1 .\" Copyright (c) 1980, 1990, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Gunnar Ritter. All rights reserved.
5 .\" Copyright (c) 2012 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
7 .\" Redistribution and use in source and binary forms, with or without
8 .\" modification, are permitted provided that the following conditions
10 .\" 1. Redistributions of source code must retain the above copyright
11 .\" notice, this list of conditions and the following disclaimer.
12 .\" 2. Redistributions in binary form must reproduce the above copyright
13 .\" notice, this list of conditions and the following disclaimer in the
14 .\" documentation and/or other materials provided with the distribution.
15 .\" 3. All advertising materials mentioning features or use of this software
16 .\" must display the following acknowledgement:
17 .\" This product includes software developed by the University of
18 .\" California, Berkeley and its contributors.
19 .\" This product includes software developed by Gunnar Ritter
20 .\" and his contributors.
21 .\" 4. Neither the name of the University nor the names of its contributors
22 .\" may be used to endorse or promote products derived from this software
23 .\" without specific prior written permission.
25 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS 'AS IS' AND
26 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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30 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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33 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 .\"@ S-nail(1): v14.8.12 / 2016-10-05
50 .\" If not ~/.mailrc, it breaks POSIX compatibility. And adjust main.c.
55 .ds OU [no v15-compat]
56 .ds ID [v15 behaviour may differ]
67 .Nd send and receive Internet mail
79 .Op Fl a Ar attachment
82 .Op Fl q Ar quote-file
84 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
89 .Op Fl Fl \: Ar mta-option ...
97 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
100 .Op Fl Fl \: Ar mta-option ...
106 .Op Fl L Ar spec-list
107 .Op Fl r Ar from-addr
108 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
111 .Op Fl Fl \: Ar mta-option ...
116 .Mx -toc -tree html pdf ps xhtml
119 .\" .Sh DESCRIPTION {{{
122 .Bd -filled -compact -offset indent
123 .Sy Compatibility note:
124 S-nail (\*(UA) will wrap up into \%S-mailx in v15.0 (circa 2018).
125 A partial set of compatibility options exist, tagged as \*(IN and \*(OU.
126 To choose upward compatible behaviour, please set the internal variable
128 Anything which will vanish in v15.0 is tagged \*(OB, and using
130 will print warnings for many use cases of obsolete features.
134 \*(UA is a mail processing system with a command syntax reminiscent of
136 with lines replaced by messages.
137 It is intended to provide the functionality of the POSIX
139 command and offers (mostly optional) extensions for line editing, IDNA,
140 MIME, S/MIME, SMTP and POP3 (and IMAP).
141 It is usable as a mail batch language.
143 .\" .Ss "Options" {{{
146 .Bl -tag -width ".Fl _ Ar _ccount"
151 command (see below) for
153 after the startup files have been read.
157 Attach the given file to the message.
158 The same filename conventions as described in the section
160 apply: shell word expansion is restricted to the tilde
165 not be accessible but contain a
167 character, then anything after the
169 is assumed to specify the input character set and anything before
171 the filename: this is the only option to specify the input character set
172 (and don't perform any character set conversion) for text attachments
173 from the command line, not using the
175 tilde escape command.
179 Make standard input and standard output line-buffered.
183 Send blind carbon copies to the given list of addresses.
185 below goes into more detail on that.
189 Send carbon copies to the given list of addresses.
201 variable, which enables debug messages and disables message delivery.
207 variable and thus discard messages with an empty message part body.
208 This is useful for sending messages from scripts.
212 Just check if mail is present in the system mailbox.
213 If yes, return an exit status of zero, a non-zero value otherwise.
217 Save the message to send in a file named after the local part of the
218 first recipient's address (instead of in
223 Read in the contents of the user's
225 (or the specified file) for processing;
226 when \*(UA is quit, it writes undeleted messages back to this file
230 Some special conventions are recognized for the string
232 which are documented for the
237 is not a direct argument to the flag
239 but is instead taken from the command line after option processing has
243 that starts with a hyphen, prefix it with a (relative) path, as in
244 .Ql ./-hyphenbox.mbox .
248 Print a header summary of all messages and exit.
249 A configurable summary view is available via the
255 Print a short usage summary.
256 Because of widespread use a
258 argument will have the same effect.
264 variable to ignore tty interrupt signals.
267 .It Fl L Ar spec-list
268 Print a header summary of only those messages that match the given
272 .Sx "Specifying messages"
277 option has been given in addition no header summary is produced,
278 but \*(UA will instead indicate via its exit status whether
284 note that any verbose output is suppressed in this mode and must instead
285 be enabled explicitly (e.g., by using the option
292 variable and thus inhibit initial display of message headers when
293 reading mail or editing a mail folder.
300 This option should be activated for \*(UA scripts that are invoked on
301 more than one machine, because the contents of that file may differ
303 (The same behaviour can be achieved by setting the
304 .Ev NAIL_NO_SYSTEM_RC
305 environment variable.)
309 Start the message with the contents of the specified file.
310 May be given in send mode only.
314 Any folder opened will be in read-only mode.
320 is a valid address then it specifies the envelope sender address to be
323 when a message is send.
326 include a user name, comments etc., then the components will be
327 separated and the name part will be passed to the MTA individually via
331 will also be assigned to the
333 variable, just as if additionally
335 had been specified (therefore affecting SMTP data transfer, too).
337 If instead an empty string is passed as
339 then the content of the variable
341 will be evaluated and used for this purpose whenever the MTA is
343 Note that \*(UA by default, without
345 that is, neither passes
349 flags to the MTA by itself.
352 .It Fl S Ar variable Ns Op = Ns value
353 Sets the internal option
355 and, in case of a value option, assigns
358 Even though options set via
360 may be overwritten from within resource files,
361 the command line setting will be reestablished after all resource files
366 Specify the subject of the to-be-sent message.
370 The message to be sent is expected to contain a message header with
375 fields giving its recipients, which will be added to those given on the
377 If a message subject is specified via
379 then it'll be used in favour of one given on the command line.
391 Note you can also specify
395 and the envelope address possibly specified with the option
398 The following, which are normally created automatically based
399 upon the message context, can also be specified:
404 .Ql Mail-Followup-To:
405 (special address massage will however still occur for the latter).
