-crl-file ,
9090 .Va smime-no-default-ca ,
9092 .Va smime-sign-cert ,
9093 .Va smime-sign-include-certs
9095 .Va smime-sign-message-digest .
9098 After it has been verified save the certificate via
9100 and tell \*(UA that it should use it for encryption for further
9101 communication with that somebody:
9103 .Bd -literal -offset indent
9105 set smime-encrypt-USER@HOST=FILENAME \e
9106 smime-cipher-USER@HOST=AES256
9110 Additional variables of interest for S/MIME en- and decryption:
9113 .Va smime-encrypt-USER@HOST .
9116 You should carefully consider if you prefer to store encrypted messages
9118 If you do, anybody who has access to your mail folders can read them,
9119 but if you do not, you might be unable to read them yourself later if
9120 you happen to lose your private key.
9123 command saves messages in decrypted form, while the
9127 commands leave them encrypted.
9130 Note that neither S/MIME signing nor encryption applies to message
9131 subjects or other header fields yet.
9132 Thus they may not contain sensitive information for encrypted messages,
9133 and cannot be trusted even if the message content has been verified.
9134 When sending signed messages,
9135 it is recommended to repeat any important header information in the
9139 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9140 .Ss "Using CRLs with S/MIME or SSL/TLS"
9142 \*(OP Certification authorities (CAs) issue certificate revocation
9143 lists (CRLs) on a regular basis.
9144 These lists contain the serial numbers of certificates that have been
9145 declared invalid after they have been issued.
9146 Such usually happens because the private key for the certificate has
9148 because the owner of the certificate has left the organization that is
9149 mentioned in the certificate, etc.
9150 To seriously use S/MIME or SSL/TLS verification,
9151 an up-to-date CRL is required for each trusted CA.
9152 There is otherwise no method to distinguish between valid and
9153 invalidated certificates.
9154 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9155 the Internet, so you have to retrieve them by some external mechanism.
9158 \*(UA accepts CRLs in PEM format only;
9159 CRLs in DER format must be converted, like, e.\|g.:
9162 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9165 To tell \*(UA about the CRLs, a directory that contains all CRL files
9166 (and no other files) must be created.
9171 variables, respectively, must then be set to point to that directory.
9172 After that, \*(UA requires a CRL to be present for each CA that is used
9173 to verify a certificate.
9176 .\" .Ss "Handling spam" {{{
9179 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9180 identification of, and, in general, dealing with spam messages.
9181 A precondition of most commands in order to function is that the
9183 variable is set to one of the supported interfaces.
9184 Once messages have been identified as spam their (volatile)
9186 state can be prompted: the
9190 message specifications will address respective messages and their
9192 entries will be used when displaying the
9194 in the header display.
9199 rates the given messages and sets their
9202 If the spam interface offers spam scores those can also be displayed in
9203 the header display by including the
9213 will interact with the Bayesian filter of the chosen interface and learn
9214 the given messages as
9218 respectively; the last command can be used to cause
9220 of messages; it adheres to their current
9222 state and thus reverts previous teachings.
9227 will simply set and clear, respectively, the mentioned volatile
9229 message flag, without any interface interaction.
9236 .Va spam-interface Ns s
9240 require a running instance of the
9242 server in order to function, started with the option
9244 shall Bayesian filter learning be possible.
