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 Display 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 Show 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 Display 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 Show \*(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 display only the summaries of the given messages, defaulting to the
897 Messages can be displayed on the user's terminal with the
901 By default the current message
903 is displayed, but like with many 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 type the messages 1 and 5,
915 will type the messages 1 through 5, and
919 will display the last and the next message, respectively.
922 (a more substantial alias of the standard command
924 will display a header summary of the given message specification list
925 instead of their content, e.g., the following will search for subjects:
928 .Dl ? from """@Some subject to search for"""
931 In the default setup all header fields of a message will be displayed,
932 but this can be changed: either by blacklisting a list of fields via
934 or by whitelisting only a given list with the
937 .Ql Ic \:retain Ns \0date from to cc subject .
938 In order to display all header fields of a message regardless of
939 currently active ignore or retain lists, use the command
943 controls wether and when \*(UA will use the configured
945 for display instead of directly writing to the user terminal
946 (generally speaking).
947 Note that historically the global
949 not only adjusts the list of displayed headers, but also sets
953 Dependent upon the configuration a
954 .Sx "Command line editor"
955 aims at making user experience with the many
958 When reading the system mailbox or when
962 specified a mailbox explicitly prefixed with the special
964 modifier (propagating the mailbox to a primary one) then messages which
965 have been read will be moved to a secondary mailbox, the user's
967 file, automatically when the mailbox is left, either by changing the
968 active mailbox or by quitting \*(UA (also see
969 .Sx "Message states" )
970 \(en this automatic moving from a system or primary to the secondary
971 mailbox is not performed when the variable
976 After examining a message the user can also
980 to the sender and all recipients or
982 exclusively to the sender(s).
987 Note that when replying to or forwarding a message recipient addresses
988 will be stripped from comments and names unless the option
991 Deletion causes \*(UA to forget about the message;
992 This is not irreversible, though, one can
994 the message by giving its number,
995 or the \*(UA session can be ended by giving the
1000 To end a mail processing session one may either issue
1002 to cause a full program exit, which possibly includes
1003 automatic moving of read messages to
1005 as well as updating the \*(OPal command line editor history file,
1008 instead in order to prevent any of these actions.
1011 .\" .Ss "HTML mail and MIME attachments" {{{
1012 .Ss "HTML mail and MIME attachments"
1014 Messages which are HTML-only get more and more common and of course many
1015 messages come bundled with a bouquet of MIME attachments.
1016 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
1017 with HTML messages (see
1018 .Sx "The mime.types files" ) ,
1019 it normally can't deal with any of these itself, but instead programs
1020 need to become registered to deal with specific MIME types or file
1022 These programs may either prepare plain text versions of their input
1023 in order to enable \*(UA to display the content on the terminal,
1024 or display the content themselves, for example in a graphical window.
1027 To install an external handler program for a specific MIME type set an
1029 .Va pipe-TYPE/SUBTYPE
1030 variable; to instead define a handler for a specific file extension set
1033 variable \(en these handlers take precedence.
1034 \*(OPally \*(UA supports mail user agent configuration as defined in
1035 RFC 1524; this mechanism, documented in the section
1036 .Sx "The Mailcap files" ,
1037 will be queried for display or quote handlers if none of the former two
1038 .\" TODO v15-compat "will be" -> "is"
1039 did; it will be the sole source for handlers of other purpose.
1040 A last source for handlers may be the MIME type definition itself, if
1041 the \*(UA specific type-marker extension was used when defining the type
1044 (Many of the builtin MIME types do so by default.)
1048 .Va mime-counter-evidence
1049 can be set to improve dealing with faulty MIME part declarations as are
1050 often seen in real-life messages.
1051 E.g., to display a HTML message inline (that is, converted to a more
1052 fancy plain text representation than the builtin converter is capable to
1053 produce) with either of the text-mode browsers
1057 teach \*(UA about MathML documents and make it display them as plain
1058 text, and to open PDF attachments in an external PDF viewer,
1059 asynchronously and with some other magic attached:
1061 .Bd -literal -offset indent
1062 if $features !@ HTML-FILTER
1063 #set pipe-text/html="elinks -force-html -dump 1"
1064 set pipe-text/html="lynx -stdin -dump -force_html"
1065 # Display HTML as plain text instead
1066 #set pipe-text/html=@
1068 mimetype '@ application/mathml+xml mathml'
1069 set pipe-application/pdf="@&=@ \e
1070 trap \e"rm -f \e\e\e"${NAIL_FILENAME_TEMPORARY}\e\e\e"\e" EXIT;\e
1071 trap \e"trap \e\e\e"\e\e\e" INT QUIT TERM; exit 1\e" \e INT QUIT TERM;\e
1072 xpdf \e"${NAIL_FILENAME_TEMPORARY}\e""
1076 Note: special care must be taken when using such commands as mail
1077 viruses may be distributed by this method: if messages of type
1078 .Ql application/x-sh
1079 or files with the extension
1081 were blindly filtered through the shell, for example, a message sender
1082 could easily execute arbitrary code on the system \*(UA is running on.
1083 For more on MIME, also in respect to sending of messages, see the
1085 .Sx "The mime.types files" ,
1086 .Sx "The Mailcap files"
1091 .\" .Ss "Mailing lists" {{{
1094 \*(UA offers some support to ease handling of mailing lists.
1097 promotes all given arguments to known mailing lists, and
1099 sets their subscription attribute, creating them first as necessary.
1104 automatically, but only resets the subscription attribute.)
1105 Using the commands without arguments will show (a subset of) all
1106 currently defined mailing lists.
1111 can be used to mark out messages with configured list addresses
1112 in the header display.
1115 \*(OPally mailing lists may also be specified as (extended) regular
1116 expressions, which allows matching of many addresses with a single
1118 However, all fully qualified list addresses are matched via a fast
1119 dictionary, whereas expressions are placed in (a) list(s) which is
1120 (are) matched sequentially.
1122 .Bd -literal -offset indent
1123 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1124 mlist a1@b1.c1 a2@b2.c2 .*@lists.c3$
1125 mlsubscribe a4@b4.c4 exact@lists.c3
1130 .Va followup-to-honour
1132 .Ql Mail-\:Followup-\:To:
1133 header is honoured when the message is being replied to (via
1139 controls wether this header is created when sending mails; it will be
1140 created automatically for a couple of reasons, too, like when the
1142 .Dq mailing list specific
1147 is used to respond to a message with its
1148 .Ql Mail-Followup-To:
1152 A difference in between the handling of known and subscribed lists is
1153 that the address of the sender is usually not part of a generated
1154 .Ql Mail-Followup-To:
1155 when addressing the latter, whereas it is for the former kind of lists.
1156 Usually because there are exceptions: say, if multiple lists are
1157 addressed and not all of them are subscribed lists.
1159 For convenience \*(UA will, temporarily, automatically add a list
1160 address that is presented in the
1162 header of a message that is being responded to to the list of known
1164 Shall that header have existed \*(UA will instead, dependend on the
1166 .Va reply-to-honour ,
1169 for this purpose in order to accept a list administrators' wish that
1170 is supposed to have been manifested like that (but only if it provides
1171 a single address which resides on the same domain as what is stated in
1175 .\" .Ss "Resource files" {{{
1176 .Ss "Resource files"
1178 Upon startup \*(UA reads in several resource files:
1180 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1183 System wide initialization file.
1184 Reading of this file can be suppressed, either by using the
1186 command line option, or by setting the environment variable
1187 .Ev NAIL_NO_SYSTEM_RC .
1191 File giving initial commands.
1192 A different file can be chosen by setting the environment variable
1195 .It Va NAIL_EXTRA_RC
1196 Can be used to define an optional startup file to be read after
1198 This variable is only honoured in certain circumstances (see its
1199 documentation for more).
1203 The content of these files is interpreted as follows:
1206 .Bl -bullet -compact
1208 A lines' leading whitespace is removed.
1210 Empty lines are ignored.
1212 Any other line is interpreted as a command.
1213 It may be spread over multiple input lines if the newline character is
1215 by placing a backslash character
1217 as the last character of the line; whereas any leading whitespace of
1218 follow lines is ignored, trailing whitespace before a escaped newline
1219 remains in the input.
1221 If the line (content) starts with the number sign
1223 then it is a comment-command \(en a real command! \(en and also ignored.
1224 This command is the only form of comment that is understood.
1230 .Bd -literal -offset indent
1231 # This line is a comment command. And y\e
1232 es, it is really continued here.
1239 .\" .Ss "Character sets" {{{
1240 .Ss "Character sets"
1242 \*(OP \*(UA detects the character set of the terminal by using
1243 mechanisms that are controlled by the
1248 should give an overview); the \*(UA internal variable
1250 will be set to the detected terminal character set accordingly
1251 and will thus show up in the output of the commands
1257 However, a user supplied
1259 value is not overwritten by this detection mechanism: this
1261 must be used if the detection doesn't work properly,
1262 and it may be used to adjust the name of the locale character set.
1263 E.g., on BSD systems one may use a locale with the character set
1264 ISO8859-1, which is not a valid name for this character set; to be on
1265 the safe side, one may set
1267 to the correct name, which is ISO-8859-1.
1270 Note that changing the value doesn't mean much beside that,
1271 since several aspects of the real character set are implied by the
1272 locale environment of the system,
1273 and that stays unaffected by the content of an overwritten
1276 (This is mostly an issue when interactively using \*(UA, though.
1277 It is actually possible to send mail in a completely
1279 locale environment, an option that \*(UA's test-suite uses excessively.)
1282 If no character set conversion capabilities have been compiled into
1285 doesn't include the term
1289 will be the only supported character set,
1290 it is simply assumed that it can be used to exchange 8-bit messages,
1291 and the rest of this section does not apply;
1292 it may however still be necessary to explicitly set it if automatic
1293 detection fails, since in that case it defaults to the mentioned
1294 .\" (Keep in SYNC: ./nail.1:"Character sets", ./nail.h:CHARSET_*!)
1298 When reading messages, their text is converted into
1300 as necessary in order to display them on the users terminal.
1301 Unprintable characters and invalid byte sequences are detected
1302 and replaced by proper substitution characters (unless the variable
1304 was set once \*(UA was started).
1306 .Va charset-unknown-8bit
1307 to deal with another hairy aspect of message interpretation.
1310 When sending messages all their parts and attachments are classified.
1311 Whereas no character set conversion is performed on those parts which
1312 appear to be binary data,
1313 the character set being used must be declared within the MIME header of
1314 an outgoing text part if it contains characters that do not conform to
1315 the set of characters that are allowed by the email standards.
1316 Permissible values for character sets can be declared using the
1320 which defines a catch-all last-resort fallback character set that is
1321 implicitly appended to the list of character-sets in
1325 When replying to a message and the variable
1326 .Va reply-in-same-charset
1327 is set then the character set of the message being replied to is tried
1329 And it is also possible to make \*(UA work even more closely related to
1330 the current locale setting automatically by using the variable
1331 .Va sendcharsets-else-ttycharset ,
1332 please see there for more information.
1335 All the specified character sets are tried in order unless the
1336 conversion of the part or attachment succeeds.
1337 If none of the tried (8-bit) character sets is capable to represent the
1338 content of the part or attachment,
1339 then the message will not be sent and its text will optionally be
1343 In general, if the message
1344 .Dq Cannot convert from a to b
1345 appears, either some characters are not appropriate for the currently
1346 selected (terminal) character set,
1347 or the needed conversion is not supported by the system.
1348 In the first case, it is necessary to set an appropriate
1350 locale and/or the variable
1354 The best results are usually achieved when \*(UA is run in a UTF-8
1355 locale on a UTF-8 capable terminal, in which case the full Unicode
1356 spectrum of characters is available.
1357 In this setup characters from various countries can be displayed,
1358 while it is still possible to use more simple character sets for sending
1359 to retain maximum compatibility with older mail clients.
1362 On the other hand the POSIX standard defines a locale-independent 7-bit
1363 .Dq portable character set
1364 that should be used when overall portability is an issue, the even more
1365 restricted subset named
1366 .Dq portable filename character set
1367 consisting of A-Z, a-z, 0-9, period
1376 .\" .Ss "Message states" {{{
1377 .Ss "Message states"
1379 \*(UA differentiates in between several different message states;
1380 the current state will be reflected in header summary displays if
1382 is configured to do so (via the internal variable
1384 and messages can also be selected and be acted upon depending on their
1386 .Sx "Specifying messages" ) .
1387 When operating on the system mailbox or in primary mailboxes opened with
1392 special actions, like the automatic moving of messages to the secondary
1394 mailbox may be applied when the mailbox is left (also implicitly via
1395 a successful exit of \*(UA, but not if the special command
1397 is used) \(en however, because this may be irritating to users which
1400 mail-user-agents, the default global
1406 variables in order to suppress this behaviour.
1408 .Bl -tag -width ".It Ql _reserved"
1410 Message has neither been viewed nor moved to any other state.
1411 Such messages are retained even in the system mailbox.
1414 Message has neither been viewed nor moved to any other state, but the
1415 message was present already when the mailbox has been opened last:
1416 Such messages are retained even in the system mailbox.
1419 The message has been processed by one of the following commands:
1439 commands may also cause the next message to be marked as read, depending
1445 command is used, messages that are in the system mailbox or in mailboxes
1446 which were opened with the special
1450 state when the mailbox is left will be saved in
1457 The message has been processed by one of the following commands:
1463 can be used to access such messages.
1466 The message has been processed by a
1468 command and it will be retained in its current location.
1471 The message has been processed by one of the following commands:
1477 command is used, messages that are in the system mailbox or in mailboxes
1478 which were opened with the special
1482 state when the mailbox is left will be deleted; they will be saved in
1490 .\" .Ss "Specifying messages" {{{
1491 .Ss "Specifying messages"
1498 can be given a list of message numbers as arguments to apply to a number
1499 of messages at once.
1502 deletes messages 1 and 2,
1505 will delete the messages 1 through 5.
1506 In sorted or threaded mode (see the
1510 will delete the messages that are located between (and including)
1511 messages 1 through 5 in the sorted/threaded order, as shown in the
1514 Multiple colon modifiers can be joined into one, e.g.,
1516 The following special message names exist:
1518 .Bl -tag -width ".It Ar _n_u"
1524 All old messages (any not in state
1549 All answered messages
1554 All messages marked as draft.
1556 \*(OP All messages classified as spam.
1558 \*(OP All messages with unsure spam classification.
1560 The current message, the so-called
1563 The message that was previously the current message.
1565 The parent message of the current message,
1566 that is the message with the Message-ID given in the
1568 field or the last entry of the
1570 field of the current message.
1572 The next previous undeleted message,
1573 or the next previous deleted message for the
1576 In sorted/threaded mode,
1577 the next previous such message in the sorted/threaded order.
1579 The next undeleted message,
1580 or the next deleted message for the
1583 In sorted/threaded mode,
1584 the next such message in the sorted/threaded order.
1586 The first undeleted message,
1587 or the first deleted message for the
1590 In sorted/threaded mode,
1591 the first such message in the sorted/threaded order.
1594 In sorted/threaded mode,
1595 the last message in the sorted/threaded order.
1599 selects the message addressed with
1603 is any other message specification,
1604 and all messages from the thread that begins at it.
1605 Otherwise it is identical to
1610 the thread beginning with the current message is selected.
1615 All messages that were included in the message list for the previous
1618 .It Ar / Ns Ar string
1619 All messages that contain
1621 in the subject field (case ignored).
1628 the string from the previous specification of that type is used again.
1630 .It Xo Op Ar @ Ns Ar name-list Ns
1633 All messages that contain the given case-insensitive search
1635 ession; if the \*(OPal regular expression (see
1637 support is available
1639 will be interpreted as (an extended) one if any of the
1641 (extended) regular expression characters is seen.
1643 .Ar @ Ns Ar name-list
1644 part is missing, the search is restricted to the subject field body,
1647 specifies a comma-separated list of header fields to search, as in
1649 .Dl '@to,from,cc@Someone i ought to know'
1651 In order to search for a string that includes a
1653 (commercial at) character the
1655 is effectively non-optional, but may be given as the empty string.
1656 Some special header fields may be abbreviated:
1670 respectively and case-insensitively.
1675 can be used to search in (all of) the header(s) of the message, and the
1684 can be used to perform full text searches \(en whereas the former
1685 searches only the body, the latter also searches the message header.
1687 This message specification performs full text comparison, but even with
1688 regular expression support it is almost impossible to write a search
1689 expression that savely matches only a specific address domain.
1690 To request that the content of the header is treated as a list of
1691 addresses, and to strip those down to the plain email address which the
1692 search expression is to be matched against, prefix the header name
1693 (abbreviation) with a tilde
1696 .Dl @~f@@a\e.safe\e.domain\e.match$
1700 .Dq any substring matches
1703 header, which will match addresses (too) even if
1705 is set (and POSIX says
1706 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1709 variable is set, only the local part of the address is evaluated
1710 for the comparison, not ignoring case, and the setting of
1712 is completely ignored.
1713 For finer control and match boundaries use the
1715 search expression; the \*(OPal IMAP-style
1717 expression can also be used if substring matches are desired.
1721 \*(OP IMAP-style SEARCH expressions may also be used.
1722 This addressing mode is available with all types of folders;
1723 \*(UA will perform the search locally as necessary.
1724 Strings must be enclosed by double quotes
1726 in their entirety if they contain white space or parentheses;
1727 within the quotes, only backslash
1729 is recognized as an escape character.
1730 All string searches are case-insensitive.
1731 When the description indicates that the
1733 representation of an address field is used,
1734 this means that the search string is checked against both a list
1737 .Bd -literal -offset indent
1738 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1743 and the addresses without real names from the respective header field.
1744 These search expressions can be nested using parentheses, see below for
1748 .Bl -tag -compact -width ".It Ar _n_u"
1749 .It Ar ( criterion )
1750 All messages that satisfy the given
1752 .It Ar ( criterion1 criterion2 ... criterionN )
1753 All messages that satisfy all of the given criteria.
1755 .It Ar ( or criterion1 criterion2 )
1756 All messages that satisfy either
1761 To connect more than two criteria using
1763 specifications have to be nested using additional parentheses,
1765 .Ql (or a (or b c)) ,
1769 .Ql ((a or b) and c) .
1772 operation of independent criteria on the lowest nesting level,
1773 it is possible to achieve similar effects by using three separate
1777 .It Ar ( not criterion )
1778 All messages that do not satisfy
1780 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1781 All messages that contain
1783 in the envelope representation of the
1786 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1787 All messages that contain
1789 in the envelope representation of the
1792 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1793 All messages that contain
1795 in the envelope representation of the
1798 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1799 All messages that contain
1804 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1805 All messages that contain
1807 in the envelope representation of the
1810 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1811 All messages that contain
1816 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1817 All messages that contain
1820 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1821 All messages that contain
1823 in their header or body.
1824 .It Ar ( larger size )
1825 All messages that are larger than
1828 .It Ar ( smaller size )
1829 All messages that are smaller than
1833 .It Ar ( before date )
1834 All messages that were received before
1836 which must be in the form
1840 denotes the day of the month as one or two digits,
1842 is the name of the month \(en one of
1843 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1846 is the year as four digits, e.g.,
1850 All messages that were received on the specified date.
1851 .It Ar ( since date )
1852 All messages that were received since the specified date.
1853 .It Ar ( sentbefore date )
1854 All messages that were sent on the specified date.
1855 .It Ar ( senton date )
1856 All messages that were sent on the specified date.
1857 .It Ar ( sentsince date )
1858 All messages that were sent since the specified date.
1860 The same criterion as for the previous search.
1861 This specification cannot be used as part of another criterion.
1862 If the previous command line contained more than one independent
1863 criterion then the last of those criteria is used.
1867 .\" .Ss "On URL syntax and credential lookup" {{{
1868 .Ss "On URL syntax and credential lookup"
1870 \*(IN For accessing protocol-specific resources usage of Uniform
1871 Resource Locators (URL, RFC 1738) has become omnipresent.
1872 \*(UA expects and understands URLs in the following form;
1875 denote optional parts, optional either because there also exist other
1876 ways to define the information in question or because support of the
1877 part is protocol-specific (e.g.,
1879 is used by the IMAP protocol but not by POP3);
1884 are specified they must be given in URL percent encoded form (RFC 3986;
1892 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1895 Note that these \*(UA URLs most often don't conform to any real
1896 standard, but instead represent a normalized variant of RFC 1738 \(en
1897 they are not used in data exchange but only ment as a compact,
1898 easy-to-use way of defining and representing information in
1899 a well-known notation.
1902 Many internal variables of \*(UA exist in multiple versions, called
1903 variable chains for the rest of this document: the plain
1908 .Ql variable-USER@HOST .
1915 had been specified in the respective URL, otherwise it refers to the plain
1921 that had been found when doing the user chain lookup as is described
1924 will never be in URL percent encoded form, wether it came from an URL or
1925 not; i.e., values of
1926 .Sx "INTERNAL VARIABLES"
1927 must not be URL percent encoded.
1930 For example, wether an hypothetical URL
1931 .Ql smtp://hey%3Ayou@our.house
1932 had been given that includes a user, or wether the URL was
1933 .Ql smtp://our.house
1934 and the user had been found differently, to lookup the variable chain
1935 .Va smtp-use-starttls
1936 \*(UA first looks for wether
1937 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1938 is defined, then wether
1939 .Ql smtp-\:use-\:starttls-\:our.house
1940 exists before finally ending up looking at the plain variable itself.
1943 \*(UA obeys the following logic scheme when dealing with the
1944 necessary credential informations of an account:
1950 has been given in the URL the variables
1954 are looked up; if no such variable(s) can be found then \*(UA will,
1955 when enforced by the \*(OPal variables
1956 .Va netrc-lookup-HOST
1963 specific entry which provides a
1965 name: this lookup will only succeed if unambiguous (one possible matching
1969 If there is still no
1971 then \*(UA will fall back to the user who is supposed to run \*(UA:
1972 either the name that has been given with the
1974 command line option (or, equivalently, but with less precedence, the
1975 environment variable
1980 The identity of this user has been fixated during \*(UA startup and is
1981 known to be a valid user on the current host.
1984 Authentication: unless otherwise noted this will lookup the
1985 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
1986 variable chain, falling back to a protocol-specific default should this
1992 has been given in the URL, then if the
1994 has been found through the \*(OPal
1996 then that may have already provided the password, too.
1997 Otherwise the variable chain
1998 .Va password-USER@HOST , password-HOST , password
1999 is looked up and used if existent.
2001 \*(OP Then if any of the variables of the chain
2002 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
2004 is set the shell command specified therein is run and the output (less
2005 newline characters) will be used as the password.