409 Read the system mailbox of
411 (appropriate privileges presumed), and
414 in some aspects, e.g. in respect to
423 Print \*(UA's version and exit.
429 option causes some verbosity (like printing of certificate chains).
430 Using it twice increases the level of verbosity.
436 to the list of commands to be executed before normal operation starts.
440 .Va batch-exit-on-error ;
441 the only possibility to execute commands in non-interactive mode when
442 reading startup files is actively prohibited.
448 even if not in interactive mode.
452 This sets several options to prepare \*(UA for working in (most likely
453 non-interactive) batch mode:
465 It also enables processing of
466 .Sx "TILDE ESCAPES" .
467 E.g., the following should send an email message to
469 .Bd -literal -offset indent
470 $ LC_ALL=C printf 'm bob\en~s ubject\enText\en.\enx\en' | \e
471 LC_ALL=C MAILRC=/dev/null s-nail -n -# -Snosave
476 This flag forces termination of option processing in order to prevent
479 It also forcefully puts \*(UA into send mode, see
484 In the above list of supported command line options,
485 .Fl D , d , E , i , N
488 are implemented by means of setting the respective option, as via
491 .Op Ar mta-option ...
493 arguments that are given at the end of the command line after a
495 separator will be passed through to the mail-transfer-agent (MTA) and
496 persist for an entire (interactive) session \(en if the setting of
498 allows their recognition;
499 MTA arguments can also be specified in the variable
500 .Va sendmail-arguments ;
501 find MTA interaction described in more detail in the documentation of
503 MTA arguments are ignored when mail is send via SMTP data transfer.
506 .\" .Ss "A starter" {{{
509 \*(UA is a direct descendant of the BSD Mail program that was introduced
510 in 1978 (itself superceeding the simpler UNIX mail program) and used
511 to introduce itself (in the Mail reference manual) as follows:
513 .Bd -ragged -offset indent
514 Mail provides a simple and friendly environment for sending and
516 It divides incoming mail into its constituent messages and allows the
517 user to deal with them in any order.
518 In addition, it provides a set of
520 -like commands for manipulating messages and sending mail.
521 Mail offers the user simple editing capabilities to ease the composition
522 of outgoing messages, as well as providing the ability to define and
523 send to names which address groups of users.
527 \*(UA is thus the user side of the Unix mail system, whereas the system
528 side (mail-transfer-agent, MTA) was traditionally taken by
534 are often used for this purpose instead.
535 If the \*(OPal SMTP feature has been built into \*(UA then the
536 system side is not a mandatory precondition for mail delivery.
539 Because \*(UA strives for compliance with POSIX
541 it is likely that some configuration settings have to be adjusted before
542 using it is a smooth experience.
545 file already bends those standard settings a bit towards more user
546 friendliness and safety, e.g., it sets the
550 options in order to suppress the automatic moving of messages to
552 that would otherwise occur (see
553 .Sx "Message states" )
556 to not remove empty files in order not to mangle file permissions when
557 files eventually get recreated.
560 option so that by default file grouping (via the
562 prefix as documented also for
567 contains some further suggestions.
570 .\" .Ss "Sending mail" {{{
573 To send a message to one or more people, using a local
574 mail-transfer-agent (MTA; the executable path can be set via
576 or the \*(OPal builtin SMTP (set and see the variable
578 transport to actually deliver the generated mail message, \*(UA can be
579 invoked with arguments which are the names of people to whom the mail
582 .Bd -literal -offset indent
583 $ \*(ua -s Subject -a attachm.ent bill@host1 'Bob <bob@host2>'
584 # But... try it in an isolated dry-run mode first
585 $ LC_ALL=C MAILRC=/dev/null \e
586 \*(ua -n -d -vv -Sfrom="me <he@re>" \e
587 -s Subject -. "(Lovely) Bob <bob@host2>"
591 The user is then expected to type in the message contents.
592 In this compose mode \*(UA treats lines beginning with the character
594 special \(en these are so-called
596 which can be used to read in files, process shell commands, add and edit
597 attachments and more; e.g., the tilde escape
599 will start the text editor to revise the message in it's current state,
601 allows editing of the message recipients and
603 gives an overview of available tilde escapes.
606 at the beginning of an empty line leaves compose mode and causes the
607 message to be send, whereas typing control-C
609 twice will abort the current letter (saving its contents in the file
617 A number of options can be used to alter default behavior; e.g.,
622 will automatically startup a text editor when compose mode is entered,
624 will cause the user to be prompted actively for carbon-copy recipients
627 option will allow leaving compose mode by writing a line consisting
632 Very important, though, is to define which
634 may be used when sending messages, usually by setting the option
637 having read the section
638 .Sx "The mime.types files"
639 to understand how the MIME-type of outgoing attachments is classified
640 and the knowledge that messages are sent asynchronously unless
642 is set: only with it MTA delivery errors will be recognizable.
647 is often necessary (e.g., in conjunction with
649 or desirable, you may want to do some dry-run tests before you go.
650 Saving a copy of the sent messages in a
652 may also be desirable \(en as for most mailbox file targets some
653 special conventions are recognized, see the
655 command for more on that.
657 .Sx "On URL syntax and credential lookup"
658 will spread some light on the
660 variable chains as well as on using URLs for accessing protocol-specific
665 contains an example configuration for sending messages via some of the
666 well-known public mail providers;
667 note it also gives a compact overview on how to setup a secure SSL/TLS
671 Message recipients (as specified on the command line or defined in
676 may not only be email addressees but can also be names of mailboxes and
677 even complete shell command pipe specifications.
678 Proper quoting may be necessary, e.g., to embed whitespace characters.
679 (Recall that \*(UA deals with mail standards, therefore those define the
680 rules with which content is interpreted.)
683 is not set then only network addresses (see
685 for a description of mail addresses) and plain user names (including MTA
686 aliases) may be used, other types will be filtered out, giving a warning
689 .\" When changing any of the following adjust any RECIPIENTADDRSPEC;
690 .\" grep the latter for the complete picture
694 is set then extended recipient addresses will optionally be accepted:
695 Any name which starts with a vertical bar
697 character specifies a command pipe \(en the command string following the
699 is executed and the message is sent to its standard input;
700 Likewise, any name that starts with the character slash
702 or the character sequence dot slash
704 is treated as a file, regardless of the remaining content.