9246 only works via a local path-based
9248 socket, but otherwise the following will be equivalently fine:
9250 .Bd -literal -offset indent
9251 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9252 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9253 --daemonize [--local] [--allow-tell]
9257 Thereafter \*(UA can make use of these interfaces:
9259 .Bd -literal -offset indent
9260 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9261 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9263 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9264 -Sspamc-command=/usr/local/bin/spamc \e
9265 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9267 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9268 -Sspamc-command=/usr/local/bin/spamc \e
9269 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9273 Using the generic filter approach allows usage of programs like
9277 Here is an example for the former, requiring it to be accessible via
9280 .Bd -literal -offset indent
9281 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
9282 -Sspamfilter-ham="bogofilter -n" \e
9283 -Sspamfilter-noham="bogofilter -N" \e
9284 -Sspamfilter-nospam="bogofilter -S" \e
9285 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9286 -Sspamfilter-spam="bogofilter -s" \e
9287 -Sspamfilter-rate-scanscore="1;^(.+)$"
9291 Because messages must exist on local storage in order to be scored (or
9292 used for Bayesian filter training), it is possibly a good idea to
9293 perform the local spam check last:
9295 .Bd -literal -offset indent
9296 define spamdelhook {
9298 spamset (header x-dcc-brand-metrics "bulk")
9299 # Server-side spamassassin(1)
9300 spamset (header x-spam-flag "YES")
9301 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9307 set folder-hook-FOLDER=spamdelhook
9311 See also the documentation for the variables
9312 .Va spam-interface , spam-maxsize ,
9313 .Va spamc-command , spamc-arguments , spamc-user ,
9314 .Va spamd-socket , spamd-user ,
9315 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9318 .Va spamfilter-rate-scanscore .
9326 .\" .Ss "\*(UA shortly hangs on startup" {{{
9327 .Ss "\*(UA shortly hangs on startup"
9329 This can have two reasons, one is the necessity to wait for a file lock
9330 and can't be helped, the other being that \*(UA calls the function
9332 in order to query the nodename of the box (sometimes the real one is
9333 needed instead of the one represented by the internal variable
9335 You may have varying success by ensuring that the real hostname and
9339 or, more generally, that the name service is properly setup \(en
9342 return what you'd expect?
9343 Does this local hostname has a domain suffix?
9344 RFC 6762 standardized the link-local top-level domain
9348 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9349 .Ss "I can't login to Google mail a.k.a. GMail"
9351 Since 2014 some free service providers classify programs as
9353 unless they use a special authentification method (OAuth 2.0) which
9354 wasn't standardized for non-HTTP protocol authentication token query
9355 until August 2015 (RFC 7628).
9358 Different to Kerberos / GSSAPI, which is developed since the mid of the
9359 1980s, where a user can easily create a local authentication ticket for
9360 her- and himself with the locally installed
9362 program, that protocol has no such local part but instead requires
9363 a world-wide-web query to create or fetch a token; since there is no
9364 local cache this query has to be performed whenever \*(UA is invoked
9365 from the command line (in interactive sessions situation may differ).
9368 \*(UA doesn't support OAuth.
9369 Because of this it is necessary to declare \*(UA a
9371 (on the providers account web page) in order to read and send mail.
9372 However, it also seems possible to take the following steps instead:
9377 give the provider the number of a mobile phone,
9380 .Dq 2-Step Verification ,
9382 create an application specific password (16 characters), and
9384 use that special password instead of your real Google account password in
9385 S-nail (for more on that see the section
9386 .Sx "On URL syntax and credential lookup" ) .
9392 .\" .Sh "SEE ALSO" {{{
9410 .Xr spamassassin 1 ,
9435 M. Douglas McIlroy writes in his article
9436 .Dq A Research UNIX Reader: Annotated Excerpts \
9437 from the Programmer's Manual, 1971-1986
9440 command already appeared in First Edition
9444 .Bd -ragged -offset indent
9445 Electronic mail was there from the start.
9446 Never satisfied with its exact behavior, everybody touched it at one
9447 time or another: to assure the safety of simultaneous access, to improve
9448 privacy, to survive crashes, to exploit uucp, to screen out foreign
9449 freeloaders, or whatever.
9450 Not until v7 did the interface change (Thompson).
9451 Later, as mail became global in its reach, Dave Presotto took charge and
9452 brought order to communications with a grab-bag of external networks
9458 Mail was written in 1978 by Kurt Shoens and developed as part of the
9461 distribution until 1995.
9462 Mail has then seen further development in open source
9464 variants, noticeably by Christos Zoulas in
9466 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9467 Ritter in the years 2000 until 2008.