2006 It is perfectly valid for such an agent to simply not return any data,
2007 in which case the password lookup is continued somewhere else;
2008 Any command failure is treated as a hard error, however.
2010 Afterwards the complete \*(OPal variable chain
2011 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
2015 cache is searched for a password only (multiple user accounts for
2016 a single machine may exist as well as a fallback entry without user
2017 but with a password).
2019 If at that point there is still no password available, but the
2020 (protocols') chosen authentication type requires a password, then in
2021 interactive mode the user will be prompted on the terminal.
2026 S/MIME verification works relative to the values found in the
2030 header field(s), which means that the values of
2031 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
2033 .Va smime-sign-message-digest
2034 will not be looked up using the
2038 chains from above but instead use the corresponding values from the
2039 message that is being worked on.
2040 In unusual cases multiple and different
2044 combinations may therefore be involved \(en on the other hand those
2045 unusual cases become possible.
2046 The usual case is as short as:
2049 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
2050 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
2055 contains complete example configurations.
2058 .\" .Ss "Command line editor" {{{
2059 .Ss "Command line editor"
2061 \*(OP \*(UA can be configured to support a command line editor and
2062 command history lists which are saved in between sessions.
2063 One may link against fully-fledged external libraries
2064 .Pf ( Xr readline 6 ,
2066 ) or use \*(UA's own command line editor NCL (Nail-Command-Line)
2067 instead, which should work in all environments which comply to the
2068 ISO C standard (ISO/IEC 9899:1990/Amendment 1:1995).
2069 When an external library is used, interactive behaviour of \*(UA relies
2070 on that library and may not correspond one-to-one to what is described
2074 Regardless of the actually used command line editor
2076 entries will be created for lines entered in command mode only, and
2077 creation of such an entry can be forcefully suppressed by starting the
2078 line with a space character.
2081 handling is by itself an optional feature and may therefore not be
2083 For more information see the documentation of the variables
2087 .Va history-gabby-persist ,
2090 .Va line-editor-disable .
2091 And there is also the \*(OPal
2093 will can be set to cause overall screen resets when \*(UA releases the
2094 terminal in interactive mode.
2097 The builtin \*(UA command line editor supports the following operations;
2100 stands for the combination of the
2102 key plus the mentioned character, e.g.,
2105 .Dq hold down control key and press the A key :
2108 .Bl -tag -compact -width "Ql _M"
2110 Go to the start of the line.
2112 Move the cursor backward one character.
2114 Forward delete the character under the cursor;
2115 quits \*(UA if used on the empty line unless the
2119 Go to the end of the line.
2121 Move the cursor forward one character.
2124 Cancel current operation, full reset.
2125 If there is an active history search or tabulator expansion then this
2126 command will first reset that, reverting to the former line content;
2127 thus a second reset is needed for a full reset in this case.
2128 In all cases \*(UA will reset a possibly used multibyte character input
2134 backward delete one character.
2138 .Dq horizontal tabulator :
2139 try to expand the word before the cursor.
2141 .Dq tabulator-completion
2142 as is known from the
2144 but really means the usual \*(UA expansion, as documented for
2146 yet it involves shell expansion as a last step, too.)
2151 complete this line of input.
2153 Delete all characters from the cursor to the end of the line.
2157 \*(OP Go to the next history entry.
2162 \*(OP Go to the previous history entry.
2164 \*(OP Complete the current line from (the remaining older) history entries.
2171 Delete the characters from the one preceding the cursor to the preceding
2174 Move the cursor forward one word boundary.
2176 Move the cursor backward one word boundary.
2180 If problems with commands that are based upon rightwise movement are
2181 encountered, adjustments of the option
2182 .Va line-editor-cursor-right
2183 may solve the problem, as documented for it.
2186 If the terminal produces key sequences which are compatible with
2188 then the left and right cursor keys will map to
2192 respectively, the up and down cursor keys will map to
2196 and the Home/End/PgUp/PgDown keys will call the
2198 command with the respective arguments
2204 (i.e., perform scrolling through the header summary list).
2207 .\" .Ss "Coloured message display" {{{
2208 .Ss "Coloured message display"
2210 \*(OP \*(UA can be configured to support coloured message display,
2211 realized by emitting ANSI colour escape sequences.
2212 Colours are only used when the
2214 environment variable is set and either the terminal type can be found in
2216 or its name includes the string
2220 On top of what \*(UA knows about the terminal the boolean variable
2222 defines wether these colour sequences are also generated when the output
2223 of a command needs to go through the
2227 ) \(en this is not enabled by default because different pager programs
2228 need different command line switches or other configuration in order to
2229 support those colour sequences, please see the option for more details.
2232 To forcefully disable all colour support, set
2233 .Va colour-disable .
2236 Colours can be configured through font attributes
2257 Multiple specifications can be joined in a comma separated list, as in
2260 .Dl set colour-msginfo="ft=bold,fg=magenta,bg=cyan"
2263 Variables to be set are
2264 .Va colour-msginfo ,
2265 .Va colour-partinfo ,
2269 .Va colour-uheader ,
2271 .Va colour-user-headers ,
2272 which is a list of headers to be colourized via
2274 instead of the default
2277 .\" }}} (DESCRIPTION)
2280 .\" .Sh COMMANDS {{{
2283 Each command is typed on a line by itself,
2284 and may take arguments following the command word.
2285 The command need not be typed in its entirety \(en
2286 the first command which matches the typed prefix is used.
2287 An \(en alphabetically \(en sorted list of commands can be shown
2294 when given an argument, will show a documentation string for the
2295 command matching the expanded argument, as in
2297 which should be a shorthand of
2299 documentation strings are however \*(OPal.
2302 For commands which take message lists as arguments, the next message
2303 forward that satisfies the command's requirements will be used shall no
2304 explicit message list have been specified.
2305 If there are no messages forward of the current message,
2306 the search proceeds backwards,
2307 and if there are no good messages at all,
2309 .Dq no applicable messages
2310 and aborts the command.
2311 The arguments to commands can be quoted, using the following methods:
2314 .Bl -bullet -compact -offset indent
2316 An argument can be enclosed between paired double-quotes
2321 any white space, shell word expansion, or backslash characters (except
2322 as described next) within the quotes are treated literally as part of
2324 A double-quote will be treated literally within single-quotes and vice
2326 Inside such a quoted string the actually used quote character can be
2327 used nonetheless by escaping it with a backslash
2333 An argument that is not enclosed in quotes, as above, can usually still
2334 contain space characters if those spaces are backslash-escaped, as in
2338 A backslash outside of the enclosing quotes is discarded
2339 and the following character is treated literally as part of the argument.
2342 An unquoted backslash at the end of a command line is discarded and the
2343 next line continues the command.
2347 Filenames, where expected, are subsequently subjected to the following
2348 transformations, in sequence:
2351 .Bl -bullet -compact -offset indent
2353 If the filename begins with an unquoted plus sign, and the
2355 variable is defined,
2356 the plus sign will be replaced by the value of the
2358 variable followed by a slash.
2361 variable is unset or is set to null, the filename will be unchanged.
2364 Shell word expansions are applied to the filename.
2365 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2366 .Sy Compatibility note:
2367 on the long run support for complete shell word expansion will be
2368 replaced by an internally implemented restricted expansion mechanism in
2369 order to circumvent possible security impacts through shell expansion.
2370 Expect that a growing number of program parts only support this
2373 Meta expansions are applied to the filename: leading tilde characters
2375 will be replaced by the expansion of
2377 and any occurrence of
2381 will be replaced by the expansion of the variable, if possible;
2382 \*(UA internal as well as environmental (shell) variables can be
2383 accessed through this mechanism.
2384 In order to include a raw
2386 character precede it with a backslash
2388 to include a backslash double it.
2389 If more than a single pathname results from this expansion and the
2390 command is expecting one file, an error results.
2392 Note that in interactive display context, in order to allow simple
2393 value acceptance (typing
2395 backslash quoting is performed automatically as necessary, e.g., a file
2396 .Ql diet\e is \ecurd.txt
2397 will be displayed as
2398 .Ql diet\e\e is \e\ecurd.txt .
2402 The following commands are available:
2404 .Bl -tag -width ".Ic _ccount"
2411 ) command which follows.
2415 The comment-command causes the entire line to be ignored.
2417 this really is a normal command which' purpose is to discard its
2420 indicating special character, which means that, e.g., trailing comments
2421 on a line are not possible.
2425 Goes to the next message in sequence and types it
2431 Display the preceding message, or the n'th previous message if given
2432 a numeric argument n.
2436 Show the current message number (the
2441 Show a brief summary of commands.
2442 \*(OP Given an argument a synopsis for the command in question is
2443 shown instead; commands can be abbreviated in general and this command
2444 can be used to see the full expansion of an abbreviation including the
2445 synopsis, try, e.g.,
2450 and see how the output changes.
2460 Interprets the remainder of the word as a macro name and passes it
2465 is a shorter synonym for
2466 .Ql call Ar mymacro .
2470 (ac) Creates, selects or lists (an) account(s).
2471 An account is a group of commands and variable settings which together
2472 usually arrange the environment for the purpose of creating a system login.
2473 Without any argument a listing of all defined accounts and their content
2475 A specific account can be activated by giving solely its name, resulting
2476 in the system mailbox or inbox of that account to be activated as via an
2477 explicit use of the command
2479 The two argument form is identical to defining a macro as via
2482 .Bd -literal -offset indent
2484 set folder=imaps://mylogin@imap.myisp.example
2486 set from="myname@myisp.example (My Name)"
2487 set smtp=smtp://mylogin@smtp.myisp.example
2491 creates an account named
2493 which can later be selected by specifying
2497 (case-insensitive) always exists.
2499 can be used to localize account settings \(en different to normal macros
2500 the settings will be reverted once the account is switched off.
2501 Accounts can be deleted via
2506 (a) With no arguments, shows all currently-defined aliases.
2507 With one argument, shows that alias.
2508 With more than one argument,
2509 creates a new alias or appends to an existing one.
2511 can be used to delete aliases.
2515 (alt) Manage a list of alternate addresses / names of the active user,
2516 members of which will be removed from recipient lists when replying to
2519 variable is not set).
2520 If arguments are given the set of alternate names is replaced by them,
2521 without arguments the current set is displayed.
2525 Takes a message list and marks each message as having been answered.
2526 This mark has no technical meaning in the mail system;
2527 it just causes messages to be marked in the header summary,
2528 and makes them specially addressable.
2532 \*(OP\*(OB Only applicable to cached IMAP mailboxes;
2533 takes a message list and reads the specified messages into the IMAP
2538 Calls a macro that has been created via
2543 (ch) Change the working directory to
2545 or the given argument.
2551 \*(OP Only applicable to S/MIME signed messages.
2552 Takes a message list and a file name and saves the certificates
2553 contained within the message signatures to the named file in both
2554 human-readable and PEM format.
2555 The certificates can later be used to send encrypted messages to the
2556 respective message senders by setting
2557 .Va smime-encrypt-USER@HOST
2562 (ch) Change the working directory to
2564 or the given argument.
2570 Only applicable to threaded mode.
2571 Takes a message list and makes all replies to these messages invisible
2572 in header summaries, unless they are in state
2577 \*(OP\*(OB If operating in disconnected mode on an IMAP mailbox,
2578 switch to online mode and connect to the mail server while retaining
2580 See the description of the
2582 variable for more information.
2586 (C) Copy messages to files whose names are derived from the author of
2587 the respective message and don't mark them as being saved;
2588 otherwise identical to
2593 (c) Copy messages to the named file and don't mark them as being saved;
2594 otherwise identical to
2599 Show the name of the current working directory.
2603 \*(OP For unencrypted messages this command is identical to
2605 Encrypted messages are first decrypted, if possible, and then copied.
2609 \*(OP For unencrypted messages this command is identical to
2611 Encrypted messages are first decrypted, if possible, and then copied.
2615 Without arguments the current list of macros, including their content,
2616 is shown, otherwise a macro is defined.
2617 A macro definition is a sequence of commands in the following form:
2618 .Bd -literal -offset indent
2627 A defined macro can be invoked explicitly by using the
2631 commands, or implicitly by setting the
2634 .Va folder-hook-FOLDER
2636 Note that interpretation of
2638 depends on how (i.e.,
2640 normal macro, folder hook, account switch) the macro is invoked.
2641 Macros can be deleted via
2643 .Bd -filled -compact -offset indent
2645 Macro behaviour, including option localization, will change in v15.
2646 To be on the absolutely safe side and avoid any surprises it may be wise
2647 to use wrappers that depend on the program version, e.g.,:
2649 .Bd -literal -offset indent
2650 if $version-major < 15
2656 echo "Please reverify macro name (post v15)"
2663 (d) Marks the given message list as
2665 Deleted messages will neither be saved in
2667 nor will they be available for most other commands.
2678 \*(OP\*(OB (disco) If operating in online mode on an IMAP mailbox,
2679 switch to disconnected mode while retaining the mailbox status.
2680 See the description of the
2683 A list of messages may optionally be given as argument;
2684 the respective messages are then read into the cache before the
2685 connection is closed.
2686 Thus `disco *' makes the entire mailbox available for disconnected use.
2691 Deletes the current message and displays the next message.
2692 If there is no next message, \*(UA says
2697 Takes a message list and marks each given message as a draft.
2698 This mark has no technical meaning in the mail system;
2699 it just causes messages to be marked in the header summary,
2700 and makes them specially addressable.
2704 (ec) Echoes its arguments,
2705 resolving special names as documented for the command
2707 The escape sequences
2719 are interpreted just as they are by
2721 (proper quoting provided).
2725 (e) Point the text editor (as defined in
2727 at each message from the given list in turn.
2728 Modified contents are discarded unless the
2735 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2736 conditional \(em if the condition of a preceeding
2738 was false, check the following condition and execute the following block
2739 if it evaluates true.
2744 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2745 conditional \(em if none of the conditions of the preceeding
2749 commands was true, the
2755 (en) Marks the end of an
2756 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2757 conditional execution block.
2761 \*(OP Since \*(UA uses the console as a user interface it can happen
2762 that messages scroll by too fast to become recognized.
2763 Optionally an error message ring queue is available which stores
2764 duplicates of any error message and notifies the user in interactive
2765 sessions whenever a new error has occurred.
2766 The queue is finite: if its maximum size is reached any new message
2767 replaces the eldest.
2770 can be used to manage this message queue: if given
2772 or no argument the queue will be displayed and cleared,
2774 will only clear all messages from the queue.
2778 (ex or x) Exit from \*(UA without changing the active mailbox and skip
2779 any saving of messages in
2781 as well as a possibly tracked command line editor history file.
2785 Show the list of features that have been compiled into \*(UA.
2786 (Outputs the contents of the variable
2793 but open the mailbox readonly.
2797 (fi) The file command switches to a new mailbox.
2798 Without arguments it shows status information of the current mailbox.
2799 If an argument is given, it will write out changes (such as deletions)
2800 the user has made and open a new mailbox.
2801 Some special conventions are recognized for the
2805 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
2807 (number sign) means the previous file,
2809 (percent sign) means the invoking user's system mailbox
2814 means the system mailbox of
2816 (and never the value of
2818 regardless of its actual setting),
2820 (ampersand) means the invoking user's
2830 expands to the same value as
2832 but the file is handled as a system mailbox by, e.g., the
2836 commands, meaning that messages that have been read in the current
2837 session will be moved to the
2839 mailbox instead of simply being flagged as read.
2842 If the name matches one of the strings defined with the command
2844 it is replaced by its long form and expanded.
2845 If the name ends with
2850 it is treated as being compressed with
2855 respectively, and transparently handled through an intermediate
2856 (un)compression step (using a temporary file) with the according
2857 facility, sufficient support provided.
2858 Likewise, if the named file doesn't exist, but a file with one of the
2859 mentioned compression extensions does, then the name is automatically
2860 expanded and the compressed file is used.
2862 Otherwise, if the name ends with an extension for which
2863 .Va file-hook-load-EXTENSION
2865 .Va file-hook-save-EXTENSION
2866 variables are set, then the given hooks will be used to load and save
2868 and \*(UA will work with an intermediate temporary file.
2870 MBOX files (flat file-based mailboxes) are generally locked during file
2871 operations in order to avoid inconsistencies due to concurrent
2873 \*(OPal Mailbox files which \*(UA treats as system or primary mailboxes
2874 will also be protected by so-called dotlock files, the traditional way
2875 of mail spool file locking: for any file
2879 will be created for the duration of the synchronization \(em
2880 as necessary a privilege-separated dotlock child process will be used
2881 to accommodate for necessary privilege adjustments in order to create
2882 the dotlock file in the same directory
2883 and with the same user and group identities as the file of interest.
2886 for fine-tuning the handling of MBOX files.
2890 refers to a directory with the subdirectories
2895 then it is treated as a folder in
2900 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
2901 .Dl \*(OU protocol://[user@]host[:port][/path]
2903 is taken as an Internet mailbox specification.
2904 The \*(OPally supported protocols are
2908 (POP3 with SSL/TLS encrypted transport).
2911 part is valid only for IMAP; there it defaults to
2913 Also see the section
2914 .Sx "On URL syntax and credential lookup" .
2918 contains special characters, in particular
2922 they must be escaped in URL notation \(en the command
2924 can be used to show the necessary conversion.
2925 The optional `path' part applies to IMAP only;
2926 if it is omitted, the default `INBOX' is used.
2928 If \*(UA is connected to an IMAP server,
2929 a name of the form `@mailbox' refers to the `mailbox' on that server,
2930 but otherwise a `@' prefix has no special meaning.
2934 Takes a message list and marks the messages as
2936 ged for urgent/special attention.
2937 This mark has no technical meaning in the mail system;
2938 it just causes messages to be highlighted in the header summary,
2939 and makes them specially addressable.
2948 With no arguments, list the names of the folders in the folder directory.
2949 With an existing folder as an argument,
2950 lists the names of folders below the named folder;
2951 e.\|g. the command `folders @' lists the folders on the base level of
2952 the current IMAP server.
2953 See also the variable
2954 .Va imap-list-depth .
2960 but saves the message in a file named after the local part of the first
2961 recipient's address (instead of in
2968 but saves the message in a file named after the local part of the first
2969 recipient's address (instead of in
2976 but responds to all recipients regardless of the
2981 .It Ic followupsender
2984 but responds to the sender only regardless of the
3000 (f) Takes a list of message specifications and displays a summary of
3001 their message headers, as via
3003 An alias of this command is
3006 .Sx "Specifying messages" .
3012 but saves the message in a file named after the local part of the
3013 recipient's address (instead of in
3018 Takes a message and the address of a recipient
3019 and forwards the message to him.
3020 The text of the original message is included in the new one,
3021 with the value of the
3023 variable preceding it.
3028 commands specify which header fields are included in the new message.
3029 Only the first part of a multipart message is included unless the
3030 .Va forward-as-attachment
3034 is set recipient addresses will be stripped from comments, names etc.
3038 Specifies which header fields are to be ignored with the command
3040 This command has no effect when the
3041 .Va forward-as-attachment
3046 Specifies which header fields are to be retained with the command
3051 This command has no effect when the
3052 .Va forward-as-attachment
3057 Define or list command aliases, so-called ghosts.
3058 Without arguments a list of all currently known aliases is shown.
3059 With one argument the expansion of the given alias is shown.
3060 With two or more arguments a command alias is defined or updated: the
3061 first argument is the name under which the remaining command line should
3062 be accessible, the content of which can be just about anything.
3063 A ghost can be used everywhere a normal command can be used, but always
3064 takes precedence; any arguments that are given to the command alias are
3065 joined onto the alias content, and the resulting string forms the
3066 command line that is, in effect, executed.
3069 .Bd -literal -offset indent
3071 `ghost': no such alias: "xx"
3074 ghost xx "echo hello,"
3083 (h) Show the current group of headers, the size of which depends on
3086 and the style of which can be adjusted with the variable
3088 If a message-specification is given the group of headers containing the
3089 first message therein is shown and the message at the top of the screen
3104 the list of history entries;
3107 argument selects and shows the respective history entry \(en
3110 to accept it, and the history entry will become the new history top.
3111 The default mode if no arguments are given is
3118 Takes a message list and marks each message therein to be saved in the
3119 user's system mailbox instead of in
3121 Does not override the
3124 \*(UA deviates from the POSIX standard with this command, because a
3126 command issued after
3128 will display the following message, not the current one.
3133 (i) Part of the nestable
3134 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
3135 conditional execution construct \(em if the given condition is true then
3136 the encapsulated block is executed.
3137 POSIX only supports the (case-insensitive) conditions
3142 end, all remaining conditions are non-portable extensions; note that
3143 falsely specified conditions cause the execution of the entire
3144 conditional construct until the (matching) closing
3146 command to be suppressed.
3147 The syntax of the nestable
3149 conditional execution construct requires that each condition and syntax
3150 element is surrounded by whitespace.
3152 .Bd -literal -offset indent
3161 The (case-insensitive) condition
3163 erminal will evaluate to true if the standard input is a terminal, i.e.,
3164 in interactive sessions.
3165 Another condition can be any boolean value (see the section
3166 .Sx "INTERNAL VARIABLES"
3167 for textual boolean representations) to mark an enwrapped block as
3170 .Dq always execute .
3171 It is possible to check a variable for existence or compare its
3172 expansion against a user given value or another variable via the
3174 .Pf ( Dq variable next )
3175 conditional trigger character.
3176 The available comparison operators are
3180 (less than or equal to),
3186 (greater than or equal to),
3190 (is substring of) and
3192 (is not substring of).
3193 The values of the left and right hand side are treated as strings and
3194 are compared 8-bit byte-wise, ignoring case according to the rules of
3195 the US-ASCII encoding (therefore, dependend on the active locale,
3196 possibly producing false results for strings in the locale encoding).
3197 Except for the substring checks the comparison will instead be performed
3198 arithmetically if both, the user given value as well as the variable
3199 content, can be parsed as numbers (integers).
3200 An unset variable is treated as the empty string.
3203 When the \*(OPal regular expression support is available, the additional
3209 They treat the right hand side as an extended regular expression that is
3210 matched case-insensitively and according to the active
3212 locale, meaning that strings in the locale encoding should be matched
3216 Conditions can be joined via AND-OR lists (where the AND operator is
3218 and the OR operator is
3220 which have equal precedence and will be evaluated with left
3221 associativity, thus using the same syntax that is known for the
3223 It is also possible to form groups of conditions and lists by enclosing
3224 them in pairs of brackets
3225 .Ql [\ \&.\&.\&.\ ] ,
3226 which may be interlocked within each other, and also be joined via
3230 The results of individual conditions and entire groups may be modified
3231 via unary operators: the unary operator
3233 will reverse the result.