705 Any other name which contains an at sign
707 character is treated as a network address;
708 Any other name which starts with a plus sign
710 character specifies a mailbox name;
711 Any other name which contains a slash
713 character but no exclamation mark
717 character before also specifies a mailbox name;
718 What remains is treated as a network address.
720 .Bd -literal -offset indent
721 $ echo bla | \*(ua -Sexpandaddr -s test ./mbox.mbox
722 $ echo bla | \*(ua -Sexpandaddr -s test '|cat >> ./mbox.mbox'
723 $ echo safe | LC_ALL=C MAILRC=/dev/null \e
724 \*(ua -n -Sv15-compat -Ssendwait -Snosave \e
725 -Sexpandaddr=fail,-all,+addr -s test \e
730 It is possible to create personal distribution lists via the
732 command, so that, for instance, the user can send mail to
734 and have it go to a group of people:
737 .Dl alias cohorts bill jkf mark kridle@ucbcory ~/mail/cohorts.mbox
740 Please note that this mechanism has nothing in common with the system
741 wide aliases that may be used by the local MTA (mail-transfer-agent),
742 which are subject to the
746 and are often tracked in a file
752 Personal aliases will be expanded by \*(UA before the message is sent,
753 and are thus a convenient alternative to specifying each addressee by
757 To avoid environmental noise scripts should
759 \*(ua from any configuration files and create a script-local
760 environment, either by pointing the
762 variable to a custom configuration file, or by using the
764 command line option to specify options:
766 .Bd -literal -offset indent
767 $ env LC_ALL=C MAILRC=/dev/null password=NOTSECRET \e
768 \*(ua -n -Sv15-compat -Ssendwait -Snosave \e
769 -Sexpandaddr=fail,-all,+addr \e
770 -S 'smtp=smtps://mylogin@some.host:465' -Ssmtp-auth=login \e
771 -S 'from=scriptreply@domain' \e
772 -s 'subject' -a attachment_file \e
773 -. "Recipient 1 <recipient1@domain>" recipient2@domain \e
778 .\" .Ss "Reading mail" {{{
781 When invoked without addressees \*(UA enters interactive mode in which
783 When used like that the user's system mailbox
786 for an in-depth description of the different mailbox types that exist)
787 is read in and a one line header of each message therein is displayed.
788 The visual style of this summary of
790 can be adjusted through the variable
792 and the possible sorting criterion via
798 can be performed with the command
800 If the initially opened mailbox is empty \*(UA will instead exit
801 immediately (after displaying a message) unless the variable
810 will give a listing of all available commands and
812 will give a summary of some common ones.
813 If the \*(OPal documentation strings are available one can type
815 and see the actual expansion of
817 and what it's purpose is, i.e., commands can be abbreviated
818 (note that POSIX defines some abbreviations, so that the alphabetical
819 order of commands doesn't necessarily relate to the abbreviations; it is
820 possible to define overwrites with the
825 Messages are given numbers (starting at 1) which uniquely identify
826 messages; the current message \(en the
828 \(en will either be the first new message, or the first unread message,
829 or the first message of the mailbox; the option
831 will instead cause usage of the last message for this purpose.
834 Messages can be printed with the
838 By default the current message
840 is printed, but like with most other commands it is possible to give
841 a fancy message specification (see
842 .Sx "Specifying messages" ) ,
845 will display all unread messages,
850 will print the messages 1 and 5,
852 will print the messages 1 through 5, and
856 will print the last and the next message, respectively.
859 In the default setup all header fields of a message will be printed,
860 but this can be changed: either by blacklisting a list of fields via
862 or by whitelisting only a given list with the
865 .Ql Ic \:retain Ns \0date from to cc subject .
866 In order to print all header fields of a message regardless of currently
867 active ignore or retain lists, use the command
871 controls whether and when \*(UA will use the configured
873 for printing instead of directly writing to the terminal (generally
877 Dependent upon the configuration a
878 .Sx "Command line editor"
879 aims at making user experience with the many
882 When reading the system mailbox or when
886 specified a mailbox explicitly prefixed with the special
888 modifier then messages which have been read will be moved to the user's
890 file automatically when the mailbox is left, either by changing the
891 active mailbox or by quitting \*(UA (also see
892 .Sx "Message states" ) .
895 After examining a message the user can also
899 to the sender and all recipients or
901 exclusively to the sender.
906 Note that when replying to or forwarding a message recipient addresses
907 will be stripped from comments and names unless the option
910 Deletion causes \*(UA to forget about the message;
911 This is not irreversible, though, one can
913 the message by giving its number,
914 or the \*(UA session can be ended by giving the
919 To end a mail processing session one may either issue
921 to cause a full program exit, which possibly includes
922 automatic moving of read messages to
924 as well as updating the \*(OPal command line editor history file,
927 instead in order to prevent any of these actions.
930 .\" .Ss "Viewing HTML mail and MIME attachments" {{{
931 .Ss "Viewing HTML mail and MIME attachments"
933 Messages which are HTML-only get more and more common and of course many
934 messages come bundled with a bouquet of MIME attachments.
935 Whereas \*(UA \*(OPally supports a simple HTML-to-text converter to deal
936 with HTML messages (see
937 .Sx "The mime.types files" ) ,
938 it normally can't deal with any of these itself, but instead programs
939 need to become registered to deal with specific MIME types or file
941 These programs may either prepare plain text versions of their input
942 in order to enable \*(UA to display the content on the terminal,
943 or display the content themselves, for example in a graphical window.
944 The latter type of programs by default
946 \*(UA until the external viewer has terminated, but asynchronous
947 side-by-side execution is also possible, in which case \*(UA will
948 continue to display the message and remain responsive.
951 To install an external handler program for a specific MIME type set an
953 .Va pipe-TYPE/SUBTYPE
955 To define a handler for a specific file extension set the respective
957 variable \(en these handlers take precedence.
959 .Va mime-counter-evidence
960 can be set to improve dealing with faulty MIME part declarations as are
961 often seen in real-life messages.