9468 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9469 This man page is derived from
9470 .Dq The Mail Reference Manual
9471 that was originally written by Kurt Shoens.
9478 .An "Christos Zoulas" ,
9479 .An "Gunnar Ritter" ,
9480 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9482 .Mt s-mailx@sdaoden.eu ) .
9488 The character set conversion uses and relies upon the
9491 Its functionality differs widely between the various system environments
9495 Limitations with IMAP mailboxes are:
9496 It is not possible to edit messages, but it is possible to append them.
9497 Thus to edit a message, create a local copy of it, edit it, append it,
9498 and delete the original.
9499 The line count for the header display is only appropriate if the entire
9500 message has been downloaded from the server.
9501 The marking of messages as `new' is performed by the IMAP server;
9506 will not cause it to be reset, and if the
9508 variable is unset, messages that arrived during a session will not be
9509 in state `new' anymore when the folder is opened again.
9510 Also if commands queued in disconnected mode are committed,
9511 the IMAP server will delete the `new' flag for all messages in the
9513 and new messages will appear as unread when it is selected for viewing
9515 The `flagged', `answered', and `draft' attributes are usually permanent,
9516 but some IMAP servers are known to drop them without notification.
9517 Message numbers may change with IMAP every time before the prompt is
9518 printed if \*(UA is notified by the server that messages have been
9519 deleted by some other client or process.
9520 In this case, `Expunged n messages' is printed, and message numbers may
9524 Limitations with POP3 mailboxes are:
9525 It is not possible to edit messages, they can only be copied and deleted.
9526 The line count for the header display is only appropriate if the entire
9527 message has been downloaded from the server.
9528 The status field of a message is maintained by the server between
9529 connections; some servers do not update it at all, and with a server
9532 command will not cause the message status to be reset.
9537 variable have no effect.
9538 It is not possible to rename or to remove POP3 mailboxes.
9545 is typed while an IMAP or POP3 operation is in progress, \*(UA will wait
9546 until the operation can be safely aborted, and will then return to the
9547 command loop and print the prompt again.
9550 is typed while \*(UA is waiting for the operation to complete, the
9551 operation itself will be cancelled.
9552 In this case, data that has not been fetched yet will have to be fetched
9553 before the next command can be performed.
9554 If the cancelled operation was using an SSL/TLS encrypted channel,
9555 an error in the SSL transport will very likely result and render the
9556 connection unusable.
9559 As \*(UA is a mail user agent, it provides only basic SMTP services.
9560 If it fails to contact its upstream SMTP server, it will not make
9561 further attempts to transfer the message at a later time,
9562 and it does not leave other information about this condition than an
9563 error message on the terminal and an entry in
9565 This is usually not a problem if the SMTP server is located in the same
9566 local network as the computer on which \*(UA is run.
9567 However, care should be taken when using a remote server of an ISP;
9568 it might be better to set up a local SMTP server then which just acts as
9572 \*(UA immediately contacts the SMTP server (or
9574 ) even when operating in
9577 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9578 servers usually provide much more elaborated delay handling than \*(UA
9579 could perform as a client.
9580 Thus the recommended setup for sending mail in
9582 mode is to configure a local SMTP server such that it sends outgoing
9583 mail as soon as an external network connection is available again,
9584 i.e., to advise it to do that from a network startup script.
9590 With IMAP, at least if the IMAP cache is used, if multiple
9594 cycles happen without an intervening change of the active mailbox then
9595 \*(UA will at some time loose the ability to keep the local state
9596 up-to-date, meaning that, e.g., messages show up with false numbers, and
9597 including the possibility that messages are accessed via numbers that
9598 are no(t longer) valid, resulting in program crashes.
9599 The solution is to change the active mailbox before that happens :).
9602 from the distribution or the repository.
9604 After deleting some message of a POP3 mailbox the header summary falsely
9605 claims that there are no messages to display, you need to perform
9606 a scroll or dot movement to restore proper state.
9608 In threaded display a power user may encounter crashes very
9609 occasionally (this is may and very).