3235 .Bd -literal -offset indent
3239 if $ttycharset == "UTF-8"
3240 echo *ttycharset* is set to UTF-8, case-insensitively
3244 echo These two variables are equal
3246 if $version-major >= 15
3247 echo Running a new version..
3248 if $features =@ "regex"
3249 if $TERM =~ "^xterm\&.*"
3250 echo ..in an X terminal
3253 if [ [ true ] && [ [ $debug ] || [ $verbose ] ] ]
3256 if true && $debug || $verbose
3257 echo Left associativity, as is known from the shell
3259 if ! ! true && ! [ ! $debug && ! $verbose ]
3260 echo Unary operator support
3268 Without arguments the list of ignored header fields is shown,
3269 otherwise the given list of header fields is added to the ignore list:
3270 Header fields in the ignore list are not shown on the terminal when
3271 a message is displayed.
3272 To display a message in its entirety, use the commands
3283 \*(OP\*(OB Sends command strings directly to the current IMAP server.
3284 \*(UA operates always in IMAP `selected state' on the current mailbox;
3285 commands that change this will produce undesirable results and should be
3287 Useful IMAP commands are:
3288 .Bl -tag -offset indent -width ".Ic getquotearoot"
3290 Takes the name of an IMAP mailbox as an argument and creates it.
3292 (RFC 2087) Takes the name of an IMAP mailbox as an argument
3293 and prints the quotas that apply to the mailbox.
3294 Not all IMAP servers support this command.
3296 (RFC 2342) Takes no arguments and prints the Personal Namespaces,
3297 the Other User's Namespaces and the Shared Namespaces.
3298 Each namespace type is printed in parentheses;
3299 if there are multiple namespaces of the same type,
3300 inner parentheses separate them.
3301 For each namespace a prefix and a hierarchy separator is listed.
3302 Not all IMAP servers support this command.
3307 Shows the names of all available commands, alphabetically sorted.
3311 This command can be used to localize changes to variables, meaning that
3312 their state will be reverted to the former one once the covered scope
3314 It can only be used inside of macro definition blocks introduced by
3318 and is interpreted as a boolean (string, see
3319 .Sx "INTERNAL VARIABLES" ) ;
3322 of an account is left once it is switched off again.
3323 .Bd -literal -offset indent
3324 define temporary_settings {
3339 enables change localization and calls
3341 which explicitly resets localization, then any value changes within
3343 will still be reverted by
3348 Reply to messages that come in via known
3351 .Pf ( Ic mlsubscribe )
3352 mailing lists, or pretend to do so (see
3353 .Sx "Mailing lists" ) :
3356 functionality this will actively resort and even remove message
3357 recipients in order to generate a message that is supposed to be send to
3359 For example it will also implicitly generate a
3360 .Ql Mail-Followup-To:
3361 header if that seems useful, regardless of the setting of the variable
3368 but saves the message in a file named after the local part of the first
3369 recipient's address (instead of in
3374 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3375 or asks on standard input if none were given;
3376 then collects the remaining mail content and sends it out.
3380 (mb) The given message list is to be sent to
3382 when \*(UA is quit; this is the default action unless the
3385 \*(ID This command can only be used in a system mailbox (see
3390 Without any arguments the content of the MIME type cache will displayed.
3391 Otherwise each argument defines a complete MIME type specification of
3392 a type that shall be added (prepended) to the cache.
3393 In any event MIME type sources are loaded first as necessary \(en
3394 .Va mimetypes-load-control
3395 can be used to fine-tune which sources are actually loaded.
3396 Refer to the section on
3397 .Sx "The mime.types files"
3398 for more on MIME type specifications and this topic in general.
3399 MIME type unregistration and cache resets can be triggered with
3404 Without arguments the list of all currently defined mailing lists
3405 (and their attributes, if any) is shown.
3406 Otherwise all given arguments (which need not be quoted except for
3407 whitespace) will be added and henceforth be recognized as mailing lists.
3408 Mailing lists may be removed via the command
3411 If the \*(OPal regular expression support is available then mailing
3412 lists may also be specified as (extended) regular expressions (see
3418 Without arguments the list of all currently defined mailing lists which
3419 have a subscription attribute is shown.
3420 Otherwise this attribute will be set for all given mailing lists,
3421 newly creating them as necessary (as via
3423 Subscription attributes may be removed via the command
3432 but moves the messages to a file named after the local part of the
3433 sender address of the first message (instead of in
3440 but marks the messages for deletion if they were transferred
3447 but also displays ignored header fields and all MIME parts.
3455 on the given messages, even in non-interactive mode and as long as the
3456 standard output is a terminal.
3462 \*(OP When used without arguments or if
3464 has been given the content of the
3466 cache is shown, loading it first as necessary,
3469 then the cache will only be initialized and
3471 will remove its contents.
3472 Note that \*(UA will try to load the file only once, use
3473 .Ql Ic netrc Ns \:\0\:clear
3474 to unlock further attempts.
3478 .Sx "On URL syntax and credential lookup" ;
3480 .Sx "The .netrc file"
3481 documents the file format in detail.
3485 Checks for new mail in the current folder without committing any changes
3487 If new mail is present, a message is shown.
3491 the headers of each new message are also shown.
3499 Goes to the next message in sequence and types it.
3500 With an argument list, types the next matching message.
3514 If the current folder is accessed via a network connection, a
3516 command is sent, otherwise no operation is performed.
3522 but also displays ignored header fields and all MIME parts.
3530 on the given messages, even in non-interactive mode and as long as the
3531 standard output is a terminal.
3539 but also pipes ignored header fields and all parts of MIME
3540 .Ql multipart/alternative
3545 (pi) Takes a message list and a shell command
3546 and pipes the messages through the command.
3547 Without an argument the current message is piped through the command
3554 every message is followed by a formfeed character.
3575 (q) Terminates the session, saving all undeleted, unsaved messages in
3578 preserving all messages marked with
3582 or never referenced in the system mailbox,
3583 and removing all other messages from the system mailbox.
3584 If new mail has arrived during the session,
3586 .Dq You have new mail
3588 If given while editing a mailbox file with the command line flag
3590 then the edit file is rewritten.
3591 A return to the shell is effected,
3592 unless the rewrite of edit file fails,
3593 in which case the user can escape with the exit command.
3607 Removes the named folders.
3608 The user is asked for confirmation in interactive mode.
3612 Takes the name of an existing folder
3613 and the name for the new folder
3614 and renames the first to the second one.
3615 Both folders must be of the same type
3616 and must be located on the current server for IMAP.
3620 (R) Reply to originator.
3621 Does not reply to other recipients of the original message.
3623 will exchange this command with
3627 is set the recipient address will be stripped from comments, names etc.
3631 (r) Take a message and group-responds to it by addressing the sender
3634 .Va followup-to-honour ,
3637 .Va recipients-in-cc
3638 influence response behaviour.
3641 offers special support for replying to mailing lists.
3644 is set recipient addresses will be stripped from comments, names etc.
3657 but initiates a group-reply regardless of the value of
3664 but responds to the sender only regardless of the value of
3671 but does not add any header lines.
3672 This is not a way to hide the sender's identity,
3673 but useful for sending a message again to the same recipients.
3677 Takes a list of messages and a user name
3678 and sends each message to the named user.
3680 and related header fields are prepended to the new copy of the message.
3698 .It Ic respondsender
3704 (ret) Without arguments the list of retained header fields is shown,
3705 otherwise the given list of header fields is added to the retain list:
3706 Header fields in the retain list are shown on the terminal when
3707 a message is displayed, all other header fields are suppressed.
3708 To display a message in its entirety, use the commands
3717 takes precedence over the mentioned.
3723 but saves the messages in a file named after the local part of the
3724 sender of the first message instead of (in
3726 and) taking a filename argument.
3730 (s) Takes a message list and a filename and appends each message in turn
3731 to the end of the file.
3732 If no filename is given, the
3735 The filename in quotes, followed by the generated character count
3736 is echoed on the user's terminal.
3737 If editing a system mailbox the messages are marked for deletion.
3738 Filename interpretation as described for the
3740 command is performed.
3757 Header fields thus marked are filtered out when saving a message by
3759 or when automatically saving to
3761 This command should only be applied to header fields that do not contain
3762 information needed to decode the message,
3763 as MIME content fields do.
3764 If saving messages on an IMAP account ignoring fields makes it
3765 impossible to copy the data directly on the server,
3766 thus operation usually becomes much slower.
3778 Header fields thus marked are the only ones saved with a message when
3781 or when automatically saving to
3786 The use of this command is strongly discouraged since it may strip
3787 header fields that are needed to decode the message correctly.
3791 Takes a message specification (list) and displays a header summary of
3792 all matching messages, as via
3794 This command is an alias of
3797 .Sx "Specifying messages" .
3801 Takes a message list and marks all messages as having been read.
3805 (se) Without arguments this command shows all variables and their
3806 values which are currently known to \*(UA.
3807 Setting any of the variables
3811 changes the output format to BSD style, otherwise a properly quoted
3812 listing is produced.
3817 has been set twice then the listing is modified to mark out assembled
3820 Otherwise modifies (set and unsets) the given variables.
3821 Arguments are of the form
3823 (no space before or after
3827 if there is no value.
3828 Quotation marks may be placed around any part of the assignment
3829 statement to quote blanks or tabs, e.g.,
3831 .Dl set indentprefix="->"
3833 If an argument begins with
3837 the effect is the same as invoking the
3839 command with the remaining part of the variable
3840 .Pf ( Ql unset save ) .
3846 except that the variables are also exported into the program environment;
3847 since this task requires native host support the command will always
3848 report error if that is not available (but still act like
3851 This operation is a no-op unless all resource files have been loaded.
3857 (sh) Invokes an interactive version of the shell.
3861 Without arguments the list of all currently defined shortcuts is
3863 Otherwise all given arguments (which need not be quoted except for
3864 whitespace) are treated as pairs of shortcuts and their expansions,
3865 creating new or changing already existing shortcuts, as necessary.
3866 Shortcuts may be removed via the command
3868 The expansion strings should be in the syntax that has been described
3877 but performs neither MIME decoding nor decryption, so that the raw
3878 message text is shown.
3882 (si) Shows the size in characters of each message of the given
3887 Shows the current sorting criterion when used without an argument.
3888 Otherwise creates a sorted representation of the current folder,
3891 command and the addressing modes such that they refer to messages in
3893 Message numbers are the same as in regular mode.
3897 a header summary in the new order is also displayed.
3898 Automatic folder sorting can be enabled by setting the
3900 variable, as in, e.g.,
3901 .Ql set autosort=thread .
3902 Possible sorting criterions are:
3904 .Bl -tag -compact -offset indent -width "subject"
3906 Sort the messages by their
3908 field, that is by the time they were sent.
3910 Sort messages by the value of their
3912 field, that is by the address of the sender.
3915 variable is set, the sender's real name (if any) is used.
3917 Sort the messages by their size.
3919 \*(OP Sort the message by their spam score, as has been classified by
3922 Sort the messages by their message status.
3924 Sort the messages by their subject.
3926 Create a threaded display.
3928 Sort messages by the value of their
3930 field, that is by the address of the recipient.
3933 variable is set, the recipient's real name (if any) is used.
3938 (so) The source command reads commands from a file.
3944 is that this command will not generate an error if the given file
3945 argument cannot be opened successfully.
3946 This can matter in, e.g., resource files, since loading of those is
3947 stopped when an error is encountered.
3951 \*(OP Takes a list of messages and clears their
3957 \*(OP Takes a list of messages and causes the
3959 to forget it has ever used them to train its Bayesian filter.
3960 Unless otherwise noted the
3962 flag of the message is inspected to chose wether a message shall be
3970 \*(OP Takes a list of messages and informs the Bayesian filter of the
3974 This also clears the
3976 flag of the messages in question.
3980 \*(OP Takes a list of messages and rates them using the configured
3981 .Va spam-interface ,
3982 without modifying the messages, but setting their
3984 flag as appropriate; because the spam rating headers are lost the rate
3985 will be forgotten once the mailbox is left.
3986 Refer to the manual section
3988 for the complete picture of spam handling in \*(UA.
3992 \*(OP Takes a list of messages and sets their
3998 \*(OP Takes a list of messages and informs the Bayesian filter of the
4004 flag of the messages in question.
4013 Create a threaded representation of the current folder,
4014 i.\|e. indent messages that are replies to other messages in the header
4015 display and change the
4017 command and the addressing modes such that they refer to messages in the
4019 Message numbers are the same as in unthreaded mode.
4023 a header summary in threaded order is also displayed.
4027 (to) Takes a message list and displays the top few lines of each.
4028 The number of lines shown is controlled by the variable
4030 and defaults to five.
4034 (tou) Takes a message list and marks the messages for saving in
4036 \*(UA deviates from the POSIX standard with this command,
4039 command will display the following message instead of the current one.
4045 but also displays out ignored header fields and all parts of MIME
4046 .Ql multipart/alternative
4051 (t) Takes a message list and types out each message on the user's
4057 For MIME multipart messages, all parts with a content type of
4061 are shown, the other are hidden except for their headers.
4062 Messages are decrypted and converted to the terminal character set
4067 Delete all given accounts.
4068 An error message is shown if a given account is not defined.
4071 will discard all existing accounts.
4075 (una) Takes a list of names defined by alias commands
4076 and discards the remembered groups of users.
4079 will discard all existing aliases.
4083 Takes a message list and marks each message as not having been answered.
4087 Only applicable to threaded mode.
4088 Takes a message list and makes the message and all replies to it visible
4089 in header summaries again.
4090 When a message becomes the current message,
4091 it is automatically made visible.
4092 Also when a message with collapsed replies is displayed,
4093 all of these are automatically uncollapsed.
4097 Undefine all given macros.
4098 An error message is shown if a given macro is not defined.
4101 will discard all existing macros.
4105 (u) Takes a message list and marks each message as not being deleted.
4109 Takes a message list and
4115 Takes a message list and marks each message as not being
4120 Removes the header field names from the list of ignored fields for the
4125 will remove all fields.
4129 Removes the header field names from the list of retained fields for the
4134 will remove all fields.
4138 Remove all the given command
4142 will remove all ghosts.
4146 Removes the header field names from the list of ignored fields.
4149 will remove all fields.
4153 Delete all given MIME types, e.g.,
4154 .Ql unmimetype text/plain
4155 will remove all registered specifications for the MIME type
4159 will discard all existing MIME types, just as will
4161 but which also reenables cache initialization via
4162 .Va mimetypes-load-control .
4166 Forget about all the given mailing lists.
4169 will remove all lists.
4174 .It Ic unmlsubscribe
4175 Remove the subscription attribute from all given mailing lists.
4178 will clear the attribute from all lists which have it set.
4189 Takes a message list and marks each message as not having been read.
4193 Removes the header field names from the list of retained fields.
4196 will remove all fields.
4200 Removes the header field names from the list of ignored fields for
4204 will remove all fields.
4208 Removes the header field names from the list of retained fields for
4212 will remove all fields.
4216 (uns) Takes a list of option names and discards their remembered values;
4224 except that the variables are also removed from the program environment;
4225 since this task requires native host support the command will always
4226 report error if that is not available (but still act like
4229 This operation is a no-op unless all resource files have been loaded.
4235 Deletes the shortcut names given as arguments.
4238 will remove all shortcuts.
4242 Disable sorted or threaded mode
4248 return to normal message order and,
4252 displays a header summary.
4262 Decode the given URL-encoded string arguments and show the results.
4263 Note the resulting strings may not be valid in the current locale, see
4268 URL-encode the given arguments and show the results.
4269 Because the arguments effectively are in the character set of the
4270 current locale the results will vary accordingly unless the input solely
4271 consists of characters in the portable character set, see
4272 .Sx "Character sets" .
4276 Edit the values of or create the given variable(s) in the
4278 Boolean variables cannot be edited.
4282 Show informations about all the given variables.
4283 \*(UA knows about a finite set of known builtin variables that are
4284 subdivided further in boolean and value variants;
4285 they may have special properties, like
4287 (setting may not be changed) and
4289 meaning that the value is generated on-the-fly as necessary.
4290 Beside those known variables an infinite number of unknown, so-called
4292 variables, which are expected to be able to store values, may exist.
4293 .Bd -literal -offset indent
4295 ? varshow sendwait version-major foo bar
4296 "sendwait": (73) boolean: set=1 (ENVIRON=0)
4297 "version-major": (192) value, read-only, virtual:\e
4298 set=1 (ENVIRON=0) value<14>
4299 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4300 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4305 \*(OP Takes a message list and verifies each message.
4306 If a message is not a S/MIME signed message,
4307 verification will fail for it.
4308 The verification process checks if the message was signed using a valid
4310 if the message sender's email address matches one of those contained
4311 within the certificate,
4312 and if the message content has been altered.
4316 (v) Takes a message list and invokes the display editor on each message.
4317 Modified contents are discarded unless the
4323 (w) For conventional messages the body without all headers is written.
4324 The output is decrypted and converted to its native format as necessary.
4325 If the output file exists, the text is appended.
4326 If a message is in MIME multipart format its first part is written to
4327 the specified file as for conventional messages,
4328 and the user is asked for a filename to save each other part.
4329 For convience saving of each part may be skipped by giving an empty value;
4330 the same result can also be achieved by writing it to
4332 For the second and subsequent parts a leading
4334 character causes the part to be piped to the remainder of the user input
4335 interpreted as a shell command;
4336 otherwise the user input is expanded as usually for folders,
4337 e.g., tilde expansion is performed.
4338 In non-interactive mode, only the parts of the multipart message
4339 that have a filename given in the part header are written,
4340 the others are discarded.
4341 The original message is never marked for deletion in the originating
4344 the contents of the destination file are overwritten if the file
4346 No special handling of compressed files is performed.
4355 \*(UA presents message headers in windowfuls as described under the
4358 This command scrolls to the next window of messages.
4359 If an argument is given,
4360 it specifies the window to use.
4361 A number prefixed by
4365 indicates that the window is calculated in relation to the current position.
4366 A number without a prefix specifies an absolute window number,
4369 lets \*(UA scroll to the last window of messages.
4375 but scrolls to the next or previous window that contains at least one
4384 .\" .Sh TILDE ESCAPES {{{
4387 Here is a summary of the tilde escapes,
4388 which are used to perform special functions when composing messages.
4389 Tilde escapes are only recognized at the beginning of lines.
4392 is somewhat of a misnomer since the actual escape character can be
4393 changed by adjusting the option
4396 .Bl -tag -width ".Ic __ filename"
4399 Insert the string of text in the message prefaced by a single
4401 (If the escape character has been changed,
4402 that character must be doubled
4403 in order to send it at the beginning of a line.)
4406 .It Ic ~! Ar command
4407 Execute the indicated shell
4409 then return to the message.
4413 Same effect as typing the end-of-file character.
4416 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4417 Execute the given \*(UA command.
4418 Not all commands, however, are allowed.
4422 Write a summary of command escapes.
4425 .It Ic ~< Ar filename
4430 .It Ic ~<! Ar command
4432 is executed using the shell.
4433 Its standard output is inserted into the message.
4436 .It Ic ~@ Op Ar filename...
4437 With no arguments, edit the attachment list interactively.
4438 If an attachment's file name is left empty,
4439 that attachment is deleted from the list.
4440 When the end of the attachment list is reached,
4441 \*(UA will ask for further attachments until an empty name is given.
4442 If a given file name solely consists of the number sign
4444 followed by a valid message number of the currently active mailbox, then
4445 the given message is attached as a MIME
4447 and the rest of this section does not apply.
4449 If character set conversion has been compiled into \*(UA, then this mode
4450 gives the user the option to specify input and output character sets,
4451 unless the file extension indicates binary content, in which case \*(UA
4452 asks wether this step shall be skipped for the attachment in question.
4453 If not skipped, then the charset that succeeds to represent the
4454 attachment data will be used in the
4456 MIME parameter of the mail message:
4458 .Bl -bullet -compact
4460 If input and output character sets are specified, then the conversion is
4461 performed on the fly.
4462 The user will be asked repeatedly until the desired conversion succeeds.
4464 If only an output character set is specified, then the input is assumed
4467 charset and will be converted to the given output charset on the fly.
4468 The user will be asked repeatedly until the desired conversion succeeds.
4470 If no character sets are specified at all then the algorithm that is
4471 documented in the section
4472 .Sx "Character sets"
4473 is applied, but directly and on the fly.
4474 The user will be asked repeatedly until the desired conversion succeeds.
4476 Finally, if an input-, but no output character set is specified, then no
4477 conversion is ever performed, but the
4479 MIME parameter value will still be set to the user input.
4481 The character set selection loop can be left by typing
4483 i.e., causing an interrupt.
4484 .\" \*(OU next sentence
4485 Note that before \*(UA version 15.0 this terminates the entire
4486 current attachment selection, not only the character set selection.
4489 Without character set conversion support, \*(UA will ask for the input
4490 character set only, and it'll set the
4492 MIME parameter value to the given input, if any;
4493 if no user input is seen then the
4495 character set will be used for the parameter value instead.
4496 Note that the file extension check isn't performed in this mode, since
4497 no conversion will take place anyway.
4499 Note that in non-interactive mode, for reproduceabilities sake, there
4500 will always be two questions for each attachment, regardless of wether
4501 character set conversion is available and what the file extension is.
4502 The first asks for the filename, and the second asks for the input
4503 character set to be passed through to the corresponding MIME parameter;
4504 no conversion will be tried if there is input to the latter question,
4505 otherwise the usual conversion algorithm, as above, is applied.
4506 For message attachments, the answer to the second question is completely
4511 arguments are specified for the
4513 command they are treated as a comma separated list of files,
4514 which are all expanded and appended to the end of the attachment list.
4515 (Filenames with commas, or with leading or trailing whitespace can only
4516 be added via the command line or the first method.
4517 Message attachments can only be added via the first method;
4518 filenames which clash with message numbers can only be added via the
4519 command line or the second method.)
4520 In this mode the (text) attachments are assumed to be in
4522 encoding, and will be evaluated as documented in the section
4523 .Sx "Character sets" .
4527 Inserts the string contained in the
4530 .Ql Ic ~i Ns \0Sign ) .
4531 The escape sequences tabulator
4539 Inserts the string contained in the
4542 .Ql Ic ~i Ns \0sign ) .
4543 The escape sequences tabulator
4550 .It Ic ~b Ar name ...
4551 Add the given names to the list of blind carbon copy recipients.
4554 .It Ic ~c Ar name ...
4555 Add the given names to the list of carbon copy recipients.
4559 Read the file specified by the
4561 variable into the message.