962 E.g., to display a HTML message inline (that is, converted to a more
963 fancy plain text representation than the builtin converter is capable to
964 produce) with either of the text-mode browsers
968 teach \*(UA about MathML documents and make it display them as plain text
969 and to open PDF attachments in an external PDF viewer, asynchronously:
971 .Bd -literal -offset indent
972 if $features !@ HTML-FILTER
973 #set pipe-text/html="elinks -force-html -dump 1"
974 set pipe-text/html="lynx -stdin -dump -force_html"
975 # Display HTML as plain text instead
976 #set pipe-text/html=@
978 mimetype '@ application/mathml+xml mathml'
979 set pipe-application/pdf="@&set -C;\e
980 : > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e"; \e
981 trap \e"rm -f \e\e\e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e\e\e"\e" \e
982 EXIT INT QUIT PIPE TERM;\e
984 cat > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e"; \e
985 xpdf \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e""
989 Note: special care must be taken when using such commands as mail
990 viruses may be distributed by this method: if messages of type
992 or files with the extension
994 were blindly filtered through the shell, for example, a message sender
995 could easily execute arbitrary code on the system \*(UA is running on.
996 For more on MIME, also in respect to sending of messages, see the
998 .Sx "The mime.types files"
1003 .\" .Ss "Mailing lists" {{{
1006 \*(UA offers some support to ease handling of mailing lists.
1009 promotes all given arguments to known mailing lists, and
1011 sets their subscription attribute, creating them first as necessary.
1016 automatically, but only resets the subscription attribute.)
1017 Using the commands without arguments will print out (a subset of) all
1018 currently defined mailing lists.
1023 can be used to mark out messages with configured list addresses
1024 in the header display.
1027 \*(OPally mailing lists may also be specified as regular expressions,
1028 which allows matching of many addresses with a single expression.
1029 However, all fully qualified list addresses are matched via a fast
1030 dictionary, whereas expressions are placed in (a) list(s) which is
1031 (are) matched sequentially.
1033 .Bd -literal -offset indent
1034 set followup-to followup-to-honour=ask-yes reply-to-honour=ask-yes
1035 mlist a1@b1.c1 a2@b2.c2 .*@lists.c3$
1036 mlsubscribe a4@b4.c4 exact@lists.c3
1041 .Va followup-to-honour
1043 .Ql Mail-\:Followup-\:To:
1044 header is honoured when the message is being replied to (via
1050 controls whether this header is created when sending mails; it will be
1051 created automatically for a couple of reasons, too, like when the
1053 .Dq mailing list specific
1058 is used to respond to a message with its
1059 .Ql Mail-Followup-To:
1063 A difference in between the handling of known and subscribed lists is
1064 that the address of the sender is usually not part of a generated
1065 .Ql Mail-Followup-To:
1066 when addressing the latter, whereas it is for the former kind of lists.
1067 Usually because there are exceptions: say, if multiple lists are
1068 addressed and not all of them are subscribed lists.
1070 For convenience \*(UA will, temporarily, automatically add a list
1071 address that is presented in the
1073 header of a message that is being responded to to the list of known
1075 Shall that header have existed \*(UA will instead, dependend on the
1077 .Va reply-to-honour ,
1080 for this purpose in order to accept a list administrators' wish that
1081 is supposed to have been manifested like that (but only if it provides
1082 a single address which resides on the same domain as what is stated in
1086 .\" .Ss "Resource files" {{{
1087 .Ss "Resource files"
1089 Upon startup \*(UA reads in several resource files:
1091 .Bl -tag -width ".It Pa _AIL_EXTRA_R_"
1094 System wide initialization file.
1095 Reading of this file can be suppressed, either by using the
1097 command line option, or by setting the environment variable
1098 .Ev NAIL_NO_SYSTEM_RC .
1102 File giving initial commands.
1103 A different file can be chosen by setting the environment variable
1106 .It Va NAIL_EXTRA_RC
1107 Can be used to define an optional startup file to be read after
1109 This variable is only honoured in certain circumstances (see its
1110 documentation for more).
1114 The content of these files is interpreted as follows:
1117 .Bl -bullet -compact
1119 A lines' leading whitespace is ignored.
1121 An empty line is ignored.
1123 If the line (content) starts with the number sign
1125 then it is a comment-command \(en a real command! \(en and also ignored.
1126 This command is the only form of comment that is understood.
1130 on the next line if the newline character is
1132 by preceding it with the backslash character
1134 Note that any leading whitespace of follow lines is removed:
1135 If whitespace is desired it must be placed before the backslash.
1138 .Bd -literal -offset indent
1139 # This line is a comment command. And y\e
1140 es, it is really continued here.
1147 .\" .Ss "Character sets" {{{
1148 .Ss "Character sets"
1150 \*(OP \*(UA detects the character set of the terminal by using
1151 mechanisms that are controlled by the
1156 should give an overview); the \*(UA internal variable
1158 will be set to the detected terminal character set accordingly
1159 and will thus show up in the output of the commands
1165 However, a user supplied
1167 value is not overwritten by this detection mechanism: this
1169 must be used if the detection doesn't work properly,
1170 and it may be used to adjust the name of the locale character set.
1171 E.g., on BSD systems one may use a locale with the character set
1172 ISO8859-1, which is not a valid name for this character set; to be on
1173 the safe side, one may set
1175 to the correct name, which is ISO-8859-1.
1178 Note that changing the value doesn't mean much beside that,
1179 since several aspects of the real character set are implied by the
1180 locale environment of the system,
1181 and that stays unaffected by the content of an overwritten
1184 (This is mostly an issue when interactively using \*(UA, though.
1185 It is actually possible to send mail in a completely
1187 locale environment.)
1190 If no character set conversion capabilities have been compiled into
1193 library has been found), then
1195 will be the only supported character set,
1196 it is simply assumed that it can be used to exchange 8-bit messages,
1197 and the rest of this section does not apply;
1198 it may however still be necessary to explicitly set it if automatic
1199 detection fails, since in that case it defaults to the mentioned
1203 When reading messages, their text is converted into
1205 as necessary in order to display them on the users terminal.
1206 Unprintable characters and invalid byte sequences are detected
1207 and replaced by proper substitution characters (unless the variable
1209 was set once \*(UA was started).
1211 .Va charset-unknown-8bit
1212 to deal with another hairy aspect of message interpretation.