4565 Invoke the text editor on the message collected so far.
4566 After the editing session is finished,
4567 the user may continue appending text to the message.
4570 .It Ic ~F Ar messages
4571 Read the named messages into the message being sent, including all
4572 message headers and MIME parts.
4573 If no messages are specified, read in the current message.
4576 .It Ic ~f Ar messages
4577 Read the named messages into the message being sent.
4578 If no messages are specified, read in the current message.
4582 lists are used to modify the message headers.
4583 For MIME multipart messages,
4584 only the first displayable part is included.
4588 Edit the message header fields
4594 by typing each one in turn and allowing the user to edit the field.
4595 The default values for these fields originate from the
4596 .Va from , replyto , sender
4603 Edit the message header fields
4609 by typing each one in turn and allowing the user to edit the field.
4612 .It Ic ~i Ar variable
4613 Insert the value of the specified variable into the message,
4614 adding a newline character at the end.
4615 The message remains unaltered if the variable is unset or empty.
4616 The escape sequences tabulator
4623 .It Ic ~M Ar messages
4624 Read the named messages into the message being sent,
4627 If no messages are specified, read the current message.
4630 .It Ic ~m Ar messages
4631 Read the named messages into the message being sent,
4634 If no messages are specified, read the current message.
4638 lists are used to modify the message headers.
4639 For MIME multipart messages,
4640 only the first displayable part is included.
4644 Display the message collected so far,
4645 prefaced by the message header fields
4646 and followed by the attachment list, if any.
4650 Abort the message being sent,
4651 copying it to the file specified by the
4658 .It Ic ~R Ar filename
4659 Read the named file into the message, indented by
4663 .It Ic ~r Ar filename
4664 Read the named file into the message.
4668 Cause the named string to become the current subject field.
4671 .It Ic ~t Ar name ...
4672 Add the given name(s) to the direct recipient list.
4675 .It Ic ~U Ar messages
4676 Read in the given / current message(s) excluding all headers, indented by
4680 .It Ic ~u Ar messages
4681 Read in the given / current message(s), excluding all headers.
4685 Invoke an alternate editor (defined by the
4687 option) on the message collected so far.
4688 Usually, the alternate editor will be a screen editor.
4689 After the editor is quit,
4690 the user may resume appending text to the end of the message.
4693 .It Ic ~w Ar filename
4694 Write the message onto the named file.
4696 the message is appended to it.
4702 except that the message is not saved at all.
4705 .It Ic ~| Ar command
4706 Pipe the message through the specified filter command.
4707 If the command gives no output or terminates abnormally,
4708 retain the original text of the message.
4711 is often used as a rejustifying filter.
4716 .\" .Sh INTERNAL VARIABLES {{{
4717 .Sh "INTERNAL VARIABLES"
4719 Internal \*(UA variables are controlled via the
4723 commands; prefixing a variable name with the string
4727 has the same effect as using
4733 Creation or editing of variables can be performed in the
4738 will give more insight on the given variable(s), and
4740 when called without arguments, will show a listing of all variables.
4741 Variables are also implicitly inherited from the program
4743 and can be set explicitly via the command line option
4747 Two different kind of variables exist.
4748 There are boolean variables, which can only be in one of the two states
4752 and value variables with a(n optional) string value.
4753 For the latter proper quoting is necessary upon assignment time:
4754 To embed whitespace (space and tabulator) in a value it either needs to
4755 be escaped with a backslash character, or the entire value must be
4756 enclosed in (double or single) quotation marks;
4757 To use quotation marks identical to those used to enclose the value,
4758 escape them with a backslash character.
4759 The backslash character has no special meaning except in these cases.
4761 .Bd -literal -offset indent
4762 set one=val\e 1 two="val 2" \e
4763 three='val "3"' four='val \e'4\e''
4764 varshow one two three four
4765 unset one two three four
4769 Dependent upon the actual option the string values will be interpreted
4770 as numbers, colour names, normal text etc., but there also exists
4771 a special kind of string value, the
4772 .Dq boolean string ,
4773 which must either be a decimal integer (in which case
4777 and any other value is true) or any of the (case-insensitive) strings
4782 for a false boolean and
4787 for a true boolean; a special kind of boolean string is the
4789 which is a boolean string that can optionally be prefixed with the
4790 (case-insensitive) term
4794 which causes prompting of the user in interactive mode, with the given
4795 boolean as the default value.
4797 .\" .Ss "Initial settings" {{{
4798 .\" (Keep in SYNC: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
4799 .Ss "Initial Settings"
4801 The standard POSIX 2008/Cor 1-2013 mandates the following initial
4807 .Pf no Va autoprint ,
4821 .Pf no Va ignoreeof ,
4823 .Pf no Va keepsave ,
4825 .Pf no Va outfolder ,
4830 (note that \*(UA deviates from the standard by using
4834 special prompt escape results in
4842 .Pf no Va sendwait ,
4851 Notes: \*(UA doesn't support the
4853 variable \(en use command line options or
4854 .Va sendmail-arguments
4855 to pass options through to a MTA.
4856 And the default global
4858 file (which is loaded unless the
4860 command line flag has been used or the
4861 .Ev NAIL_NO_SYSTEM_RC
4862 environment variable is set) bends those initial settings a bit, e.g.,
4863 it sets the variables
4868 to name a few, calls
4870 etc., and should thus be taken into account.
4873 .\" .Ss "Variables" {{{
4876 .Bl -tag -width ".It Va _utoprin_"
4878 .It Va add-file-recipients
4879 \*(BO When file or pipe recipients have been specified,
4880 mention them in the corresponding address fields of the message instead
4881 of silently stripping them from their recipient list.
4882 By default such addressees are not mentioned.
4884 .Mx Va agent-shell-lookup
4885 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
4887 \*(IN\*(OP Account passwords can be fetched via an external agent
4888 program in order to permit encrypted password storage \(en see
4889 .Sx "On URL syntax and credential lookup"
4890 for more on credential lookup.
4891 If this is set then the content is interpreted as a shell command the
4892 output of which (with newline characters removed) is treated as the
4893 account password shall the command succeed (and have produced non-empty
4894 non-newline output); e.g., via
4896 .Bd -literal -offset indent
4897 $ echo PASSWORD > .pass
4899 $ eval `gpg-agent --daemon \e
4900 --pinentry-program=/usr/bin/pinentry-curses \e
4901 --max-cache-ttl 99999 --default-cache-ttl 99999`
4902 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
4906 A couple of environment variables will be set for the agent:
4908 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
4910 The temporary directory that \*(UA uses.
4911 Usually identical to
4913 but guaranteed to be set and usable by child processes;
4914 to ensure the latter condition for
4920 for which the password is looked up.
4921 .It Ev NAIL_USER_ENC
4922 The URL percent-encoded variant of
4925 The plain machine hostname of the user account.
4926 .It Ev NAIL_HOST_PORT
4929 (hostname possibly including port) of the user account.
4934 \*(BO Causes only the local part to be evaluated
4935 when comparing addresses.
4939 \*(BO Causes messages saved in
4941 to be appended to the end rather than prepended.
4942 This should always be set.
4946 \*(BO Causes \*(UA to prompt for the subject of each message sent.
4947 If the user responds with simply a newline,
4948 no subject field will be sent.
4952 \*(BO Causes the prompts for
4956 lists to appear after the message has been edited.
4960 \*(BO If set, \*(UA asks for files to attach at the end of each message,
4961 shall the list be found empty at that time.
4962 An empty line finalizes the list.
4966 \*(BO Causes the user to be prompted for carbon copy recipients
4967 (at the end of each message if
4971 are set) shall the list be found empty (at that time).
4972 An empty line finalizes the list.
4976 \*(BO Causes the user to be prompted for blind carbon copy
4977 recipients (at the end of each message if
4981 are set) shall the list be found empty (at that time).
4982 An empty line finalizes the list.
4986 \*(BO\*(OP Causes the user to be prompted if the message is to be
4987 signed at the end of each message.
4990 variable is ignored when this variable is set.
4994 \*(BO Alternative name for
5001 .It Va attachment-ask-content-description , \
5002 attachment-ask-content-disposition , \
5003 attachment-ask-content-id , \
5004 attachment-ask-content-type
5005 \*(BO If set then the user will be prompted for some attachment
5006 information when editing the attachment list.
5007 It is advisable to not use these but for the first of the variables;
5008 even for that it has to be noted that the data is used
5014 A sequence of characters to display in the
5018 as shown in the display of
5020 each for one type of messages (see
5021 .Sx "Message states" ) ,
5022 with the default being
5025 .Ql NU\ \ *HMFAT+\-$~
5028 variable is set, in the following order:
5030 .Bl -tag -compact -offset indent -width ".It Ql _"
5052 start of a collapsed thread.
5054 an uncollapsed thread (TODO ignored for now).
5058 classified as possible spam.
5064 Specifies a list of recipients to which a blind carbon copy of each
5065 outgoing message will be sent automatically.
5069 Specifies a list of recipients to which a carbon copy of each outgoing
5070 message will be sent automatically.
5074 \*(BO Causes threads to be collapsed automatically when threaded mode
5081 \*(BO Causes the delete command to behave like
5083 thus, after deleting a message the next one will be typed automatically.
5087 \*(BO\*(OB Causes threaded mode (see the
5089 command) to be entered automatically when a folder is opened.
5091 .Ql autosort=thread .
5095 Causes sorted mode (see the
5097 command) to be entered automatically with the value of this option as
5098 sorting method when a folder is opened, e.g.,
5099 .Ql set autosort=thread .
5103 \*(BO Enables the substitution of
5105 by the contents of the last command line in shell escapes.
5108 .It Va batch-exit-on-error
5109 \*(BO If the batch mode has been enabled via the
5111 command line option, then this variable will be consulted whenever \*(UA
5112 completes one operation (returns to the command prompt); if it is set
5113 then \*(UA will terminate if the last operation generated an error.
5117 \*(BO Causes automatic display of a header summary after executing a
5123 \*(BO Sets some cosmetical features to traditional BSD style;
5124 has the same affect as setting
5126 and all other variables prefixed with
5128 it also changes the meaning of the \*(UA specific
5131 escape sequence and changes behaviour of
5133 (which doesn't exist in BSD).
5137 \*(BO Changes the letters shown in the first column of a header
5138 summary to traditional BSD style.
5142 \*(BO Changes the display of columns in a header summary to traditional
5147 \*(BO Changes some informational messages to traditional BSD style.
5153 field to appear immediately after the
5155 field in message headers and with the
5157 .Sx "TILDE ESCAPES" .
5161 \*(BO Changes the output format of the
5163 command to traditional BSD style.
5167 The value that should appear in the
5171 MIME header fields when no character set conversion of the message data
5173 This defaults to US-ASCII, and the chosen character set should be
5174 US-ASCII compatible.
5178 \*(OP The default 8-bit character set that is used as an implicit last
5179 member of the variable
5181 This defaults to UTF-8.
5182 If no character set conversion capabilities are available in \*(UA then
5183 the only supported character set is
5185 Refer to the section
5186 .Sx "Character sets"
5187 for the complete picture of character set conversion in \*(UA.
5190 .It Va charset-unknown-8bit
5191 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5193 the content of a mail message by using a character set with the name
5195 Because of the unclassified nature of this character set \*(UA will not
5196 be capable to convert this character set to any other character set.
5197 If this variable is set any message part which uses the character set
5199 is assumed to really be in the character set given in the value,
5200 otherwise the (final) value of
5202 is used for this purpose.
5206 The default value for the
5211 .It Va colour-disable
5212 \*(BO\*(OP Forcefully disable usage of colours.
5213 Also see the section
5214 .Sx "Coloured message display" .
5218 \*(OP The colour specification for so-called
5222 .Sx "Coloured message display"
5223 for the format of the value.
5226 .It Va colour-header
5227 \*(OP The colour specification for header lines.
5230 .It Va colour-msginfo
5231 \*(OP The colour specification for the introductional message info line.
5235 \*(BO\*(OP Wether colour shall be used for output that is paged through
5237 Note that pagers may need special flags, e.g.,
5245 in order to support colours; therefore \*(UA will inspect the variable
5247 \(en if that starts with the string
5249 a non-existing environment variable
5256 will optionally be set to
5258 Also see the section
5259 .Sx "Coloured message display"
5263 .It Va colour-partinfo
5264 \*(OP The colour specification for MIME part info lines.
5268 \*(OP A comma-separated list of
5270 inals for which coloured message display can be used.
5271 Entries only need to be added if the string
5273 isn't part of the terminal name itself; the default value is
5275 .\" (Keep in SYNC: ./nail.h:COLOUR_TERMS, ./nail.1:*colour-terms*"!)
5276 .Dl aterm,cons25,gnome,konsole,\:kterm,\:linux,\:\
5277 rxvt,\:rxvt-unicode,\:screen,\:sun,\:vt100,\:vt220,\:wsvt25,\:xterm
5280 .It Va colour-uheader
5281 \*(OP The colour specification for those header lines that have been
5283 .Va colour-user-headers
5286 .Sx "Coloured message display" .
5289 .It Va colour-user-headers
5290 A comma separated list of (case-insensitive) header names which should
5291 be colourized with the alternative
5294 The default value is
5299 In a(n interactive) terminal session, then if this valued option is set
5300 it'll be used as a threshold to determine how many lines the given
5301 output has to span before it will be displayed via the configured
5305 can be forced by setting this to the value
5307 setting it without a value will deduce the current height of the
5308 terminal screen to compute the treshold (see
5318 the message date, if any is to be displayed according to the format of
5320 is by default taken from the
5322 line of the message.
5323 If this variable is set the date as given in the
5325 header field is used instead, converted to local time.
5326 To control the display format of the date assign a valid
5331 format should not be used, because \*(UA doesn't take embedded newlines
5332 into account when calculating how many lines fit onto the screen.)
5334 .Va datefield-markout-older .
5337 .It Va datefield-markout-older
5338 This option, when set in addition to
5342 messages (concept is rather comparable to the
5344 option of the POSIX utility
5346 The content interpretation is identical to
5351 \*(BO Enables debug messages and obsoletion warnings, disables the
5352 actual delivery of messages and also implies
5359 \*(BY\*(OP\*(OB When an IMAP mailbox is selected and this variable is set,
5360 no connection to the server is initiated.
5361 Instead, data is obtained from the local cache (see
5364 Mailboxes that are not present in the cache
5365 and messages that have not yet entirely been fetched from the server
5367 to fetch all messages in a mailbox at once,
5369 .No ` Ns Li copy * /dev/null Ns '
5370 can be used while still in connected mode.
5371 Changes that are made to IMAP mailboxes in disconnected mode are queued
5372 and committed later when a connection to that server is made.
5373 This procedure is not completely reliable since it cannot be guaranteed
5374 that the IMAP unique identifiers (UIDs) on the server still match the
5375 ones in the cache at that time.
5378 when this problem occurs.
5380 .It Va disconnected-USER@HOST
5381 The specified account is handled as described for the
5384 but other accounts are not affected.
5387 .It Va disposition-notification-send
5389 .Ql Disposition-Notification-To:
5390 header (RFC 3798) with the message.
5394 .\" TODO .It Va disposition-notification-send-HOST
5396 .\".Va disposition-notification-send
5397 .\" for SMTP accounts on a specific host.
5398 .\" TODO .It Va disposition-notification-send-USER@HOST
5400 .\".Va disposition-notification-send
5401 .\"for a specific account.
5405 \*(BO When dot is set, a period
5407 on a line by itself during message input in (interactive) compose mode
5408 will be treated as end-of-message (in addition to the normal end-of-file
5417 .It Va dotlock-ignore-error
5418 \*(BO\*(OP Synchronization of mailboxes which \*(UA treats as system
5419 mailboxes (see the command
5421 will be protected with so-called dotlock files\(emthe traditional mail
5422 spool file locking method\(emin addition to system file locking.
5423 Because \*(UA ships with a privilege-separated dotlock creation program
5424 that should always be able to create such a dotlock file there is no
5425 good reason to ignore dotlock file creation errors, and thus these are
5426 fatal unless this variable is set.
5430 \*(BO If this variable is set then the editor is started automatically
5431 when a message is composed in interactive mode, as if the
5437 variable is implied for this automatically spawned editor session.
5441 \*(BO When a message is edited while being composed,
5442 its header is included in the editable text.
5453 fields are accepted within the header, other fields are ignored.
5457 \*(BO When entering interactive mode \*(UA normally writes
5458 .Dq \&No mail for user
5459 and exits immediately if a mailbox is empty or doesn't exist.
5460 If this option is set \*(UA starts even with an empty or nonexistent
5461 mailbox (the latter behaviour furtherly depends upon
5467 Suggestion for the MIME encoding to use in outgoing text messages
5469 Valid values are the default
5470 .Ql quoted-printable ,
5475 may cause problems when transferring mail messages over channels that
5476 are not ESMTP (RFC 1869) compliant.
5477 If there is no need to encode a message,
5479 transfer mode is always used regardless of this variable.
5480 Binary data is always encoded as
5485 If defined, the first character of this option
5486 gives the character to use in place of
5489 .Sx "TILDE ESCAPES" .
5493 If not set then file and command pipeline targets are not allowed,
5494 and any such address will be filtered out, giving a warning message.
5495 If set without a value then all possible recipient address
5496 specifications will be accepted \(en see the section
5497 .Sx "On sending mail, and non-interactive mode"
5499 To accept them, but only in interactive mode, or when tilde commands
5500 were enabled explicitly by using one of the command line options
5504 set this to the (case-insensitive) value
5506 (note right now this is actually like setting
5507 .Ql restrict,-all,+name,+addr ) .
5509 In fact the value is interpreted as a comma-separated list of values.
5512 then the existence of disallowed specifications is treated as a hard
5513 send error instead of only filtering them out.
5514 The remaining values specify wether a specific type of recipient
5515 address specification is allowed (optionally indicated by a plus sign
5517 prefix) or disallowed (prefixed with a hyphen
5521 addresses all possible address specifications,
5525 command pipeline targets,
5527 plain user names and (MTA) aliases (\*(OB
5529 may be used as an alternative syntax to
5534 These kind of values are interpreted in the given order, so that
5535 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5536 will cause hard errors for any non-network address recipient address
5537 unless \*(UA is in interactive mode or has been started with the
5541 command line option; in the latter case(s) any address may be used, then.
5545 Unless this variable is set additional mail-transfer-agent (MTA)
5546 arguments from the command line, as can be given after a
5548 separator, are ignored due to safety reasons.
5549 However, if set to the special value
5551 then the presence of additional MTA arguments is treated as a hard
5552 error that causes \*(UA to exit with failure status.
5553 A lesser strict variant is the otherwise identical
5555 which does accept such arguments in interactive mode, or if tilde
5556 commands were enabled explicitly by using one of the command line options
5563 \*(RO Information on the features compiled into \*(UA \(en the content
5564 of this variable is identical to the output of the command
5569 \*(BO This option reverses the meanings of a set of reply commands,
5570 turning the lowercase variants, which by default address all recipients
5571 included in the header of a message
5572 .Pf ( Ic reply , respond , followup )
5573 into the uppercase variants, which by default address the sender only
5574 .Pf ( Ic Reply , Respond , Followup )
5577 .Ic replysender , respondsender , followupsender
5579 .Ic replyall , respondall , followupall
5580 are not affected by the current setting of
5585 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5586 It is possible to install file hooks which will be used by the
5588 command in order to be able to transparently handle (through an
5589 intermediate temporary file) files with specific
5591 s: the variable values can include shell snippets and are expected to
5592 write data to standard output / read data from standard input,
5594 \*(ID The variables may not be changed while there is a mailbox
5596 .Bd -literal -offset indent
5597 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5598 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5599 record=+null-sent.xy
5604 The name of the directory to use for storing folders of messages.
5605 All folder names that begin with
5607 refer to files below it.
5608 The same special conventions as documented for the
5610 command may be used when specifying a new value for
5612 but be aware that the expansion is fully performed immediately.
5613 E.g., if the expanded name refers to an IMAP account, all names that
5614 begin with `+' refer to IMAP mailboxes below the
5618 Note: some IMAP servers do not accept the creation of mailboxes in
5619 the hierarchy base, but require that they are created as subfolders of
5620 `INBOX' \(en with such servers a folder name of the form
5622 .Dl imaps://mylogin@imap.myisp.example/INBOX.
5624 should be used (the last character is the server's hierarchy delimiter).
5625 Folder names prefixed by `+' will then refer to folders below `INBOX',
5626 while folder names prefixed by `@' refer to folders below the hierarchy
5630 namespace command for a method to detect the appropriate prefix and
5635 This variable can be set to the name of a
5637 macro which will be called whenever a
5640 The macro will also be invoked when new mail arrives,
5641 but message lists for commands executed from the macro
5642 only include newly arrived messages then.
5645 are activated in a folder hook, then the covered settings will be
5646 reverted once the folder is left again.
5647 .Bd -filled -offset indent
5649 Macro behaviour, including option localization, will change in v15.
5650 To be on the absolutely safe side and avoid any surprises it may be wise
5651 to use wrappers that depend on the program version, e.g.,:
5653 .Bd -literal -offset indent
5654 if $version-major < 15
5660 echo "Please re-verify sent-hook (post v15)"
5663 folder-hook-+sent=sent-hook
5667 .It Va folder-hook-FOLDER
5672 Unlike other folder specifications, the fully expanded name of a folder,
5673 without metacharacters, is used to avoid ambiguities.
5674 However, if the mailbox resides under
5678 specification is tried in addition, e.g., if
5682 (and thus relative to the user's home directory) then
5683 .Pa /home/usr1/mail/sent
5685 .Ql folder-hook-/home/usr1/mail/sent
5686 first, but then followed by
5687 .Ql folder-hook-+sent .
5691 \*(BO Controls wether a
5692 .Ql Mail-Followup-To:
5693 header is generated when sending messages to known mailing lists.
5695 .Va followup-to-honour
5697 .Ic mlist , mlsubscribe , reply
5702 .It Va followup-to-honour
5704 .Ql Mail-Followup-To:
5705 header is honoured when group-replying to a message via
5709 This is a quadoption; if set without a value it defaults to
5719 .It Va forward-as-attachment
5720 \*(BO Original messages are normally sent as inline text with the
5723 and only the first part of a multipart message is included.
5724 With this option messages are sent as unmodified MIME
5726 attachments with all of their parts included.
5730 The address (or a list of addresses) to put into the
5732 field of the message header, quoting RFC 5322:
5733 the author(s) of the message, that is, the mailbox(es) of the person(s)
5734 or system(s) responsible for the writing of the message.
5735 If replying to messages these addresses are handled as if they were in
5739 If the machine's hostname is not valid at the Internet (for example at
5740 a dialup machine) then either this variable or
5745 adds even more fine-tuning capabilities),
5749 contains more than one address,
5752 variable is required (according to the standard RFC 5322).
5756 \*(BO When replying to or forwarding a message \*(UA normally removes
5757 the comment and name parts of email addresses.
5758 If this variable is set such stripping is not performed,
5759 and comments, names etc. are retained.
5763 The string to put before the text of a message with the
5767 .Va forward-as-attachment
5770 .Dq -------- Original Message --------
5771 if unset; No heading is put if it is set to the empty string.
5775 \*(BO Causes the header summary to be written at startup and after
5776 commands that affect the number of messages or the order of messages in
5777 the current folder; enabled by default.
5778 The command line option
5786 A format string to use for the summary of
5788 similar to the ones used for
5791 Format specifiers in the given string start with a percent character
5793 and may be followed by an optional decimal number indicating the field
5794 width \(em if that is negative, the field is to be left-aligned.
5795 Valid format specifiers are:
5798 .Bl -tag -compact -offset indent -width "_%%_"
5800 A plain percent character.
5803 a space character but for the current message
5805 for which it expands to
5809 a space character but for the current message
5811 for which it expands to
5814 \*(OP The spam score of the message, as has been classified via the
5817 Shows only a replacement character if there is no spam support.
5819 Message attribute character (status flag); the actual content can be
5823 The date when the message was received, or the date found in the
5827 variable is set (optionally to a date display format string).
5829 The indenting level in threaded mode.
5831 The address of the message sender.
5833 The message thread tree structure.
5834 (Note that this format doesn't support a field width.)
5836 The number of lines of the message, if available.
5840 The number of octets (bytes) in the message, if available.
5842 Message subject (if any).
5844 Message subject (if any) in double quotes.
5846 Message recipient flags: is the addressee of the message a known or
5847 subscribed mailing list \(en see
5852 The position in threaded/sorted order.
5856 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
5858 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
5869 .It Va headline-bidi
5870 Bidirectional text requires special treatment when displaying headers,
5871 because numbers (in dates or for file sizes etc.) will not affect the
5872 current text direction, in effect resulting in ugly line layouts when
5873 arabic or other right-to-left text is to be displayed.
5874 On the other hand only a minority of terminals is capable to correctly
5875 handle direction changes, so that user interaction is necessary for
5877 Note that extended host system support is required nonetheless, e.g.,
5878 detection of the terminal character set is one precondition;
5879 and this feature only works in an Unicode (i.e., UTF-8) locale.
5881 In general setting this variable will cause \*(UA to encapsulate text
5882 fields that may occur when displaying
5884 (and some other fields, like dynamic expansions in
5886 with special Unicode control sequences;
5887 it is possible to fine-tune the terminal support level by assigning
5889 no value (or any value other than
5894 will make \*(UA assume that the terminal is capable to properly deal
5895 with Unicode version 6.3, in which case text is embedded in a pair of
5896 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
5898 In addition no space on the line is reserved for these characters.
5900 Weaker support is chosen by using the value
5902 (Unicode 6.3, but reserve the room of two spaces for writing the control
5903 sequences onto the line).
5908 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
5909 again reserves room for two spaces in addition.
5913 \*(OP If a command line editor is available then this can be set to
5914 name the (expandable) path of the location of a permanent history file.
5917 .It Va history-gabby
5918 \*(BO\*(OP Add more entries to the history as is normally done.
5921 .It Va history-gabby-persist
5922 \*(BO\*(OP \*(UA's own MLE will not save the additional
5924 entries in persistent storage unless this variable is set.
5925 On the other hand it will not loose the knowledge of wether a persistent
5926 entry was gabby or not.
5932 \*(OP If a command line editor is available this value restricts the
5933 amount of history entries that are saved into a set and valid
5935 A value of less than 0 disables this feature;
5936 note that loading and incorporation of
5938 upon program startup can also be suppressed by doing this.
5939 An unset or invalid value, or 0, causes a default value to be used.
5940 Dependent on the available command line editor this will also define the
5941 number of history entries in memory;
5942 it is also editor-specific wether runtime updates of this value will be
5947 \*(BO This option is used to hold messages in the system mailbox,
5948 and it is set by default.
5952 Use this string as hostname when expanding local addresses instead of
5953 the value obtained from
5964 transport is not used then it is normally the responsibility of the MTA
5965 to create these fields, \*(IN in conjunction with
5969 also influences the results;
5970 you should produce some test messages with the desired combination of
5979 \*(BO\*(OP Can be used to turn off the automatic conversion of domain
5980 names according to the rules of IDNA (internationalized domain names
5982 Since the IDNA code assumes that domain names are specified with the
5984 character set, an UTF-8 locale charset is required to represent all
5985 possible international domain names (before conversion, that is).
5989 \*(BO Ignore interrupt signals from the terminal while entering
5990 messages; instead echo them as
5992 characters and discard the current line.
5996 \*(BO Ignore end-of-file conditions
5997 .Pf ( Ql control-D )
5998 in compose mode on message input and in interactive command input.
5999 If set an interactive command input session can only be left by
6000 explicitly using one of the commands
6004 and message input in compose mode can only be terminated by entering
6007 on a line by itself or by using the
6009 .Sx "TILDE ESCAPES" ;
6011 overrides a setting of
6015 .It Va imap-auth-USER@HOST , imap-auth
6016 \*(OP\*(OB Sets the IMAP authentication method.
6017 Valid values are `login' for the usual password-based authentication
6019 `cram-md5', which is a password-based authentication that does not send
6020 the password over the network in clear text,
6021 and `gssapi' for GSS-API based authentication.
6025 \*(OP\*(OB Enables caching of IMAP mailboxes.
6026 The value of this variable must point to a directory that is either
6027 existent or can be created by \*(UA.
6028 All contents of the cache can be deleted by \*(UA at any time;
6029 it is not safe to make assumptions about them.
6031 .Mx Va imap-keepalive
6032 .It Va imap-keepalive-USER@HOST , imap-keepalive-HOST , imap-keepalive
6033 \*(OP\*(OB IMAP servers may close the connection after a period of
6034 inactivity; the standard requires this to be at least 30 minutes,
6035 but practical experience may vary.
6036 Setting this variable to a numeric `value' greater than 0 causes
6037 a `NOOP' command to be sent each `value' seconds if no other operation
6041 .It Va imap-list-depth
6042 \*(OP\*(OB When retrieving the list of folders on an IMAP server, the
6044 command stops after it has reached a certain depth to avoid possible
6046 The value of this variable sets the maximum depth allowed.
6048 If the folder separator on the current IMAP server is a slash `/',
6049 this variable has no effect and the
6051 command does not descend to subfolders.
6053 .Mx Va imap-use-starttls
6054 .It Va imap-use-starttls-USER@HOST , imap-use-starttls-HOST , imap-use-starttls
6055 \*(OP\*(OB Causes \*(UA to issue a `STARTTLS' command to make an unencrypted
6056 IMAP session SSL/TLS encrypted.
6057 This functionality is not supported by all servers,
6058 and is not used if the session is already encrypted by the IMAPS method.
6069 option for indenting messages,
6070 in place of the normal tabulator character
6072 which is the default.
6073 Be sure to quote the value if it contains spaces or tabs.
6077 \*(BO If set, an empty mailbox file is not removed.
6078 This may improve the interoperability with other mail user agents
6079 when using a common folder directory, and prevents malicious users
6080 from creating fake mailboxes in a world-writable spool directory.
6081 Note this only applies to local regular (MBOX) files, other mailbox
6082 types will never be removed.
6085 .It Va keep-content-length
6086 \*(BO When (editing messages and) writing
6088 mailbox files \*(UA can be told to keep the
6092 header fields that some MUAs generate by setting this variable.
6093 Since \*(UA does neither use nor update these non-standardized header
6094 fields (which in itself shows one of their conceptual problems),
6095 stripping them should increase interoperability in between MUAs that
6096 work with with same mailbox files.
6097 Note that, if this is not set but
6098 .Va writebackedited ,
6099 as below, is, a possibly performed automatic stripping of these header
6100 fields already marks the message as being modified.
6104 \*(BO When a message is saved it is usually discarded from the
6105 originating folder when \*(UA is quit.
6106 Setting this option causes all saved message to be retained.
6109 .It Va line-editor-cursor-right
6110 \*(OP If the builtin command line editor is used, actions which are
6111 based on rightwise movement may not work on some terminals.
6112 If you encounter such problems, set this variable to the terminal
6113 control sequence that is necessary to move the cursor one column to the
6117 which should work for most terminals.
6124 and other control character have to be written as shell-style escape
6131 .It Va line-editor-disable
6132 \*(BO Turn off any enhanced line editing capabilities (see
6133 .Sx "Command line editor"
6138 \*(BO When a message is replied to and this variable is set,
6139 it is marked as having been answered.
6140 This mark has no technical meaning in the mail system;
6141 it just causes messages to be marked in the header summary,
6142 and makes them specially addressable.
6146 \*(BO \*(UA generates and expects fully RFC 4155 compliant MBOX text
6148 Messages which are fetched over the network or from within already
6149 existing Maildir (or any non-MBOX) mailboxes may require so-called
6151 quoting (insertion of additional
6153 characters to prevent line content misinterpretation) to be applied in
6154 order to be storable in MBOX mailboxes, however, dependent on the
6155 circumspection of the message producer.
6156 (E.g., \*(UA itself will, when newly generating messages, choose a
6157 .Pf Content-Transfer- Va encoding
6158 that prevents the necessity for such quoting \(en a necessary
6159 precondition to ensure message checksums won't change.)
6161 By default \*(UA will perform this
6163 quoting in a way that results in a MBOX file that is compatible with
6164 the POSIX MBOX layout, which means that, in order not to exceed the
6165 capabilities of simple applications, many more
6167 lines get quoted (thus modified) than necessary according to RFC 4155.
6168 Set this option to instead generate MBOX files which comply to RFC 4155.
6172 \*(BO Internal development variable.
6175 .It Va message-id-disable
6176 \*(BO By setting this option the generation of
6178 can be completely suppressed, effectively leaving this task up to the
6179 mail-transfer-agent (MTA) or the SMTP server.
6180 (According to RFC 5321 your SMTP server is not required to add this
6181 field by itself, so you should ensure that it accepts messages without a
6185 .It Va message-inject-head
6186 A string to put at the beginning of each new message.
6187 The escape sequences tabulator
6194 .It Va message-inject-tail
6195 A string to put at the end of each new message.
6196 The escape sequences tabulator
6204 \*(BO Usually, when an
6206 expansion contains the sender, the sender is removed from the expansion.
6207 Setting this option suppresses these removals.
6212 option to be passed to mail-transfer-agents (MTAs);
6213 though most of the modern MTAs don't (no longer) document this flag, no
6214 MTA is known which doesn't support it (for historical compatibility).
6217 .It Va mime-allow-text-controls
6218 \*(BO When sending messages, each part of the message is MIME-inspected
6219 in order to classify the
6222 .Ql Content-Transfer-Encoding:
6225 that is required to send this part over mail transport, i.e.,
6226 a computation rather similar to what the
6228 command produces when used with the
6232 This classification however treats text files which are encoded in
6233 UTF-16 (seen for HTML files) and similar character sets as binary
6234 octet-streams, forcefully changing any
6239 .Ql application/octet-stream :
6240 If that actually happens a yet unset charset MIME parameter is set to
6242 effectively making it impossible for the receiving MUA to automatically
6243 interpret the contents of the part.
6245 If this option is set, and the data was unambiguously identified as text
6246 data at first glance (by a
6250 file extension), then the original
6252 will not be overwritten.
6255 .It Va mime-alternative-favour-rich
6256 \*(BO If this variable is set then rich MIME alternative parts (e.g.,
6257 HTML) will be preferred in favour of included plain text versions when
6258 displaying messages, provided that a handler exists which produces
6259 output that can be (re)integrated into \*(UA's normal visual display.
6260 (E.g., at the time of this writing some newsletters ship their full
6261 content only in the rich HTML part, whereas the plain text part only
6262 contains topic subjects.)
6265 .It Va mime-counter-evidence
6268 field is used to decide how to handle MIME parts.
6269 Some MUAs however don't use
6271 or a similar mechanism to correctly classify content, but simply specify
6272 .Ql application/octet-stream ,
6273 even for plain text attachments like
6275 If this variable is set then \*(UA will try to classify such MIME
6276 message parts on its own, if possible, for example via a possibly
6277 existent attachment filename.
6278 A non-empty value may also be given, in which case a number is expected,
6279 actually a carrier of bits.
6280 Creating the bit-carrying number is a simple addition:
6281 .Bd -literal -offset indent
6282 ? !echo Value should be set to $((2 + 4 + 8))
6283 Value should be set to 14
6286 .Bl -bullet -compact
6288 If bit two is set (2) then the detected
6290 content-type will be carried along with the message and be used for
6292 .Va pipe-TYPE/SUBTYPE
6293 is responsible for the MIME part, shall that question arise;
6294 when displaying such a MIME part the part-info will indicate the
6295 overridden content-type by showing a plus-sign
6298 If bit three is set (4) then the counter-evidence is always produced
6299 and a positive result will be used as the MIME type, even forcefully
6300 overriding the parts given MIME type.
6302 If bit four is set (8) then as a last resort the actual content of
6303 .Ql application/octet-stream
6304 parts will be inspected, so that data which looks like plain text can be
6309 .It Va mimetypes-load-control
6310 This option can be used to control which of the
6312 databases are loaded by \*(UA, as furtherly described in the section
6313 .Sx "The mime.types files" .
6316 is part of the option value, then the user's personal
6318 file will be loaded (if it exists); likewise the letter
6320 controls loading of the system wide
6321 .Pa /etc/mime.types ;
6322 directives found in the user file take precedence, letter matching is
6324 If this option is not set \*(UA will try to load both files.
6325 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6326 but they will be matched last.
6328 More sources can be specified by using a different syntax: if the
6329 value string contains an equals sign
6331 then it is instead parsed as a comma-separated list of the described
6334 pairs; the given filenames will be expanded and loaded, and their
6335 content may use the extended syntax that is described in the section
6336 .Sx "The mime.types files" .
6337 Directives found in such files always take precedence (are prepended to
6338 the MIME type cache).
6341 .It Va NAIL_EXTRA_RC
6342 The name of an optional startup file to be read after
6344 This variable has an effect only if it is set in
6348 it is not imported from the environment in order to honour
6349 .Ql MAILRC=/dev/null Ns /
6352 Use this file for commands that are not understood by other POSIX
6357 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
6358 \*(BO\*(IN\*(OP Used to control usage of the users
6360 file for lookup of account credentials, as documented in the section
6361 .Sx "On URL syntax and credential lookup"
6365 .Sx "The .netrc file"
6366 documents the file format.
6370 If this variable has the value
6372 newly created local folders will be in Maildir format.
6376 Checks for new mail in the current folder each time the prompt is shown.
6377 For IMAP mailboxes the server is then polled for new mail,
6378 which may result in delayed operation if the connection to the server is
6380 A Maildir folder must be re-scanned to determine if new mail has arrived.
6382 If this variable is set to the special value
6384 an IMAP server is not actively asked for new mail, but new mail may
6385 still be detected and announced with any other IMAP command that is sent
6387 In either case the IMAP server may send notifications about messages
6388 that have been deleted on the server by another process or client.
6390 .Dq Expunged X messages
6391 is printed regardless of this variable, and message numbers may have
6394 If this variable is set to the special value
6396 then a Maildir folder will not be rescanned completely, but only
6397 timestamp changes are detected.
6401 \*(BO Causes the filename given in the
6404 and the sender-based filenames for the
6408 commands to be interpreted relative to the directory given in the
6410 variable rather than to the current directory,
6411 unless it is set to an absolute pathname.
6415 \*(BO If set, each message feed through the command given for
6417 is followed by a formfeed character
6421 .It Va password-USER@HOST , password-HOST , password
6422 \*(IN Variable chain that sets a password, which is used in case none has
6423 been given in the protocol and account-specific URL;
6424 as a last resort \*(UA will ask for a password on the user's terminal if
6425 the authentication method requires a password.
6426 Specifying passwords in a startup file is generally a security risk;
6427 the file should be readable by the invoking user only.
6429 .It Va password-USER@HOST
6430 \*(OU (see the chain above for \*(IN)
6431 Set the password for
6435 If no such variable is defined for a host,
6436 the user will be asked for a password on standard input.
6437 Specifying passwords in a startup file is generally a security risk;
6438 the file should be readable by the invoking user only.
6442 \*(BO Send messages to the
6444 command without performing MIME and character set conversions.
6448 .It Va pipe-TYPE/SUBTYPE
6449 When a MIME message part of type
6451 (case-insensitive) is displayed or quoted,
6452 its text is filtered through the value of this variable interpreted as
6456 forces interpretation of the message part as plain text, e.g.,
6457 .Ql set pipe-application/xml=@
6458 will henceforth display XML
6460 (The same could also be achieved by adding a MIME type marker with the
6463 And \*(OPally MIME type handlers may be defined via
6464 .Sx "The Mailcap files"
6465 \(em corresponding flag strings are shown in parenthesis below.)
6470 can in fact be used to adjust usage and behaviour of a following shell
6471 command specification by appending trigger characters to it, e.g., the
6472 following hypothetical command specification could be used:
6473 .Bd -literal -offset indent
6474 set pipe-X/Y="@*!++=@vim ${NAIL_FILENAME_TEMPORARY}"
6478 .Bl -tag -compact -width ".It Ql __"
6480 Simply by using the special
6482 prefix the MIME type (shell command) handler will only be invoked to
6483 display or convert the MIME part if the message is addressed directly
6484 and alone by itself.
6485 Use this trigger to disable this and always invoke the handler
6486 .Pf ( Cd x-mailx-always ) .
6489 If set the handler will not be invoked when a message is to be quoted,
6490 but only when it will be displayed
6491 .Pf ( Cd x-mailx-noquote ) .
6494 The command will be run asynchronously, i.e., without blocking \*(UA,
6495 which may be a handy way to display a, e.g., PDF file while also
6496 continuing to read the mail message
6497 .Pf ( Cd x-mailx-async ) .
6498 Asynchronous execution implies
6502 The command must be run on an interactive terminal, \*(UA will
6503 temporarily release the terminal to it
6504 .Pf ( Cd needsterminal ) .
6505 This flag is mutual exclusive with
6507 will only be used in interactive mode and implies
6511 Request creation of a zero-sized temporary file, the absolute pathname
6512 of which will be made accessable via the environment variable
6513 .Ev NAIL_FILENAME_TEMPORARY
6514 .Pf ( Cd x-mailx-tmpfile ) .
6515 If this trigger is given twice then the file will be unlinked
6516 automatically by \*(UA when the command loop is entered again at latest
6517 .Pf ( Cd x-mailx-tmpfile-unlink ) .
6518 (Don't use this for asynchronous handlers.)
6521 Normally the MIME part content is passed to the handler via standard
6522 input; if this flag is set then the data will instead be written into
6523 .Ev NAIL_FILENAME_TEMPORARY
6524 .Pf ( Cd x-mailx-tmpfile-fill ) ,
6525 the creation of which is implied; note however that in order to cause
6526 deletion of the temporary file you still have to use two plus signs
6531 To avoid ambiguities with normal shell command content you can use
6532 another at-sign to forcefully terminate interpretation of remaining
6534 (Any character not in this list will have the same effect.)
6538 Some information about the MIME part to be displayed is embedded into
6539 the environment of the shell command:
6542 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6545 The MIME content-type of the part, if known, the empty string otherwise.
6548 .It Ev NAIL_CONTENT_EVIDENCE
6550 .Va mime-counter-evidence
6551 includes the carry-around-bit (2), then this will be set to the detected
6552 MIME content-type; not only then identical to
6553 .Ev \&\&NAIL_CONTENT
6557 .It Ev NAIL_FILENAME
6558 The filename, if any is set, the empty string otherwise.
6561 .It Ev NAIL_FILENAME_GENERATED
6565 .It Ev NAIL_FILENAME_TEMPORARY
6566 If temporary file creation has been requested through the command prefix
6567 this variable will be set and contain the absolute pathname of the
6572 The temporary directory that \*(UA uses.
6573 Usually identical to
6575 but guaranteed to be set and usable by child processes;
6576 to ensure the latter condition for
6583 .It Va pipe-EXTENSION
6584 This is identical to
6585 .Va pipe-TYPE/SUBTYPE
6588 (normalized to lowercase using character mappings of the ASCII charset)
6589 names a file extension, e.g.,
6591 Handlers registered using this method take precedence.
6594 .It Va pop3-auth-USER@HOST , pop3-auth-HOST , pop3-auth
6595 \*(OP\*(IN Variable chain that sets the POP3 authentication method.
6596 The only possible value as of now is
6598 which is thus the default.
6601 .Mx Va pop3-bulk-load
6602 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
6603 \*(BO\*(OP When accessing a POP3 server \*(UA loads the headers of
6604 the messages, and only requests the message bodies on user request.
6605 For the POP3 protocol this means that the message headers will be
6607 If this option is set then \*(UA will download only complete messages
6608 from the given POP3 server(s) instead.
6610 .Mx Va pop3-keepalive
6611 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6612 \*(OP POP3 servers close the connection after a period of inactivity;
6613 the standard requires this to be at least 10 minutes,
6614 but practical experience may vary.
6615 Setting this variable to a numeric value greater than
6619 command to be sent each value seconds if no other operation is performed.
6622 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
6623 \*(BO\*(OP Unless this variable is set the
6625 authentication method will be used when connecting to a POP3 server that
6629 is that the password is not sent in clear text over the wire and that
6630 only a single packet is sent for the user/password tuple.
6632 .Va pop3-no-apop-HOST
6635 .Mx Va pop3-use-starttls
6636 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
6637 \*(BO\*(OP Causes \*(UA to issue a
6639 command to make an unencrypted POP3 session SSL/TLS encrypted.
6640 This functionality is not supported by all servers,
6641 and is not used if the session is already encrypted by the POP3S method.
6643 .Va pop3-use-starttls-HOST
6647 .It Va print-all-chars
6648 \*(BY This option causes all characters to be considered printable.
6649 It is only effective if given in a startup file.
6650 With this option set some character sequences in messages may put the
6651 user's terminal in an undefined state when displayed;
6652 it should only be used as a last resort if no working system locale can
6656 .It Va print-alternatives
6657 \*(BO When a MIME message part of type
6658 .Ql multipart/alternative
6659 is displayed and it contains a subpart of type
6661 other parts are normally discarded.