1215 When sending messages all their parts and attachments are classified.
1216 Whereas no character set conversion is performed on those parts which
1217 appear to be binary data,
1218 the character set being used must be declared within the MIME header of
1219 an outgoing text part if it contains characters that do not conform to
1220 the set of characters that are allowed by the email standards.
1221 Permissible values for character sets can be declared using the
1225 which defines a catch-all last-resort fallback character set that is
1226 implicitly appended to the list of character-sets in
1230 When replying to a message and the variable
1231 .Va reply-in-same-charset
1232 is set then the character set of the message being replied to is tried
1234 And it is also possible to make \*(UA work even more closely related to
1235 the current locale setting automatically by using the variable
1236 .Va sendcharsets-else-ttycharset ,
1237 please see there for more information.
1240 All the specified character sets are tried in order unless the
1241 conversion of the part or attachment succeeds.
1242 If none of the tried (8-bit) character sets is capable to represent the
1243 content of the part or attachment,
1244 then the message will not be sent and its text will be saved to
1246 In general, if the message
1247 .Dq Cannot convert from a to b
1248 appears, either some characters are not appropriate for the currently
1249 selected (terminal) character set,
1250 or the needed conversion is not supported by the system.
1251 In the first case, it is necessary to set an appropriate
1253 locale and/or the variable
1257 The best results are usually achieved when \*(UA is run in a UTF-8
1258 locale on a UTF-8 capable terminal, in which case the full Unicode
1259 spectrum of characters is available.
1260 In this setup characters from various countries can be displayed,
1261 while it is still possible to use more simple character sets for sending
1262 to retain maximum compatibility with older mail clients.
1265 .\" .Ss "Message states" {{{
1266 .Ss "Message states"
1268 \*(UA differentiates in between several different message states;
1269 the current state will be reflected in the header display if
1271 is configured to do so.
1272 In \*(UA message states are inspected when leaving a mailbox and may
1273 cause messages to be automatically moved to the special
1275 mailbox \(en because this may be irritating to users which are used to
1277 mail-user-agents, the default global
1283 variables in order to suppress this behaviour.
1285 .Bl -tag -width ".It Ql _reserved"
1287 Message has neither been viewed nor moved to any other state.
1288 Such messages are retained even in the system mailbox.
1291 Message has neither been viewed nor moved to any other state, but the
1292 message was present already when the mailbox has been opened last:
1293 Such messages are retained even in the system mailbox.
1296 The message has been processed by one of the following commands:
1316 commands may also cause the next message to be marked as read, depending
1322 command is used, messages that are in the system mailbox or in mailboxes
1323 which were opened with the special
1327 state when the mailbox is left will be saved in
1334 The message has been processed by one of the following commands:
1340 can be used to access such messages.
1343 The message has been processed by a
1345 command and it will be retained in its current location.
1348 The message has been processed by one of the following commands:
1354 command is used, messages that are in the system mailbox or in mailboxes
1355 which were opened with the special
1359 state when the mailbox is left will be deleted; they will be saved in
1367 .\" .Ss "Specifying messages" {{{
1368 .Ss "Specifying messages"
1374 can be given a list of message numbers as arguments to apply to a number
1375 of messages at once.
1378 deletes messages 1 and 2,
1381 will delete the messages 1 through 5.
1382 In sorted or threaded mode (see the
1386 will delete the messages that are located between (and including)
1387 messages 1 through 5 in the sorted/threaded order, as shown in the
1389 Multiple colon modifiers can be joined into one, e.g.,
1391 The following special message names exist:
1393 .Bl -tag -width ".It Ar _n_u"
1399 All old messages (any not in state
1422 All answered messages
1427 All messages marked as draft.
1429 \*(OP All messages classified as spam.
1431 \*(OP All messages with unsure spam classification.
1433 The current message, the so-called
1436 The message that was previously the current message.
1438 The parent message of the current message,
1439 that is the message with the Message-ID given in the
1441 field or the last entry of the
1443 field of the current message.
1445 The next previous undeleted message,
1446 or the next previous deleted message for the
1449 In sorted/threaded mode,
1450 the next previous such message in the sorted/threaded order.
1452 The next undeleted message,
1453 or the next deleted message for the
1456 In sorted/threaded mode,
1457 the next such message in the sorted/threaded order.
1459 The first undeleted message,
1460 or the first deleted message for the
1463 In sorted/threaded mode,
1464 the first such message in the sorted/threaded order.
1467 In sorted/threaded mode,
1468 the last message in the sorted/threaded order.
1472 selects the message addressed with
1476 is any other message specification,
1477 and all messages from the thread that begins at it.
1478 Otherwise it is identical to
1483 the thread beginning with the current message is selected.
1488 All messages that were included in the message list for the previous
1491 .It Ar / Ns Ar string
1492 All messages that contain
1494 in the subject field (case ignored).
1501 the string from the previous specification of that type is used again.
1503 .It Xo Op Ar @ Ns Ar name-list Ns
1506 All messages that contain the given case-insensitive search
1508 ession; if the \*(OPal regular expression (see
1510 support is available
1512 will be interpreted as one if any of the
1514 regular expression characters is seen.
1516 .Ar @ Ns Ar name-list
1517 part is missing, the search is restricted to the subject field body,
1520 specifies a comma-separated list of header fields to search, as in
1522 .Dl '@to,from,cc@Someone i ought to know'
1524 In order to search for a string that includes a
1526 (commercial at) character the
1528 is effectively non-optional, but may be given as the empty string.
1529 Some special header fields may be abbreviated:
1543 respectively and case-insensitively.
1548 can be used to search in (all of) the header(s) of the message, and the
1557 can be used to perform full text searches \(en whereas the former
1558 searches only the body, the latter also searches the message header.
1560 This message specification performs full text comparison, but even with
1561 regular expression support it is almost impossible to write a search
1562 expression that savely matches only a specific address domain.
1563 To request that the content of the header is treated as a list of
1564 addresses, and to strip those down to the plain email address which the
1565 search expression is to be matched against, prefix the header name
1566 (abbreviation) with a tilde
1569 .Dl '@~f@@a\e.safe\e.domain\e.match$'
1573 .Dq any substring matches
1576 header, which will match addresses (too) even if
1578 is set (and POSIX says
1579 .Dq any address as shown in a header summary shall be matchable in this form ) ;
1582 variable is set, only the local part of the address is evaluated
1583 for the comparison, not ignoring case, and the setting of
1585 is completely ignored.
1586 For finer control and match boundaries use the
1588 search expression; the \*(OPal IMAP-style
1590 expression can also be used if substring matches are desired.
1594 \*(OP IMAP-style SEARCH expressions may also be used.
1595 This addressing mode is available with all types of folders;
1596 \*(UA will perform the search locally as necessary.
1597 Strings must be enclosed by double quotes
1599 in their entirety if they contain white space or parentheses;
1600 within the quotes, only backslash
1602 is recognized as an escape character.
1603 All string searches are case-insensitive.
1604 When the description indicates that the
1606 representation of an address field is used,
1607 this means that the search string is checked against both a list
1610 .Bd -literal -offset indent
1611 (\*qname\*q \*qsource\*q \*qlocal-part\*q \*qdomain-part\*q)
1616 and the addresses without real names from the respective header field.
1617 These search expressions can be nested using parentheses, see below for
1621 .Bl -tag -compact -width ".It Ar _n_u"
1622 .It Ar ( criterion )
1623 All messages that satisfy the given
1625 .It Ar ( criterion1 criterion2 ... criterionN )
1626 All messages that satisfy all of the given criteria.
1628 .It Ar ( or criterion1 criterion2 )
1629 All messages that satisfy either
1634 To connect more than two criteria using
1636 specifications have to be nested using additional parentheses,
1638 .Ql (or a (or b c)) ,
1642 .Ql ((a or b) and c) .
1645 operation of independent criteria on the lowest nesting level,
1646 it is possible to achieve similar effects by using three separate
1650 .It Ar ( not criterion )
1651 All messages that do not satisfy
1653 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
1654 All messages that contain
1656 in the envelope representation of the
1659 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
1660 All messages that contain
1662 in the envelope representation of the
1665 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
1666 All messages that contain
1668 in the envelope representation of the
1671 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
1672 All messages that contain
1677 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
1678 All messages that contain
1680 in the envelope representation of the
1683 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
1684 All messages that contain
1689 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
1690 All messages that contain
1693 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
1694 All messages that contain
1696 in their header or body.
1697 .It Ar ( larger size )
1698 All messages that are larger than
1701 .It Ar ( smaller size )
1702 All messages that are smaller than
1706 .It Ar ( before date )
1707 All messages that were received before
1709 which must be in the form
1713 denotes the day of the month as one or two digits,
1715 is the name of the month \(en one of
1716 .Ql Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ,
1719 is the year as four digits, e.g.,
1723 All messages that were received on the specified date.
1724 .It Ar ( since date )
1725 All messages that were received since the specified date.
1726 .It Ar ( sentbefore date )
1727 All messages that were sent on the specified date.
1728 .It Ar ( senton date )
1729 All messages that were sent on the specified date.
1730 .It Ar ( sentsince date )
1731 All messages that were sent since the specified date.
1733 The same criterion as for the previous search.
1734 This specification cannot be used as part of another criterion.
1735 If the previous command line contained more than one independent
1736 criterion then the last of those criteria is used.
1740 .\" .Ss "On URL syntax and credential lookup" {{{
1741 .Ss "On URL syntax and credential lookup"
1743 \*(IN For accessing protocol-specific resources, like POP3 mailboxes,
1744 usage of compact and standardized Uniform Resource Locators
1745 (URL, RFC 1738) has become omnipresent.
1746 \*(UA expects and understands URLs in the following form;
1749 denote optional parts, optional either because there also exist other
1750 ways to define the information in question or because support of the
1751 part is protocol-specific \(en e.g.,
1753 is used by the IMAP protocol but not by POP3.
1756 .Dl PROTOCOL://[USER[:PASSWORD]@]server[:port][/path]
1763 are specified as part of an URL they must be given in URL percent
1764 encoded (RFC 3986) form \(en the command
1766 can be used to perform the encoding and show the encoded value.
1767 (This doesn't really conform to any standard, but for one it isn't
1768 used for any data exchange over the internet, and second it's easier for
1769 users to simply call
1771 on a string and use that instead of having to deal with several
1772 different standards.)
1773 On the other hand, values given in variables are expected not to be URL
1777 Many variable options of \*(UA exist in multiple versions, called
1778 variable chains for the rest of this document: the plain
1783 .Ql variable-USER@HOST .
1790 had been specified in the respective URL, otherwise it refers to the plain
1796 that had been found when doing the user chain lookup as is described
1799 will never be in URL percent encoded form, whether it came from an URL or not.
1802 For example, whether an hypothetical URL
1803 .Ql smtp://hey%3Ayou@our.house
1804 had been given that includes a user, or whether the URL was
1805 .Ql smtp://our.house
1806 and the user had been found differently, to lookup the variable chain
1807 .Va smtp-use-starttls
1808 \*(UA first looks for whether
1809 .Ql smtp-\:use-\:starttls-\:hey:you@our.house
1810 is defined, then whether
1811 .Ql smtp-\:use-\:starttls-\:our.house
1812 exists before finally ending up looking at the plain variable itself.
1815 \*(UA obeys the following logic scheme when dealing with the
1816 necessary credential informations of an account:
1822 has been given in the URL the variables
1826 are looked up; if no such variable(s) can be found then \*(UA will,
1827 when enforced by the \*(OPal variables
1828 .Va netrc-lookup-HOST
1835 specific entry which provides a
1837 name: this lookup will only succeed if unambiguous (one possible matching
1841 If there is still no
1843 then \*(UA will fall back to the user who is supposed to run \*(UA:
1844 either the name that has been given with the
1846 command line option (or, equivalently, but with less precedence, the
1847 environment variable
1852 The identity of this user has been fixated during \*(UA startup and is
1853 known to be a valid user on the current host.
1856 Authentication: unless otherwise noted this will lookup the
1857 .Va PROTOCOL-auth-USER@HOST , PROTOCOL-auth-HOST , PROTOCOL-auth
1858 variable chain, falling back to a protocol-specific default should this
1864 has been given in the URL \(en it should be noted once that specifying
1865 the password in the URL is only syntactic sugar for the user, it'll
1866 never be part of an URL that \*(UA uses itself \(en, then if the
1868 has been found through the \*(OPal
1870 file lookup then that may have already provided the password, too.