6662 Setting this variable causes all subparts to be displayed,
6663 just as if the surrounding part was of type
6664 .Ql multipart/mixed .
6668 The string shown when a command is accepted.
6669 Prompting may be prevented by either setting this to the null string
6672 The same XSI escape sequences that are understood by the
6674 command may be used within
6677 In addition, the following \*(UA specific additional sequences are
6684 is set, in which case it expands to
6688 is the default value of
6691 which will expand to
6693 if the last command failed and to
6697 which will expand to the name of the currently active
6699 if any, and to the empty string otherwise, and
6701 which will expand to the name of the currently active mailbox.
6702 (Note that the prompt buffer is size-limited, excess is cut off.)
6708 to encapsulate the expansions of the
6712 escape sequences as necessary to correctly display bidirectional text,
6713 this is not true for the final string that makes up
6715 as such, i.e., real BIDI handling is not supported.
6717 When a newer version of the
6719 .Sx "Command line editor"
6720 is used, any escape sequence must itself be encapsulated with another
6721 escape character for usage with the
6723 mechanism: \*(UA configures the control character
6729 \*(BO Suppresses the printing of the version when first invoked.
6733 If set, \*(UA starts a replying message with the original message
6734 prefixed by the value of the variable
6736 Normally, a heading consisting of
6737 .Dq Fromheaderfield wrote:
6738 is put before the quotation.
6743 variable, this heading is omitted.
6746 is assigned, the headers selected by the
6747 .Ic ignore Ns / Ns Ic retain
6748 commands are put above the message body,
6751 acts like an automatic
6757 is assigned, all headers are put above the message body and all MIME
6758 parts are included, making
6760 act like an automatic
6763 .Va quote-as-attachment .
6766 .It Va quote-as-attachment
6767 \*(BO Add the original message in its entirety as a
6769 MIME attachment when replying to a message.
6770 Note this works regardless of the setting of
6775 \*(OP Can be set in addition to
6777 Setting this turns on a more fancy quotation algorithm in that leading
6778 quotation characters are compressed and overlong lines are folded.
6780 can be set to either one or two (space separated) numeric values,
6781 which are interpreted as the maximum (goal) and the minimum line length,
6782 respectively, in a spirit rather equal to the
6784 program, but line-, not paragraph-based.
6785 If not set explicitly the minimum will reflect the goal algorithmically.
6786 The goal can't be smaller than the length of
6788 plus some additional pad.
6789 Necessary adjustments take place silently.
6792 .It Va recipients-in-cc
6793 \*(BO On group replies, specify only the sender of the original mail in
6795 and mention the other recipients in the secondary
6797 By default all recipients of the original mail will be addressed via
6802 If defined, gives the pathname of the folder used to record all outgoing
6804 If not defined, then outgoing mail is not saved.
6805 When saving to this folder fails the message is not sent,
6806 but instead saved to
6810 .It Va record-resent
6811 \*(BO If both this variable and the
6818 commands save messages to the
6820 folder as it is normally only done for newly composed messages.
6823 .It Va reply-in-same-charset
6824 \*(BO If this variable is set \*(UA first tries to use the same
6825 character set of the original message for replies.
6826 If this fails, the mechanism described in
6827 .Sx "Character sets"
6828 is evaluated as usual.
6831 .It Va reply_strings
6832 Can be set to a comma-separated list of (case-insensitive according to
6833 ASCII rules) strings which shall be recognized in addition to the
6836 reply message indicators \(en builtin are
6838 which is mandated by RFC 5322, as well as the german
6843 A list of addresses to put into the
6845 field of the message header.
6846 Members of this list are handled as if they were in the
6851 .It Va reply-to-honour
6854 header is honoured when replying to a message via
6858 This is a quadoption; if set without a value it defaults to
6862 .It Va rfc822-body-from_
6863 \*(BO This variable can be used to force displaying a so-called
6865 line for messages that are embedded into an envelope mail via the
6867 MIME mechanism, for more visual convenience.
6871 \*(BO Enable saving of (partial) messages in
6873 upon interrupt or delivery error.
6877 When \*(UA initially displays the message headers it determines the
6878 number to display by looking at the speed of the terminal.
6879 The faster the terminal, the more will be shown.
6880 This option specifies the number to use and overrides the calculation.
6881 This number is also used for scrolling with the
6884 Overall screen dimensions and pager usage is influenced by the
6885 environment variables
6893 .It Va searchheaders
6894 \*(BO Expand message-list specifiers in the form
6896 to all messages containing the substring
6900 The string search is case insensitive.
6904 \*(OP A comma-separated list of character set names that can be used in
6905 outgoing internet mail.
6906 The value of the variable
6908 is automatically appended to this list of character-sets.
6909 If no character set conversion capabilities are compiled into \*(UA then
6910 the only supported charset is
6913 .Va sendcharsets-else-ttycharset
6914 and refer to the section
6915 .Sx "Character sets"
6916 for the complete picture of character set conversion in \*(UA.
6919 .It Va sendcharsets-else-ttycharset
6920 \*(BO\*(OP If this variable is set, but
6922 is not, then \*(UA acts as if
6924 had been set to the value of the variable
6926 In effect this combination passes through the message data in the
6927 character set of the current locale (given that
6929 hasn't been set manually), i.e., without converting it to the
6931 fallback character set.
6932 Thus, mail message text will be in ISO-8859-1 encoding when send from
6933 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
6935 If no character set conversion capabilities are available in \*(UA then
6936 the only supported character set is
6941 An address that is put into the
6943 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6944 responsible for the actual transmission of the message.
6945 This field should normally not be used unless the
6947 field contains more than one address, on which case it is required.
6950 address is handled as if it were in the
6956 To use an alternate mail transport agent (MTA),
6957 set this option to the full pathname of the program to use.
6958 It may be necessary to set
6959 .Va sendmail-progname
6962 The MTA will be passed command line arguments from several possible
6963 sources: from the variable
6964 .Va sendmail-arguments
6965 if set, from the command line if given and the variable
6968 Argument processing of the MTA will be terminated with a
6972 The otherwise occurring implicit usage of the following MTA command line
6973 arguments can be disabled by setting the boolean option
6974 .Va sendmail-no-default-arguments
6975 (which will also disable passing
6979 (for not treating a line with only a dot
6981 character as the end of input),
6989 option is set); in conjunction with the
6991 command line option \*(UA will also pass
6997 .It Va sendmail-arguments
6998 Arguments to pass through to the Mail-Transfer-Agent can be given via
7000 The content of this variable will be split up in a vector of arguments
7001 which will be joined onto other possible MTA options:
7003 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
7006 .It Va sendmail-no-default-arguments
7007 \*(BO Unless this option is set \*(UA will pass some well known
7008 standard command line options to the defined
7010 program, see there for more.
7013 .It Va sendmail-progname
7014 Many systems use a so-called
7016 environment to ensure compatibility with
7018 This works by inspecting the name that was used to invoke the mail
7020 If this variable is set then the mailwrapper (the program that is
7021 actually executed when calling
7023 will treat its contents as that name.
7029 \*(BO When sending a message wait until the MTA (including the builtin
7030 SMTP one) exits before accepting further commands.
7032 with this variable set errors reported by the MTA will be recognizable!
7033 If the MTA returns a non-zero exit status,
7034 the exit status of \*(ua will also be non-zero.
7038 \*(BO Setting this option causes \*(UA to start at the last message
7039 instead of the first one when opening a mail folder.
7043 \*(BO Causes \*(UA to use the sender's real name instead of the plain
7044 address in the header field summary and in message specifications.
7048 \*(BO Causes the recipient of the message to be shown in the header
7049 summary if the message was sent by the user.
7053 A string for use with the
7059 A string for use with the
7065 Must correspond to the name of a readable file if set.
7066 The file's content is then appended to each singlepart message
7067 and to the first part of each multipart message.
7068 Be warned that there is no possibility to edit the signature for an
7072 .It Va skipemptybody
7073 \*(BO If an outgoing message does not contain any text in its first or
7074 only message part, do not send it but discard it silently (see also the
7080 \*(OP Specifies a directory with CA certificates in PEM (Privacy
7081 Enhanced Mail) format for verification of S/MIME signed messages.
7084 .It Va smime-ca-file
7085 \*(OP Specifies a file with CA certificates in PEM format for
7086 verification of S/MIME signed messages.
7089 .It Va smime-cipher-USER@HOST , smime-cipher
7090 \*(OP Specifies the cipher to use when generating S/MIME encrypted
7091 messages (for the specified account).
7092 RFC 5751 mandates a default of
7095 Possible values are (case-insensitive and) in decreasing cipher strength:
7103 (DES EDE3 CBC, 168 bits; default if
7105 isn't available) and
7109 The actually available cipher algorithms depend on the cryptographic
7110 library that \*(UA uses.
7111 \*(OP Support for more cipher algorithms may be available through
7112 dynamic loading via, e.g.,
7113 .Xr EVP_get_cipherbyname 3
7114 (OpenSSL) if \*(UA has been compiled to support this.
7117 .It Va smime-crl-dir
7118 \*(OP Specifies a directory that contains files with CRLs in PEM format
7119 to use when verifying S/MIME messages.
7122 .It Va smime-crl-file
7123 \*(OP Specifies a file that contains a CRL in PEM format to use when
7124 verifying S/MIME messages.
7127 .It Va smime-encrypt-USER@HOST
7128 \*(OP If this variable is set, messages send to the given receiver are
7129 encrypted before sending.
7130 The value of the variable must be set to the name of a file that
7131 contains a certificate in PEM format.
7133 If a message is sent to multiple recipients,
7134 each of them for whom a corresponding variable is set will receive an
7135 individually encrypted message;
7136 other recipients will continue to receive the message in plain text
7138 .Va smime-force-encryption
7140 It is recommended to sign encrypted messages, i.e., to also set the
7145 .It Va smime-force-encryption
7146 \*(BO\*(OP Causes \*(UA to refuse sending unencrypted messages.
7149 .It Va smime-no-default-ca
7150 \*(BO\*(OP Don't load default CA locations when verifying S/MIME signed
7155 \*(BO\*(OP S/MIME sign outgoing messages with the user's private key
7156 and include the user's certificate as a MIME attachment.
7157 Signing a message enables a recipient to verify that the sender used
7158 a valid certificate,
7159 that the email addresses in the certificate match those in the message
7160 header and that the message content has not been altered.
7161 It does not change the message text,
7162 and people will be able to read the message as usual.
7164 .Va smime-sign-cert , smime-sign-include-certs
7166 .Va smime-sign-message-digest .
7168 .Mx Va smime-sign-cert
7169 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
7170 \*(OP Points to a file in PEM format.
7171 For the purpose of signing and decryption this file needs to contain the
7172 user's private key as well as his certificate.
7176 is always derived from the value of
7178 (or, if that contains multiple addresses,
7180 For the purpose of encryption the recipient's public encryption key
7181 (certificate) is expected; the command
7183 can be used to save certificates of signed messages (the section
7184 .Sx "Signed and encrypted messages with S/MIME"
7185 gives some details).
7186 This mode of operation is usually driven by the specialized form.
7188 When decrypting messages the account is derived from the recipient
7193 of the message, which are searched for addresses for which such
7195 \*(UA always uses the first address that matches,
7196 so if the same message is sent to more than one of the user's addresses
7197 using different encryption keys, decryption might fail.
7199 .Mx Va smime-sign-include-certs
7200 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
7201 \*(OP If used, this is supposed to a consist of a comma-separated list
7202 of files, each of which containing a single certificate in PEM format to
7203 be included in the S/MIME message in addition to the
7206 This is most useful for long certificate chains if it is desired to aid
7207 the receiving party's verification process.
7208 Note that top level certificates may also be included in the chain but
7209 don't play a role for verification.
7211 .Va smime-sign-cert .
7212 Remember that for this
7214 refers to the variable
7216 (or, if that contains multiple addresses,
7219 .Mx Va smime-sign-message-digest
7220 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7221 \*(OP Specifies the message digest to use when signing S/MIME messages.
7222 RFC 5751 mandates a default of
7224 Possible values are (case-insensitive and) in decreasing cipher strength:
7232 The actually available message digest algorithms depend on the
7233 cryptographic library that \*(UA uses.
7234 \*(OP Support for more message digest algorithms may be available
7235 through dynamic loading via, e.g.,
7236 .Xr EVP_get_digestbyname 3
7237 (OpenSSL) if \*(UA has been compiled to support this.
7238 Remember that for this
7240 refers to the variable
7242 (or, if that contains multiple addresses,
7248 \*(OP Normally \*(UA invokes the program defined via
7250 to transfer messages, as described in
7251 .Sx "On sending mail, and non-interactive mode" .
7254 variable will instead cause SMTP network connections be made to the
7255 server specified therein in order to directly submit the message.
7256 \*(UA knows about three different
7257 .Dq SMTP protocols :
7259 .Bl -bullet -compact
7261 The plain SMTP protocol (RFC 5321) that normally lives on the
7262 server port 25 and requires setting the
7263 .Va smtp-use-starttls
7264 variable to enter a SSL/TLS encrypted session state.
7265 Assign a value like \*(IN
7266 .Ql [smtp://][user[:password]@]server[:port]
7268 .Ql [smtp://]server[:port] )
7269 to choose this protocol.
7271 Then the so-called SMTPS which is supposed to live on server port 465
7272 and is automatically SSL/TLS secured.
7273 Unfortunately it never became a standardized protocol and may thus not
7274 be supported by your hosts network service database
7275 \(en in fact the port number has already been reassigned to other
7278 SMTPS is nonetheless a commonly offered protocol and thus can be
7279 chosen by assigning a value like \*(IN
7280 .Ql smtps://[user[:password]@]server[:port]
7282 .Ql smtps://server[:port] ) ;
7283 due to the mentioned problems it is usually necessary to explicitly
7288 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7289 lives on server port 587 and is practically identically to the SMTP
7290 protocol from \*(UA's point of view beside that; it requires setting the
7291 .Va smtp-use-starttls
7292 variable to enter a SSL/TLS secured session state.
7293 Assign a value like \*(IN
7294 .Ql submission://[user[:password]@]server[:port]
7296 .Ql submission://server[:port] ) .
7299 For more on credentials etc. please see
7300 .Sx "On URL syntax and credential lookup" .
7301 The SMTP transfer is executed in a child process, which runs
7302 asynchronously unless either the
7307 If it receives a TERM signal, it will abort and save the message to
7312 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7313 \*(OP Variable chain that sets the SMTP authentication method.
7320 as well as the \*(OPal methods
7326 method doesn't need any user credentials,
7328 requires a user name and all other methods require a user name and
7336 .Va smtp-auth-password
7338 .Va smtp-auth-user ) .
7343 .Va smtp-auth-USER@HOST :
7344 may override dependend on sender address in the variable
7347 .It Va smtp-auth-password
7348 \*(OP\*(OU Sets the global fallback password for SMTP authentication.
7349 If the authentication method requires a password, but neither
7350 .Va smtp-auth-password
7352 .Va smtp-auth-password-USER@HOST
7354 \*(UA will ask for a password on the user's terminal.
7356 .It Va smtp-auth-password-USER@HOST
7358 .Va smtp-auth-password
7359 for specific values of sender addresses, dependent upon the variable
7362 .It Va smtp-auth-user
7363 \*(OP\*(OU Sets the global fallback user name for SMTP authentication.
7364 If the authentication method requires a user name, but neither
7367 .Va smtp-auth-user-USER@HOST
7369 \*(UA will ask for a user name on the user's terminal.
7371 .It Va smtp-auth-user-USER@HOST
7374 for specific values of sender addresses, dependent upon the variable
7378 .It Va smtp-hostname
7379 \*(IN Normally \*(UA uses the variable
7381 to derive the necessary
7383 information to issue a
7388 can be used to use the
7390 from the SMTP account
7397 from the content of this variable (or, if that is the empty string,
7399 or the local hostname as a last resort).
7400 This often allows using an address that is itself valid but hosted by
7401 a provider other than which (in
7403 is about to send the message.
7404 Setting this variable also influences the generated
7407 .Mx Va smtp-use-starttls
7408 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
7409 \*(BO\*(OP Causes \*(UA to issue a
7411 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
7412 transport layer security.
7416 .It Va spam-interface
7417 \*(OP In order to use any of the spam-related commands (like, e.g.,
7419 the desired spam interface must be defined by setting this variable.
7420 Please refer to the manual section
7422 for the complete picture of spam handling in \*(UA.
7423 All or none of the following interfaces may be available:
7425 .Bl -tag -width ".It Ql _ilte_"
7431 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7433 Different to the generic filter interface \*(UA will automatically add
7434 the correct arguments for a given command and has the necessary
7435 knowledge to parse the program's output.
7438 will have been compiled into the \*(UA binary if
7443 Shall it be necessary to define a specific connection type (rather than
7444 using a configuration file for that), the variable
7446 can be used as in, e.g.,
7447 .Ql -d server.example.com -p 783 .
7448 It is also possible to specify a per-user configuration via
7450 Note that this interface doesn't inspect the
7452 flag of a message for the command
7456 \*(UA will directly communicate with the
7462 stream socket as specified in
7464 It is possible to specify a per-user configuration via
7468 generic spam filter support via freely configurable hooks.
7469 This interface is ment for programs like
7473 and requires according behaviour in respect to the hooks' exit
7474 status for at least the command
7477 meaning a message is spam,
7481 for unsure and any other return value indicating a hard error);
7482 since the hooks can include shell code snippets diverting behaviour
7483 can be intercepted as necessary.
7485 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7488 .Va spamfilter-spam ;
7491 contains examples for some programs.
7492 The process environment of the hooks will have the variables
7493 .Ev NAIL_TMPDIR , TMPDIR
7495 .Ev NAIL_FILENAME_GENERATED
7497 Note that spam score support for
7499 isn't supported unless the \*(OPtional regular expression support is
7501 .Va spamfilter-rate-scanscore
7508 \*(OP Messages that exceed this size won't be passed through to the
7510 .Va spam-interface .
7511 The default is 420000 bytes.
7514 .It Va spamc-command
7515 \*(OP The path to the
7519 .Va spam-interface .
7520 Note that the path is not expanded, but used
7522 A fallback path will have been compiled into the \*(UA binary if the
7523 executable had been found during compilation.
7526 .It Va spamc-arguments
7527 \*(OP Even though \*(UA deals with most arguments for the
7530 automatically, it may at least sometimes be desirable to specifiy
7531 connection-related ones via this variable, e.g.,
7532 .Ql -d server.example.com -p 783 .
7536 \*(OP Specify a username for per-user configuration files for the
7538 .Va spam-interface .
7539 If this is set to the empty string then \*(UA will use the name of the
7545 \*(OP Specify the path of the
7547 domain socket on which
7549 listens for connections for the
7551 .Va spam-interface .
7552 Note that the path is not expanded, but used
7557 \*(OP Specify a username for per-user configuration files for the
7559 .Va spam-interface .
7560 If this is set to the empty string then \*(UA will use the name of the
7569 .It Va spamfilter-ham , spamfilter-noham , \
7570 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7571 \*(OP Command and argument hooks for the
7573 .Va spam-interface .
7576 contains examples for some programs.
7579 .It Va spamfilter-rate-scanscore
7580 \*(OP Because of the generic nature of the
7583 spam scores are not supported for it by default, but if the \*(OPtional
7584 regular expression support is available then setting this variable can
7585 be used to overcome this restriction.
7586 It is interpreted as follows: first a number (digits) is parsed that
7587 must be followed by a semicolon
7589 and an extended regular expression.
7590 Then the latter is used to parse the first output line of the
7592 hook, and, in case the evaluation is successful, the group that has been
7593 specified via the number is interpreted as a floating point scan score.
7597 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7598 Enhanced Mail) for verification of of SSL/TLS server certificates.
7600 .Xr SSL_CTX_load_verify_locations 3
7601 for more information.
7605 \*(OP Specifies a file with CA certificates in PEM format for
7606 verification of SSL/TLS server certificates.
7608 .Xr SSL_CTX_load_verify_locations 3
7609 for more information.
7612 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7613 \*(OP Variable chain that sets the file name for a SSL/TLS client
7614 certificate required by some servers.
7615 This is a direct interface to the
7619 function of the OpenSSL library, if available.
7621 .Mx Va ssl-cipher-list
7622 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7623 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7624 This is a direct interface to the
7628 function of the OpenSSL library, if available; see
7630 for more information.
7631 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7633 specific cipher (protocol standards ship with a list of acceptable
7634 ciphers), possibly cramped to what the actually used SSL/TLS library
7635 supports \(en the manual section
7636 .Sx "An example configuration"
7637 also contains a SSL/TLS use case.
7640 .It Va ssl-config-file
7641 \*(OP If this variable is set \*(UA will call
7642 .Xr CONF_modules_load_file 3
7643 to allow OpenSSL to be configured according to the host system wide
7645 If a non-empty value is given then this will be used to specify the
7646 configuration file to be used instead of the global OpenSSL default;
7647 note that in this case it is an error if the file cannot be loaded.
7648 The application name will always be passed as
7653 \*(OP Specifies a file that contains a CRL in PEM format to use when
7654 verifying SSL/TLS server certificates.
7658 \*(OP Specifies a directory that contains files with CRLs in PEM format
7659 to use when verifying SSL/TLS server certificates.
7662 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7663 \*(OP Variable chain that sets the file name for the private key of
7664 a SSL/TLS client certificate.
7665 If unset, the name of the certificate file is used.
7666 The file is expected to be in PEM format.
7667 This is a direct interface to the
7671 function of the OpenSSL library, if available.
7674 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7676 \*(OB Please use the newer and more flexible
7678 instead: if both values are set,
7680 will take precedence!
7681 Can be set to the following values, the actually used
7683 specification to which it is mapped is shown in parenthesis:
7685 .Pf ( Ql -ALL, TLSv1.2 ) ,
7687 .Pf ( Ql -ALL, TLSv1.1 ) ,
7689 .Pf ( Ql -ALL, TLSv1 )
7692 .Pf ( Ql -ALL, SSLv3 ) ;
7697 and thus includes the SSLv3 protocol.
7698 Note that SSLv2 is no longer supported at all.
7701 .It Va ssl-no-default-ca
7702 \*(BO\*(OP Don't load default CA locations to verify SSL/TLS server
7706 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7707 \*(OP Specify the used SSL/TLS protocol.
7708 This is a direct interface to the
7712 function of the OpenSSL library, if available;
7713 otherwise an \*(UA internal parser is used which understands the
7714 following subset of (case-insensitive) command strings:
7720 as well as the special value
7722 Multiple specifications may be given via a comma-separated list which
7723 ignores any whitespace.