1871 Otherwise the variable chain
1872 .Va password-USER@HOST , password-HOST , password
1875 \*(OP Then if any of the variables of the chain
1876 .Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
1878 is set the shell command specified therein is run and the output (less
1879 newline characters) will be used as the password.
1880 It is perfectly valid for such an agent to simply not return any data,
1881 in which case the password lookup is continued somewhere else;
1882 Any command failure is treated as a hard error, however.
1884 The next variable chain that is inspected is the \*(OPal
1885 .Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup ,
1886 but this time looking only for the password (multiple user accounts
1887 for a single machine may exist as well as a fallback entry without
1888 user but with a password).
1890 If at that point there is still no password available, but the
1891 (protocols') chosen authentication type requires a password, then in
1892 interactive mode the user will be prompted on the terminal.
1897 S/MIME verification works relative to the values found in the
1901 header field(s), which means that the values of
1902 .Va smime-sign , smime-sign-cert , smime-sign-include-certs
1904 .Va smime-sign-message-digest
1905 will not be looked up using the
1909 chains from above but instead use the corresponding values from the
1910 message that is being worked on.
1911 In unusual cases multiple and different
1915 combinations may therefore be involved \(en on the other hand those
1916 unusual cases become possible.
1917 The usual case is as short as:
1920 .Dl set smtp=smtp://USER:PASS@HOST smtp-use-starttls \e
1921 .Dl \ \ \ \ smime-sign smime-sign-cert=+smime.pair
1926 contains complete example configurations.
1929 .\" .Ss "Command line editor" {{{
1930 .Ss "Command line editor"
1932 \*(OP \*(UA can be configured to support a command line editor and
1933 command history lists which are saved in between sessions.
1934 One may link against fully-fledged external libraries
1935 .Pf ( Xr readline 6 ,
1937 ) or use \*(UA's own command line editor NCL (Nail-Command-Line)
1938 instead, which should work in all environments which comply to the
1939 ISO C standard (ISO/IEC 9899:1990/Amendment 1:1995).
1940 When an external library is used, interactive behaviour of \*(UA relies
1941 on that library and may not correspond one-to-one to what is described
1945 Regardless of the actually used command line editor
1947 entries will be created for lines entered in command mode only, and
1948 creation of such an entry can be forcefully suppressed by starting the
1949 line with a space character.
1952 handling is by itself an optional feature and may therefore not be
1954 For more information see the documentation of the options
1957 .Va history-gabby-persist ,
1958 .Va line-editor-disable ,
1964 The builtin \*(UA command line editor supports the following operations;
1967 stands for the combination of the
1969 key plus the mentioned character, e.g.,
1972 .Dq hold down control key and press the A key :
1975 .Bl -tag -compact -width "Ql _M"
1977 Go to the start of the line.
1979 Move the cursor backward one character.
1981 Forward delete the character under the cursor;
1982 quits \*(UA if used on the empty line unless the
1986 Go to the end of the line.
1988 Move the cursor forward one character.
1991 Cancel current operation, full reset.
1992 If there is an active history search or tabulator expansion then this
1993 command will first reset that, reverting to the former line content;
1994 thus a second reset is needed for a full reset in this case.
1995 In all cases \*(UA will reset a possibly used multibyte character input
2001 backward delete one character.
2005 .Dq horizontal tabulator :
2006 try to expand the word before the cursor.
2008 .Dq tabulator-completion
2009 as is known from the
2011 but really means the usual \*(UA expansion, as documented for
2013 yet it involves shell expansion as a last step, too.)
2018 complete this line of input.
2020 Delete all characters from the cursor to the end of the line.
2024 \*(OP Go to the next history entry.
2029 \*(OP Go to the previous history entry.
2031 \*(OP Complete the current line from (the remaining older) history entries.
2038 Delete the characters from the one preceding the cursor to the preceding
2041 Move the cursor forward one word boundary.
2043 Move the cursor backward one word boundary.
2047 If problems with commands that are based upon rightwise movement are
2048 encountered, adjustments of the option
2049 .Va line-editor-cursor-right
2050 may solve the problem, as documented for it.
2053 If the terminal produces key sequences which are compatible with
2055 then the left and right cursor keys will map to
2059 respectively, the up and down cursor keys will map to
2063 and the Home/End/PgUp/PgDown keys will call the
2065 command with the respective arguments
2071 (i.e., perform scrolling through the header summary list).
2074 .\" .Ss "Coloured message display" {{{
2075 .Ss "Coloured message display"
2077 \*(OP \*(UA can be configured to support coloured message display,
2078 realized by emitting ANSI colour escape sequences.
2079 Colours are only used when the
2081 environment variable is set and either the terminal type can be found in
2083 or its name includes the string
2087 On top of that the binary option
2089 defines whether these colour sequences are also generated when the output
2090 of a command needs to go through the
2094 ) \(en this is not enabled by default because different pager programs
2095 need different command line switches or other configuration in order to
2096 support those colour sequences, please see the option for more details.
2099 To forcefully disable all colour support, set
2100 .Va colour-disable .
2103 Colours can be configured through font attributes
2124 Multiple specifications can be joined in a comma separated list, as in
2127 .Dl set colour-msginfo="ft=bold,fg=magenta,bg=cyan"
2130 Options to be set are
2131 .Va colour-msginfo ,
2132 .Va colour-partinfo ,
2136 .Va colour-uheader ,
2138 .Va colour-user-headers ,
2139 which is a list of headers to be colourized via
2141 instead of the default
2144 .\" }}} (DESCRIPTION)
2147 .\" .Sh COMMANDS {{{
2150 Each command is typed on a line by itself,
2151 and may take arguments following the command word.
2152 The command need not be typed in its entirety \(en
2153 the first command which matches the typed prefix is used.
2156 prints a sorted list of available commands, and the command
2160 when given an argument, will show a documentation string for the
2163 documentation strings are however \*(OPal.)
2166 For commands which take message lists as arguments, the next message
2167 forward that satisfies the command's requirements will be used shall no
2168 explicit message list have been passed.
2169 If there are no messages forward of the current message,
2170 the search proceeds backwards,
2171 and if there are no good messages at all,
2173 .Dq no applicable messages
2174 and aborts the command.