7726 plus prefix will enable a protocol, a
7728 minus prefix will disable it, so that
7730 will enable only the TLSv1.2 protocol.
7732 It depends upon the used TLS/SSL library which protocols are actually
7733 supported and which protocols are used if
7735 is not set, but note that SSLv2 is no longer supported at all and
7737 Especially for older protocols explicitly securing
7739 may be worthwile, see
7740 .Sx "An example configuration" .
7744 \*(OP Gives the pathname to an entropy daemon socket, see
7746 Not all SSL/TLS libraries support this.
7749 .It Va ssl-rand-file
7750 \*(OP Gives the pathname to a file with entropy data, see
7751 .Xr RAND_load_file 3 .
7752 If the file is a regular file writable by the invoking user,
7753 new data is written to it after it has been loaded.
7756 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7757 \*(OP Variable chain that sets the action to be performed if an error
7758 occurs during SSL/TLS server certificate validation.
7759 Valid (case-insensitive) values are
7761 (fail and close connection immediately),
7763 (ask whether to continue on standard input),
7765 (show a warning and continue),
7767 (do not perform validation).
7773 If only set without an assigned value, then this option inhibits the
7778 header fields that include obvious references to \*(UA.
7779 There are two pitfalls associated with this:
7780 First, the message id of outgoing messages is not known anymore.
7781 Second, an expert may still use the remaining information in the header
7782 to track down the originating mail user agent.
7787 suppression doesn't occur.
7791 \*(BY\*(OP If terminal capability queries are supported and this option
7792 is set then \*(UA will try to switch to the
7793 .Dq alternate screen
7794 when in interactive mode, so that the terminal will go back to the
7795 normal screen, leaving all the text there intact, when \*(UA exits.
7798 even when supported for this to produce appealing results the used
7800 and possibly configured
7801 .Va pipe-TYPE/SUBTYPE
7802 applications that take control over the terminal need to have
7803 corresponding support and must be configured accordingly, too, e.g., the
7805 pager should be driven with the
7811 If defined, gives the number of lines of a message to be displayed
7814 normally, the first five lines are printed.
7818 The character set of the terminal \*(UA operates on,
7819 and the one and only supported character set that \*(UA can use if no
7820 character set conversion capabilities have been compiled into it,
7821 in which case it defaults to ISO-8859-1 unless it can deduce a value
7825 Refer to the section
7826 .Sx "Character sets"
7827 for the complete picture about character sets.
7830 .It Va user-HOST , user
7831 \*(IN Variable chain that sets a global fallback user name, which is
7832 used in case none has been given in the protocol and account-specific
7834 This variable defaults to the value of
7839 \*(BO Setting this option enables upward compatibility with \*(UA
7840 version 15.0 in respect to which configuration options are available and
7841 how they are handled.
7842 This manual uses \*(IN and \*(OU to refer to the new and the old way of
7843 doing things, respectively.
7847 \*(BO Setting this option, also controllable via the command line option
7849 causes \*(UA to be more verbose, e.g., it will display obsoletion
7850 warnings and SSL/TLS certificate chains.
7851 Even though marked \*(BO this option may be set twice in order to
7852 increase the level of verbosity even more, in which case even details of
7853 the actual message delivery and protocol conversations are shown.
7856 is sufficient to disable verbosity as such.
7862 .It Va version , version-major , version-minor , version-update
7863 \*(RO \*(UA version information: the first variable contains a string
7864 containing the complete version identification \(en this is identical to
7865 the output of the command
7867 The latter three contain only digits: the major, minor and update
7871 .It Va writebackedited
7872 If this variable is set messages modified using the
7876 commands are written back to the current folder when it is quit;
7877 it is only honoured for writable folders in MBOX format, though.
7878 Note that the editor will be pointed to the raw message content in that
7879 case, i.e., neither MIME decoding nor decryption will have been
7880 performed, and proper RFC 4155
7882 quoting of newly added or edited content is also left as an excercise to
7886 .\" }}} (INTERNAL VARIABLES)
7889 .\" .Sh ENVIRONMENT {{{
7893 .Dq environment variable
7894 should be considered an indication that the following variables are
7895 either standardized as being vivid parts of process environments, or
7896 are commonly found in there.
7897 The process environment is inherited from the
7899 once \*(UA is started, and unless otherwise explicitly noted variables
7900 in there integrate into the normal handling of
7901 .Sx "INTERNAL VARIABLES" ,
7902 from \*(UAs point of view, i.e., they can be
7904 as such in resource files and need not necessarily come from the process
7905 environment and be managed via
7909 E.g., the following example, applicable to a POSIX shell, sets the
7911 environment variable for \*(UA only, and beforehand exports the
7913 in order to affect any further processing in the running shell:
7915 .Bd -literal -offset indent
7916 $ EDITOR="vim -u ${HOME}/.vimrc"
7918 $ COLUMNS=80 \*(ua -R
7921 .Bl -tag -width ".It Ev _AILR_"
7924 The user's preferred width in column positions for the terminal screen
7926 Queried and used once on program startup.
7930 The name of the file to use for saving aborted messages if
7932 is set; this defaults to
7940 Pathname of the text editor to use in the
7944 .Sx "TILDE ESCAPES" .
7945 A default editor is used if this value is not defined.
7949 The user's home directory.
7950 This variable is only used when it resides in the process environment.
7953 to update the value at runtime.
7960 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
7964 .Sx "Character sets" .
7968 The user's preferred number of lines on a page or the vertical screen
7969 or window size in lines.
7970 Queried and used once on program startup.
7974 Pathname of the directory lister to use in the
7976 command when operating on local mailboxes.
7979 (path search through
7984 Is used as the user's mailbox, if set.
7985 Otherwise, a system-dependent default is used.
7986 Supports a logical subset of the special conventions that are documented
7995 \*(OP Overrides the default path search for
7996 .Sx "The Mailcap files" ,
7997 which is defined in the standard RFC 1524 as
7998 .Ql ~/.mailcap:\:/etc/mailcap:\:/usr/etc/mailcap:\:/usr/local/etc/mailcap .
7999 .\" TODO we should have a mailcaps-default virtual RDONLY option!
8000 (\*(UA makes it a configuration option, however.)
8001 Note this is not a search path, but a path search.
8005 Is used as a startup file instead of
8008 When \*(UA scripts are invoked on behalf of other users,
8009 this variable should be set to
8011 to avoid side-effects from reading their configuration files.
8012 This variable is only used when it resides in the process environment.
8016 The name of the user's mbox file.
8017 A logical subset of the special conventions that are documented for the
8022 The fallback default is
8027 Traditionally this secondary mailbox is used as the file to save
8028 messages from the system mailbox that have been read.
8030 .Sx "Message states" .
8033 .It Ev NAIL_NO_SYSTEM_RC
8034 If this variable is set then reading of
8036 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
8037 had been started up with the option
8039 This variable is only used when it resides in the process environment.
8043 \*(IN\*(OP This variable overrides the default location of the user's
8049 The value to put into the
8051 field of the message header.
8055 Pathname of the program to use in the more command or when the
8058 The default paginator is
8060 (path search through
8065 A list of directories that is searched by the shell when looking for
8066 commands (as such only recognized in the process environment).
8070 The shell to use for the commands
8076 and when starting subprocesses.
8077 A default shell is used if this option is not defined.
8081 \*(OP The terminal type for which output is to be prepared.
8085 Used as directory for temporary files instead of
8088 This variable is only used when it resides in the process environment.
8091 to update the value at runtime.
8095 Force identification as the given user, i.e., identical to the
8097 command line option.
8098 This variable is only used when it resides in the process environment.
8101 to update the value at runtime, but note that doing so won't trigger any
8102 of those validation checks that were performed on program startup (again).
8106 Pathname of the text editor to use in the
8110 .Sx "TILDE ESCAPES" .
8118 .Bl -tag -width ".It Pa _etc/mime.type_"
8120 File giving initial commands.
8123 System wide initialization file.
8127 \*(OP Personal MIME type handler definition file, see
8128 .Sx "The Mailcap files" .
8129 (RFC 1524 location, the actual path is a configuration option.)
8133 \*(OP System wide MIME type handler definition file, see
8134 .Sx "The Mailcap files" .
8135 (RFC 1524 location, the actual path is a configuration option.)
8138 .It Pa ~/.mime.types
8139 Personal MIME types, see
8140 .Sx "The mime.types files" .
8143 .It Pa /etc/mime.types
8144 System wide MIME types, see
8145 .Sx "The mime.types files" .
8149 \*(IN\*(OP The default location of the users
8151 file \(en the section
8152 .Sx "The .netrc file"
8153 documents the file format.
8156 .\" .Ss "The mime.types files" {{{
8157 .Ss "The mime.types files"
8159 When sending messages \*(UA tries to determine the content type of all
8161 When displaying message content or attachments \*(UA uses the content
8162 type to decide wether it can directly display data or wether it needs to
8163 deal with content handlers.
8164 It learns about MIME types and how to treat them by reading
8166 files, the loading of which can be controlled by setting the variable
8167 .Va mimetypes-load-control .
8170 can also be used to deal with MIME types.)
8172 files have the following syntax:
8175 .Dl type/subtype extension [extension ...]
8180 are strings describing the file contents, and one or multiple
8182 s, separated by whitespace, name the part of a filename starting after
8183 the last dot (of interest).
8184 Comments may be introduced anywhere on a line with a number sign
8186 causing the remaining line to be discarded.
8188 \*(UA also supports an extended, non-portable syntax in specially
8189 crafted files, which can be loaded via the alternative value syntax of
8190 .Va mimetypes-load-control
8191 and prepends an optional
8195 .Dl [type-marker ]type/subtype extension [extension ...]
8198 The following type markers are supported:
8201 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
8203 Treat message parts with this content as plain text.
8208 Treat message parts with this content as HTML tagsoup.
8209 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
8210 the content as plain text instead.
8214 but instead of falling back to plain text require an explicit content
8215 handler to be defined.
8220 for sending messages:
8222 .Va mime-allow-text-controls ,
8223 .Va mimetypes-load-control .
8224 For reading etc. messages:
8225 .Sx "HTML mail and MIME attachments" ,
8226 .Sx "The Mailcap files" ,
8228 .Va mime-counter-evidence ,
8229 .Va mimetypes-load-control ,
8230 .Va pipe-TYPE/SUBTYPE ,
8231 .Va pipe-EXTENSION .
8234 .\" .Ss "The Mailcap files" {{{
8235 .Ss "The Mailcap files"
8238 .Dq User Agent Configuration Mechanism
8239 which \*(UA \*(OPally supports.
8240 It defines a file format to be used to inform mail user agent programs
8241 about the locally-installed facilities for handling various data
8242 formats, i.e., about commands and how they can be used to display, edit
8243 etc. MIME part contents, as well as a default path search that includes
8244 multiple possible locations of
8248 environment variable that can be used to overwrite that (repeating here
8249 that it is not a search path, but instead a path search specification).
8250 Any existing files will be loaded in sequence, appending any content to
8251 the list of MIME type handler directives.
8255 files consist of a set of newline separated entries.
8256 Comment lines start with a number sign
8258 (in the first column!) and are ignored.
8259 Empty lines are also ignored.
8260 All other lines form individual entries that must adhere to the syntax
8262 To extend a single entry (not comment) its line can be continued on
8263 follow lines if newline characters are
8265 by preceding them with the backslash character
8267 The standard doesn't specify how leading whitespace of follow lines is
8268 to be treated, therefore \*(UA retains it.
8272 entries consist of a number of semicolon
8274 separated fields, and the backslash
8276 character can be used to escape any following character including
8277 semicolon and itself.
8278 The first two fields are mandatory and must occur in the specified
8279 order, the remaining fields are optional and may appear in any order.
8280 Leading and trailing whitespace of content is ignored (removed).
8283 The first field defines the MIME
8285 the entry is about to handle (case-insensitively, and no backslash
8286 escaping is possible in this field).
8287 If the subtype is specified as an asterisk
8289 the entry is ment to match all subtypes of the named type, e.g.,
8291 would match any audio type.
8292 The second field defines the shell command which shall be used to
8294 MIME parts of the given type; it is implicitly called the
8301 shell commands message (MIME part) data is passed via standard input
8302 unless the given shell command includes one or more instances of the
8305 in which case these instances will be replaced with a temporary filename
8306 and the data will have been stored in the file that is being pointed to.
8309 shell commands data is assumed to be generated on standard output unless
8310 the given command includes (one ore multiple)
8312 In any case any given
8314 format is replaced with a(n already) properly quoted filename.
8315 Note that when a command makes use of a temporary file via
8317 then \*(UA will remove it again, as if the
8318 .Cd x-mailx-tmpfile ,
8319 .Cd x-mailx-tmpfile-fill
8321 .Cd x-mailx-tmpfile-unlink
8322 flags had been set; see below for more.
8325 The optional fields either define a shell command or an attribute (flag)
8326 value, the latter being a single word and the former being a keyword
8327 naming the field followed by an equals sign
8329 succeeded by a shell command, and as usual for any
8331 content any whitespace surrounding the equals sign will be removed, too.
8332 Optional fields include the following:
8335 .Bl -tag -width textualnewlines
8337 A program that can be used to compose a new body or body part in the
8344 field, but is to be used when the composing program needs to specify the
8346 header field to be applied to the composed data.
8350 A program that can be used to edit a body or body part in the given
8355 A program that can be used to print a message or body part in the given
8360 Specifies a program to be run to test some condition, e.g., the machine
8361 architecture, or the window system in use, to determine whether or not
8362 this mailcap entry applies.
8363 If the test fails, a subsequent mailcap entry should be sought; also see
8364 .Cd x-mailx-test-once .
8366 .It Cd needsterminal
8367 This flag field indicates that the given shell command must be run on
8368 an interactive terminal.
8369 \*(UA will temporarily release the terminal to the given command in
8370 interactive mode, in non-interactive mode this entry will be entirely
8371 ignored; this flag implies
8372 .Cd x-mailx-noquote .
8374 .It Cd copiousoutput
8375 A flag field which indicates that the output of the
8377 command will be an extended stream of textual output that can be
8378 (re)integrated into \*(UA's normal visual display.
8379 It is mutually exclusive with
8382 .Cd x-mailx-always .
8384 .It Cd textualnewlines
8385 A flag field which indicates that this type of data is line-oriented and
8388 all newlines should be converted to canonical form (CRLF) before
8389 encoding, and will be in that form after decoding.
8393 This field gives a file name format, in which
8395 will be replaced by a random string, the joined combination of which
8396 will be used as the filename denoted by
8397 .Ev NAIL_FILENAME_TEMPORARY .
8398 One could specify that a GIF file being passed to an image viewer should
8399 have a name ending in
8402 .Ql nametemplate=%s.gif .
8403 Note that \*(UA ignores the name template unless that solely specifies
8404 a filename suffix that consists of (ASCII) alphabetic and numeric
8405 characters, the underscore and dot only.
8408 Names a file, in X11 bitmap (xbm) format, which points to an appropriate
8409 icon to be used to visually denote the presence of this kind of data.
8410 This field is not used by \*(UA.
8413 A textual description that describes this type of data.
8415 .It Cd x-mailx-always
8416 Extension flag field that denotes that the given
8418 command shall be executed even if multiple messages will be displayed
8420 Normally messages which require external viewers that produce output
8421 which doesn't integrate into \*(UA's visual display (i.e., don't have
8423 set) have to be addressed directly and individually.
8424 (To avoid cases where, e.g., a thousand PDF viewer instances are spawned
8427 .It Cd x-mailx-even-if-not-interactive
8428 An extension flag test field \(em by default handlers without
8430 are entirely ignored in non-interactive mode, but if this flag is set
8431 then their use will be considered.
8432 It is an error if this flag is set for commands that use the flag
8435 .It Cd x-mailx-noquote
8436 An extension flag field that indicates that even a
8439 command shall not be used to generate message quotes
8440 (as it would be by default).
8442 .It Cd x-mailx-async
8443 Extension flag field that denotes that the given
8445 command shall be executed asynchronously, without blocking \*(UA.
8446 Cannot be used in conjunction with
8449 .It Cd x-mailx-test-once
8450 Extension flag which denotes wether the given
8452 command shall be evaluated once only and the (boolean) result be cached.
8453 This is handy if some global unchanging condition is to be queried, like
8454 .Dq running under the X Window System .
8456 .It Cd x-mailx-tmpfile
8457 Extension flag field that requests creation of a zero-sized temporary
8458 file, the name of which is to be placed in the environment variable
8459 .Ev NAIL_FILENAME_TEMPORARY .
8460 It is an error to use this flag with commands that include a
8464 .It Cd x-mailx-tmpfile-fill
8465 Normally the MIME part content is passed to the handler via standard
8466 input; if this flag is set then the data will instead be written into
8468 .Cd x-mailx-tmpfile .
8469 In order to cause deletion of the temporary file you will have to set
8470 .Cd x-mailx-tmpfile-unlink
8472 It is an error to use this flag with commands that include a
8476 .It Cd x-mailx-tmpfile-unlink
8477 Extension flag field that requests that the temporary file shall be
8478 deleted automatically when the command loop is entered again at latest.
8479 (Don't use this for asynchronous handlers.)
8480 It is an error to use this flag with commands that include a
8482 format, or without also setting
8485 .Cd x-mailx-tmpfile-fill .
8487 .It Cd x-mailx-tmpfile-keep
8490 implies the three tmpfile related flags above, but if you want, e.g.,
8492 and deal with the temporary file yourself, you can add in this flag to
8494 .Cd x-mailx-tmpfile-unlink .
8499 The standard includes the possibility to define any number of additional
8500 entry fields, prefixed by
8502 Flag fields apply to the entire
8504 entry \(em in some unusual cases, this may not be desirable, but
8505 differentiation can be accomplished via separate entries, taking
8506 advantage of the fact that subsequent entries are searched if an earlier
8507 one does not provide enough information.
8510 command needs to specify the
8514 command shall not, the following will help out the latter (with enabled
8518 level \*(UA will show informations about handler evaluation):
8520 .Bd -literal -offset indent
8521 application/postscript; ps-to-terminal %s; needsterminal
8522 application/postscript; ps-to-terminal %s; compose=idraw %s
8526 In fields any occurrence of the format string
8528 will be replaced by the
8531 Named parameters from the
8533 field may be placed in the command execution line using
8535 followed by the parameter name and a closing
8538 The entire parameter should appear as a single command line argument,
8539 regardless of embedded spaces; thus:
8541 .Bd -literal -offset indent
8543 Content-type: multipart/mixed; boundary=42
8546 multipart/*; /usr/local/bin/showmulti \e
8547 %t %{boundary} ; composetyped = /usr/local/bin/makemulti
8549 # Executed shell command
8550 /usr/local/bin/showmulti multipart/mixed 42
8554 .\" TODO v15: Mailcap: %n,%F
8555 Note that \*(UA doesn't support handlers for multipart MIME parts as
8556 shown in this example (as of today).
8557 \*(UA doesn't support the additional formats
8561 An example file, also showing how to properly deal with the expansion of
8563 which includes any quotes that are necessary to make it a valid shell
8564 argument by itself and thus will cause undesired behaviour when placed
8565 in additional user-provided quotes:
8567 .Bd -literal -offset indent
8569 text/richtext; richtext %s; copiousoutput
8571 text/x-perl; perl -cWT %s
8575 trap "rm -f ${infile}" EXIT\e; \e
8576 trap "exit 75" INT QUIT TERM\e; \e
8578 x-mailx-async; x-mailx-tmpfile-keep
8580 application/*; echo "This is \e"%t\e" but \e
8581 is 50 \e% Greek to me" \e; < %s head -c 1024 | cat -vET; \e
8582 copiousoutput; x-mailx-noquote
8587 .Sx "HTML mail and MIME attachments" ,
8588 .Sx "The mime.types files" ,
8591 .Va mime-counter-evidence ,
8592 .Va pipe-TYPE/SUBTYPE ,
8593 .Va pipe-EXTENSION .
8596 .\" .Ss "The .netrc file" {{{
8597 .Ss "The .netrc file"
8601 file contains user credentials for machine accounts.
8602 The default location in the user's
8604 directory may be overridden by the
8606 environment variable.
8607 The file consists of space, tabulator or newline separated tokens.
8608 \*(UA implements a parser that supports a superset of the original BSD
8609 syntax, but users should nonetheless be aware of portability glitches
8610 of that file format, shall their
8612 be usable across multiple programs and platforms:
8615 .Bl -bullet -compact
8617 BSD doesn't support single, but only double quotation marks, e.g.,
8618 .Ql password="pass with spaces" .
8620 BSD (only?) supports escaping of single characters via a backslash
8621 (e.g., a space can be escaped via
8623 in- as well as outside of a quoted string.
8625 BSD doesn't require the final quotation mark of the final user input token.
8627 At least Hewlett-Packard seems to support a format which also allows
8628 tokens to be separated with commas \(en this format is not supported!
8630 Whereas other programs may require that the
8632 file is accessible by only the user if it contains a
8638 \*(UA will always require these strict permissions.
8642 Of the following list of supported tokens \*(UA only uses (and caches)
8647 At runtime the command
8649 can be used to control \*(UAs
8653 .Bl -tag -width password
8654 .It Cd machine Ar name
8655 The hostname of the entries' machine, lowercase-normalized by \*(UA
8657 Any further file content, until either end-of-file or the occurrence
8662 first-class token is bound (only related) to the machine
8665 As an extension that shouldn't be the cause of any worries
8666 \*(UA supports a single wildcard prefix for
8668 .Bd -literal -offset indent
8669 machine *.example.com login USER password PASS
8670 machine pop3.example.com login USER password PASS
8671 machine smtp.example.com login USER password PASS
8677 .Ql pop3.example.com ,
8681 .Ql local.smtp.example.com .
8682 Note that in the example neither
8683 .Ql pop3.example.com
8685 .Ql smtp.example.com
8686 will be matched by the wildcard, since the exact matches take
8687 precedence (it is however faster to specify it the other way around).
8692 except that it is a fallback entry that is used shall none of the
8693 specified machines match; only one default token may be specified,
8694 and it must be the last first-class token.
8696 .It Cd login Ar name
8697 The user name on the remote machine.
8699 .It Cd password Ar string
8700 The user's password on the remote machine.
8702 .It Cd account Ar string
8703 Supply an additional account password.
8704 This is merely for FTP purposes.
8706 .It Cd macdef Ar name
8708 A macro is defined with the specified
8710 it is formed from all lines beginning with the next line and continuing
8711 until a blank line is (consecutive newline characters are) encountered.
8714 entries cannot be utilized by multiple machines, too, but must be
8715 defined following the
8717 they are intended to be used with.)
8720 exists, it is automatically run as the last step of the login process.
8721 This is merely for FTP purposes.
8728 .\" .Sh EXAMPLES {{{
8731 .\" .Ss "An example configuration" {{{
8732 .Ss "An example configuration"
8734 .Bd -literal -offset indent
8735 # This example assumes v15.0 compatibility mode
8738 # Where are the up-to-date SSL certificates?
8739 #set ssl-ca-dir=/etc/ssl/certs
8740 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8742 # (Since we manage up-to-date ones explicitly, don't use any,
8743 # possibly outdated, default certificates shipped with OpenSSL
8744 set ssl-no-default-ca
8746 # Don't use protocols older than TLS v1.2.
8747 # Change this only when the remote server doesn't support it:
8748 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
8749 # such explicit exceptions, then
8750 set ssl-protocol="-ALL,+TLSv1.2"
8752 # Explicitly define the list of ciphers, which may improve security,
8753 # especially with protocols older than TLS v1.2. See ciphers(1).
8754 # Hint: it is important to include "@STRENGTH": only with it the
8755 # final list will be sorted by algorithm strength.
8756 # This is an example: in reality it is possibly best to only use
8757 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
8758 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
8759 !MD5:!RC4:!EXPORT:@STRENGTH"
8761 # Request strict transport security checks!
8762 set ssl-verify=strict
8764 # Essential setting: select allowed character sets
8765 set sendcharsets=utf-8,iso-8859-1
8767 # A very kind option: when replying to a message, first try to
8768 # use the same encoding that the original poster used herself!
8769 set reply-in-same-charset
8771 # When replying to or forwarding a message the comment and name
8772 # parts of email addresses are removed unless this variable is set
8775 # When sending messages, wait until the Mail-Transfer-Agent finishs.
8776 # Only like this you'll be able to see errors reported through the
8777 # exit status of the MTA (including the builtin SMTP one)!
8780 # Only use builtin MIME types, no mime.types(5) files
8781 set mimetypes-load-control
8783 # Default directory where we act in (relative to $HOME)
8785 # A leading "+" (often) means: under *folder*
8786 # *record* is used to save copies of sent messages
8787 set MBOX=+mbox.mbox record=+sent.mbox DEAD=+dead.mbox
8789 # Make "file mymbox" and "file myrec" go to..
8790 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
8792 # Not really optional, e.g., for S/MIME
8793 set from="Your Name <youremail@domain>"
8795 # It may be necessary to set hostname and/or smtp-hostname
8796 # if the "SERVER" of smtp and "domain" of from don't match.
8797 # The `urlencode' command can be used to encode USER and PASS
8798 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
8799 smtp-auth=login/plain... \e
8802 # Never refuse to start into interactive mode, and more
8804 colour-pager crt= \e
8805 followup-to followup-to-honour=ask-yes \e
8806 history-file=+.\*(uahist history-size=-1 history-gabby \e
8807 mime-counter-evidence=0xE \e
8808 prompt="\e033[31m?\e?[\e$ \e@]\e& \e033[0m" \e
8809 reply-to-honour=ask-yes
8811 # When `p'rinting messages, show only these headers
8812 # (use `P'rint for all headers and `S'how for raw message)
8813 retain date from to cc subject
8815 # Some mailing lists
8816 mlist @xyz-editor.xyz$ @xyzf.xyz$
8817 mlsubscribe ^xfans@xfans.xyz$
8819 # A real life example of a very huge free mail provider
8822 set from="Your Name <youremail@domain>"
8823 # (The plain smtp:// proto is optional)
8824 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
8827 # Here is a pretty large one which does not allow sending mails
8828 # if there is a domain name mismatch on the SMTP protocol level,
8829 # which would bite us if the value of from does not match, e.g.,
8830 # for people who have a sXXXXeforge project and want to speak
8831 # with the mailing list under their project account (in from),
8832 # still sending the message through their normal mail provider
8835 set from="Your Name <youremail@domain>"
8836 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
8837 hostname=yaXXex.com smtp-hostname=
8840 # Create some new commands so that, e.g., `ls /tmp' will..
8851 ghost llS !ls -aFlrS
8854 # We don't support gpg(1) directly yet. But simple --clearsign'd
8855 # message parts can be dealt with as follows:
8858 set pipe-text/plain="@*#++=@\e
8859 < \e"${NAIL_FILENAME_TEMPORARY}\e" awk \e
8860 -v TMPFILE=\e"${NAIL_FILENAME_TEMPORARY}\e" '\e
8862 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
8865 print \e"--- GPG --verify ---\e";\e
8866 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
8867 print \e"--- GPG --verify ---\e";\e
8871 /^-----BEGIN PGP SIGNATURE-----/,\e
8872 /^-----END PGP SIGNATURE-----/ {\e
8882 !printf 'Key IDs to gpg --recv-keys: ';\e
8884 gpg --recv-keys ${keyids};
8890 When storing passwords in
8892 appropriate permissions should be set on this file with
8893 .Ql $ chmod 0600 \*(ur .
8896 is available user credentials can be stored in the central
8898 file instead; e.g., here is a different version of the example account
8899 that sets up SMTP and POP3:
8901 .Bd -literal -offset indent
8904 set from="Your Name <youremail@domain>"
8906 #set agent-shell-lookup="gpg -d .pass.gpg"
8908 set smtp=smtps://smtp.yXXXXx.ru:465 \e
8909 smtp-hostname= hostname=yXXXXx.com
8910 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
8911 ghost xp fi pop3s://pop.yXXXXx.ru
8920 .Bd -literal -offset indent
8921 machine *.yXXXXx.ru login USER password PASS
8926 .Va agent-shell-lookup
8927 is available things could be diversified further by using encrypted
8928 password storage: for this, don't specify
8932 file and instead uncomment the line that defines agent lookup in the
8935 above, then create the encrypted password storage file
8938 .Bd -literal -offset indent
8941 $ eval `gpg-agent --daemon \e
8942 --pinentry-program=/usr/bin/pinentry-curses \e
8943 --max-cache-ttl 99999 --default-cache-ttl 99999`
8947 This configuration should now work just fine (use the
8949 command line option for a(n almost) dry-run):
8952 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
8955 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
8956 .Ss "Signed and encrypted messages with S/MIME"
8958 \*(OP S/MIME provides two central mechanisms:
8959 message signing and message encryption.
8960 A signed message contains some data in addition to the regular text.
8961 The data can be used to verify that the message was sent using a valid
8962 certificate, that the sender's address in the message header matches
8963 that in the certificate, and that the message text has not been altered.
8964 Signing a message does not change its regular text;
8965 it can be read regardless of whether the recipient's software is able to
8969 It is thus usually possible to sign all outgoing messages if so desired.
8970 Encryption, in contrast, makes the message text invisible for all people
8971 except those who have access to the secret decryption key.
8972 To encrypt a message, the specific recipient's public encryption key
8974 It is therefore not possible to send encrypted mail to people unless their
8975 key has been retrieved from either previous communication or public key
8977 A message should always be signed before it is encrypted.
8978 Otherwise, it is still possible that the encrypted message text is
8982 A central concept to S/MIME is that of the certification authority (CA).
8983 A CA is a trusted institution that issues certificates.
8984 For each of these certificates it can be verified that it really
8985 originates from the CA, provided that the CA's own certificate is
8987 A set of CA certificates is usually delivered with OpenSSL and installed
8989 If you trust the source of your OpenSSL software installation,
8990 this offers reasonable security for S/MIME on the Internet.
8992 .Va ssl-no-default-ca
8996 .Va smime-ca-dir . )
8997 In general, a certificate cannot be more secure than the method its CA
8998 certificate has been retrieved with, though.
8999 Thus if you download a CA certificate from the Internet,
9000 you can only trust the messages you verify using that certificate as
9001 much as you trust the download process.
9004 The first thing you need for participating in S/MIME message exchange is
9005 your personal certificate, including a private key.
9006 The certificate contains public information, in particular your name and
9007 your email address(es), and the public key that is used by others to
9008 encrypt messages for you,
9009 and to verify signed messages they supposedly received from you.
9010 The certificate is included in each signed message you send.
9011 The private key must be kept secret.
9012 It is used to decrypt messages that were previously encrypted with your
9013 public key, and to sign messages.
9016 For personal use it is recommended that you get a S/MIME certificate
9017 from one of the major CAs on the Internet using your WWW browser.
9018 Many CAs offer such certificates for free.
9020 .Lk https://www.CAcert.org
9021 which issues client and server certificates to members of their
9022 community for free; their root certificate
9023 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
9024 is often not in the default set of trusted CA root certificates, though,
9025 which means you will have to download their root certificate separately
9026 and ensure it is part of our S/MIME certificate validation chain by
9029 or as a vivid member of the
9031 But let's take a step-by-step tour on how to setup S/MIME with
9032 a certificate from CAcert.org despite this situation!
9035 First of all you will have to become a member of the CAcert.org
9036 community, simply by registrating yourself via the web interface.
9037 Once you are, create and verify all email addresses you want to be able
9038 to create signed and encrypted messages for/with using the corresponding
9039 entries of the web interface.
9040 Now ready to create S/MIME certificates, so let's create a new
9041 .Dq client certificate ,
9042 ensure to include all email addresses that should be covered by the
9043 certificate in the following web form, and also to use your name as the
9047 Create a private key and a certificate request on your local computer
9048 (please see the manual pages of the used commands for more in-depth
9049 knowledge on what the used arguments etc. do):
9052 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
9055 Afterwards copy-and-paste the content of
9057 into the certificate-request (CSR) field of the web form on the
9058 CAcert.org website (you may need to unfold some
9059 .Dq advanced options
9060 to see the corresponding text field).
9061 This last step will ensure that your private key (which never left your
9062 box) and the certificate belong together (through the public key that
9063 will find its way into the certificate via the certificate-request).
9064 You are now ready and can create your CAcert certified certificate.
9065 Download and store or copy-and-paste it as
9070 In order to use your new S/MIME setup you will have to create
9071 a combined private key/public key (certificate) file:
9074 .Dl cat key.pem pub.crt > ME@HERE.com.paired
9077 This is the file \*(UA will work with.
9078 If you have created your private key with a passphrase then \*(UA will
9079 ask you for it whenever a message is signed or decrypted.
9080 Set the following variables to henceforth use S/MIME (setting
9082 is of interest for verification only):
9084 .Bd -literal -offset indent
9085 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
9086 smime-sign-cert=ME@HERE.com.paired \e
9087 smime-sign-message-digest=SHA256 \e
9092 From each signed message you send, the recipient can fetch your
9093 certificate and use it to send encrypted mail back to you.
9094 Accordingly if somebody sends you a signed message, you can do the same,
9097 command to check the validity of the certificate.
9100 Variables of interest for S/MIME signing:
9104 .Va smime-crl-file ,
9105 .Va smime-no-default-ca ,
9107 .Va smime-sign-cert ,
9108 .Va smime-sign-include-certs
9110 .Va smime-sign-message-digest .
9113 After it has been verified save the certificate via
9115 and tell \*(UA that it should use it for encryption for further
9116 communication with that somebody:
9118 .Bd -literal -offset indent
9120 set smime-encrypt-USER@HOST=FILENAME \e
9121 smime-cipher-USER@HOST=AES256
9125 Additional variables of interest for S/MIME en- and decryption:
9128 .Va smime-encrypt-USER@HOST .
9131 You should carefully consider if you prefer to store encrypted messages
9133 If you do, anybody who has access to your mail folders can read them,
9134 but if you do not, you might be unable to read them yourself later if
9135 you happen to lose your private key.
9138 command saves messages in decrypted form, while the
9142 commands leave them encrypted.
9145 Note that neither S/MIME signing nor encryption applies to message
9146 subjects or other header fields yet.
9147 Thus they may not contain sensitive information for encrypted messages,
9148 and cannot be trusted even if the message content has been verified.
9149 When sending signed messages,
9150 it is recommended to repeat any important header information in the
9154 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
9155 .Ss "Using CRLs with S/MIME or SSL/TLS"
9157 \*(OP Certification authorities (CAs) issue certificate revocation
9158 lists (CRLs) on a regular basis.
9159 These lists contain the serial numbers of certificates that have been
9160 declared invalid after they have been issued.
9161 Such usually happens because the private key for the certificate has
9163 because the owner of the certificate has left the organization that is
9164 mentioned in the certificate, etc.
9165 To seriously use S/MIME or SSL/TLS verification,
9166 an up-to-date CRL is required for each trusted CA.
9167 There is otherwise no method to distinguish between valid and
9168 invalidated certificates.
9169 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
9170 the Internet, so you have to retrieve them by some external mechanism.
9173 \*(UA accepts CRLs in PEM format only;
9174 CRLs in DER format must be converted, like, e.\|g.:
9177 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
9180 To tell \*(UA about the CRLs, a directory that contains all CRL files
9181 (and no other files) must be created.
9186 variables, respectively, must then be set to point to that directory.
9187 After that, \*(UA requires a CRL to be present for each CA that is used
9188 to verify a certificate.
9191 .\" .Ss "Handling spam" {{{
9194 \*(OP \*(UA can make use of several spam interfaces for the purpose of
9195 identification of, and, in general, dealing with spam messages.
9196 A precondition of most commands in order to function is that the
9198 variable is set to one of the supported interfaces.
9199 Once messages have been identified as spam their (volatile)
9201 state can be prompted: the
9205 message specifications will address respective messages and their
9207 entries will be used when displaying the
9209 in the header display.
9214 rates the given messages and sets their
9217 If the spam interface offers spam scores those can also be displayed in
9218 the header display by including the
9228 will interact with the Bayesian filter of the chosen interface and learn
9229 the given messages as
9233 respectively; the last command can be used to cause
9235 of messages; it adheres to their current
9237 state and thus reverts previous teachings.
9242 will simply set and clear, respectively, the mentioned volatile
9244 message flag, without any interface interaction.
9251 .Va spam-interface Ns s
9255 require a running instance of the
9257 server in order to function, started with the option
9259 shall Bayesian filter learning be possible.
9261 only works via a local path-based
9263 socket, but otherwise the following will be equivalently fine:
9265 .Bd -literal -offset indent
9266 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
9267 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
9268 --daemonize [--local] [--allow-tell]
9272 Thereafter \*(UA can make use of these interfaces:
9274 .Bd -literal -offset indent
9275 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
9276 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
9278 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9279 -Sspamc-command=/usr/local/bin/spamc \e
9280 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
9282 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
9283 -Sspamc-command=/usr/local/bin/spamc \e
9284 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
9288 Using the generic filter approach allows usage of programs like
9292 Here is an example for the former, requiring it to be accessible via
9295 .Bd -literal -offset indent
9296 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
9297 -Sspamfilter-ham="bogofilter -n" \e
9298 -Sspamfilter-noham="bogofilter -N" \e
9299 -Sspamfilter-nospam="bogofilter -S" \e
9300 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
9301 -Sspamfilter-spam="bogofilter -s" \e
9302 -Sspamfilter-rate-scanscore="1;^(.+)$"
9306 Because messages must exist on local storage in order to be scored (or
9307 used for Bayesian filter training), it is possibly a good idea to
9308 perform the local spam check last:
9310 .Bd -literal -offset indent
9311 define spamdelhook {
9313 spamset (header x-dcc-brand-metrics "bulk")
9314 # Server-side spamassassin(1)
9315 spamset (header x-spam-flag "YES")
9316 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
9322 set folder-hook-FOLDER=spamdelhook
9326 See also the documentation for the variables
9327 .Va spam-interface , spam-maxsize ,
9328 .Va spamc-command , spamc-arguments , spamc-user ,
9329 .Va spamd-socket , spamd-user ,
9330 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
9333 .Va spamfilter-rate-scanscore .
9341 .\" .Ss "\*(UA shortly hangs on startup" {{{
9342 .Ss "\*(UA shortly hangs on startup"
9344 This can have two reasons, one is the necessity to wait for a file lock
9345 and can't be helped, the other being that \*(UA calls the function
9347 in order to query the nodename of the box (sometimes the real one is
9348 needed instead of the one represented by the internal variable
9350 You may have varying success by ensuring that the real hostname and
9354 or, more generally, that the name service is properly setup \(en
9357 return what you'd expect?
9358 Does this local hostname has a domain suffix?
9359 RFC 6762 standardized the link-local top-level domain
9363 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
9364 .Ss "I can't login to Google mail a.k.a. GMail"
9366 Since 2014 some free service providers classify programs as
9368 unless they use a special authentification method (OAuth 2.0) which
9369 wasn't standardized for non-HTTP protocol authentication token query
9370 until August 2015 (RFC 7628).
9373 Different to Kerberos / GSSAPI, which is developed since the mid of the
9374 1980s, where a user can easily create a local authentication ticket for
9375 her- and himself with the locally installed
9377 program, that protocol has no such local part but instead requires
9378 a world-wide-web query to create or fetch a token; since there is no
9379 local cache this query has to be performed whenever \*(UA is invoked
9380 from the command line (in interactive sessions situation may differ).
9383 \*(UA doesn't support OAuth.
9384 Because of this it is necessary to declare \*(UA a
9386 (on the providers account web page) in order to read and send mail.
9387 However, it also seems possible to take the following steps instead:
9392 give the provider the number of a mobile phone,
9395 .Dq 2-Step Verification ,
9397 create an application specific password (16 characters), and
9399 use that special password instead of your real Google account password in
9400 S-nail (for more on that see the section
9401 .Sx "On URL syntax and credential lookup" ) .
9407 .\" .Sh "SEE ALSO" {{{
9425 .Xr spamassassin 1 ,
9450 M. Douglas McIlroy writes in his article
9451 .Dq A Research UNIX Reader: Annotated Excerpts \
9452 from the Programmer's Manual, 1971-1986
9455 command already appeared in First Edition
9459 .Bd -ragged -offset indent
9460 Electronic mail was there from the start.
9461 Never satisfied with its exact behavior, everybody touched it at one
9462 time or another: to assure the safety of simultaneous access, to improve
9463 privacy, to survive crashes, to exploit uucp, to screen out foreign
9464 freeloaders, or whatever.
9465 Not until v7 did the interface change (Thompson).
9466 Later, as mail became global in its reach, Dave Presotto took charge and
9467 brought order to communications with a grab-bag of external networks
9473 Mail was written in 1978 by Kurt Shoens and developed as part of the
9476 distribution until 1995.
9477 Mail has then seen further development in open source
9479 variants, noticeably by Christos Zoulas in
9481 Basing upon this Nail, later Heirloom Mailx, was developed by Gunnar
9482 Ritter in the years 2000 until 2008.
9483 Since 2012 S-nail is maintained by Steffen (Daode) Nurpmeso.
9484 This man page is derived from
9485 .Dq The Mail Reference Manual
9486 that was originally written by Kurt Shoens.
9493 .An "Christos Zoulas" ,
9494 .An "Gunnar Ritter" ,
9495 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
9497 .Mt s-mailx@sdaoden.eu ) .
9503 The character set conversion uses and relies upon the
9506 Its functionality differs widely between the various system environments
9510 Limitations with IMAP mailboxes are:
9511 It is not possible to edit messages, but it is possible to append them.
9512 Thus to edit a message, create a local copy of it, edit it, append it,
9513 and delete the original.
9514 The line count for the header display is only appropriate if the entire
9515 message has been downloaded from the server.
9516 The marking of messages as `new' is performed by the IMAP server;
9521 will not cause it to be reset, and if the
9523 variable is unset, messages that arrived during a session will not be
9524 in state `new' anymore when the folder is opened again.
9525 Also if commands queued in disconnected mode are committed,
9526 the IMAP server will delete the `new' flag for all messages in the
9528 and new messages will appear as unread when it is selected for viewing
9530 The `flagged', `answered', and `draft' attributes are usually permanent,
9531 but some IMAP servers are known to drop them without notification.
9532 Message numbers may change with IMAP every time before the prompt is
9533 printed if \*(UA is notified by the server that messages have been
9534 deleted by some other client or process.
9535 In this case, `Expunged n messages' is printed, and message numbers may
9539 Limitations with POP3 mailboxes are:
9540 It is not possible to edit messages, they can only be copied and deleted.
9541 The line count for the header display is only appropriate if the entire
9542 message has been downloaded from the server.
9543 The status field of a message is maintained by the server between
9544 connections; some servers do not update it at all, and with a server
9547 command will not cause the message status to be reset.
9552 variable have no effect.
9553 It is not possible to rename or to remove POP3 mailboxes.
9560 is typed while an IMAP or POP3 operation is in progress, \*(UA will wait
9561 until the operation can be safely aborted, and will then return to the
9562 command loop and print the prompt again.
9565 is typed while \*(UA is waiting for the operation to complete, the
9566 operation itself will be cancelled.
9567 In this case, data that has not been fetched yet will have to be fetched
9568 before the next command can be performed.
9569 If the cancelled operation was using an SSL/TLS encrypted channel,
9570 an error in the SSL transport will very likely result and render the
9571 connection unusable.
9574 As \*(UA is a mail user agent, it provides only basic SMTP services.
9575 If it fails to contact its upstream SMTP server, it will not make
9576 further attempts to transfer the message at a later time,
9577 and it does not leave other information about this condition than an
9578 error message on the terminal and an entry in
9580 This is usually not a problem if the SMTP server is located in the same
9581 local network as the computer on which \*(UA is run.
9582 However, care should be taken when using a remote server of an ISP;
9583 it might be better to set up a local SMTP server then which just acts as
9587 \*(UA immediately contacts the SMTP server (or
9589 ) even when operating in
9592 It would not make much sense for \*(UA to defer outgoing mail since SMTP
9593 servers usually provide much more elaborated delay handling than \*(UA
9594 could perform as a client.
9595 Thus the recommended setup for sending mail in
9597 mode is to configure a local SMTP server such that it sends outgoing
9598 mail as soon as an external network connection is available again,
9599 i.e., to advise it to do that from a network startup script.
9605 With IMAP, at least if the IMAP cache is used, if multiple
9609 cycles happen without an intervening change of the active mailbox then
9610 \*(UA will at some time loose the ability to keep the local state
9611 up-to-date, meaning that, e.g., messages show up with false numbers, and
9612 including the possibility that messages are accessed via numbers that
9613 are no(t longer) valid, resulting in program crashes.
9614 The solution is to change the active mailbox before that happens :).
9617 from the distribution or the repository.
9619 After deleting some message of a POP3 mailbox the header summary falsely
9620 claims that there are no messages to display, you need to perform
9621 a scroll or dot movement to restore proper state.
9623 In threaded display a power user may encounter crashes very
9624 occasionally (this is may and very).