2175 The arguments to commands can be quoted, using the following methods:
2178 .Bl -bullet -compact -offset indent
2180 An argument can be enclosed between paired double-quotes
2185 any white space, shell word expansion, or backslash characters (except
2186 as described next) within the quotes are treated literally as part of
2188 A double-quote will be treated literally within single-quotes and vice
2190 Inside such a quoted string the actually used quote character can be
2191 used nonetheless by escaping it with a backslash
2197 An argument that is not enclosed in quotes, as above, can usually still
2198 contain space characters if those spaces are backslash-escaped.
2201 A backslash outside of the enclosing quotes is discarded
2202 and the following character is treated literally as part of the argument.
2205 An unquoted backslash at the end of a command line is discarded and the
2206 next line continues the command.
2210 Filenames, where expected, are subsequently subjected to the following
2211 transformations, in sequence:
2214 .Bl -bullet -compact -offset indent
2216 If the filename begins with an unquoted plus sign, and the
2218 variable is defined,
2219 the plus sign will be replaced by the value of the
2221 variable followed by a slash.
2224 variable is unset or is set to null, the filename will be unchanged.
2227 Shell word expansions are applied to the filename.
2228 .\" TODO shell word expansion shell expand fexpand FEXP_NSHELL
2229 .Sy Compatibility note:
2230 on the long run support for complete shell word expansion will be
2231 replaced by an internally implemented restricted expansion mechanism in
2232 order to circumvent possible security impacts through shell expansion.
2233 Expect that a growing number of program parts only support this
2236 Meta expansions are applied to the filename: leading tilde characters
2238 will be replaced by the expansion of
2240 and any occurrence of
2244 will be replaced by the expansion of the variable, if possible;
2245 \*(UA internal as well as environmental (shell) variables can be
2246 accessed through this mechanism.
2247 In order to include a raw
2249 character precede it with a backslash
2251 to include a backslash double it.
2252 If more than a single pathname results from this expansion and the
2253 command is expecting one file, an error results.
2255 Note that in interactive display context, in order to allow simple
2256 value acceptance (typing
2258 backslash quoting is performed automatically as necessary, e.g., a file
2259 .Ql diet\e is \ecurd.txt
2260 will be displayed as
2261 .Ql diet\e\e is \e\ecurd.txt .
2265 The following commands are available:
2267 .Bl -tag -width ".Ic _ccount"
2270 The comment-command causes the entire line to be ignored.
2272 this really is a normal command which' purpose is to discard its
2275 indicating special character, which means that, e.g., trailing comments
2276 on a line are not possible.
2280 Interprets the remainder of the word as a macro name and passes it
2285 is a shorter synonym for
2286 .Ql call Ar mymacro .
2290 Print out the preceding message.
2291 If given a numeric argument n,
2292 goes to the n'th previous message and prints it.
2296 Show the current message number (the
2301 Prints a brief summary of commands.
2302 \*(OP Given an argument a synopsis for the command in question is
2304 commands can be abbreviated in general and this command can be used
2305 to see the full expansion of an abbreviation including the synopsis,
2311 and see how the display changes.
2319 ) command which follows.
2329 (ac) Creates, selects or lists (an) account(s).
2330 An account is a group of commands and variable settings which together
2331 usually arrange the environment for the purpose of creating a system login.
2332 Without any argument a listing of all defined accounts and their content
2334 A specific account can be activated by giving solely its name, resulting
2335 in the system mailbox or inbox of that account to be activated as via an
2336 explicit use of the command
2338 The two argument form is identical to defining a macro as via
2341 .Bd -literal -offset indent
2343 set folder=imaps://mylogin@imap.myisp.example
2345 set from="myname@myisp.example (My Name)"
2346 set smtp=smtp://mylogin@smtp.myisp.example
2350 creates an account named
2352 which can later be selected by specifying
2356 (case-insensitive) always exists.
2358 can be used to localize account settings \(en different to normal macros
2359 the settings will be reverted once the account is switched off.
2360 Accounts can be deleted via
2365 (a) With no arguments, prints out all currently-defined aliases.
2366 With one argument, prints out that alias.
2367 With more than one argument,
2368 creates a new alias or appends to an existing one.
2370 can be used to delete aliases.
2374 (alt) Manage a list of alternate addresses / names of the active user,
2375 members of which will be removed from recipient lists when replying to
2378 variable is not set).
2379 If arguments are given the set of alternate names is replaced by them,
2380 without arguments the current set is displayed.
2384 Takes a message list and marks each message as having been answered.
2385 This mark has no technical meaning in the mail system;
2386 it just causes messages to be marked in the header summary,
2387 and makes them specially addressable.
2391 \*(OP Only applicable to cached IMAP mailboxes;
2392 takes a message list and reads the specified messages into the IMAP
2397 Calls a macro that has been created via
2402 (ch) Change the working directory to
2404 or the given argument.
2410 \*(OP Only applicable to S/MIME signed messages.
2411 Takes a message list and a file name and saves the certificates
2412 contained within the message signatures to the named file in both
2413 human-readable and PEM format.
2414 The certificates can later be used to send encrypted messages to the
2415 respective message senders by setting
2416 .Va smime-encrypt-USER@HOST
2421 (ch) Change the working directory to
2423 or the given argument.
2429 Only applicable to threaded mode.
2430 Takes a message list and makes all replies to these messages invisible
2431 in header summaries, unless they are in state
2436 \*(OP If operating in disconnected mode on an IMAP mailbox,
2437 switch to online mode and connect to the mail server while retaining
2439 See the description of the
2441 variable for more information.
2445 (C) Copy messages to files whose names are derived from the author of
2446 the respective message and don't mark them as being saved;
2447 otherwise identical to
2452 (c) Copy messages to the named file and don't mark them as being saved;
2453 otherwise identical to
2458 Print the current working directory.
2462 \*(OP For unencrypted messages this command is identical to
2464 Encrypted messages are first decrypted, if possible, and then copied.
2468 \*(OP For unencrypted messages this command is identical to
2470 Encrypted messages are first decrypted, if possible, and then copied.
2474 Without arguments the current list of macros, including their content,
2475 is printed, but otherwise a macro is defined.
2476 A macro definition is a sequence of commands in the following form:
2477 .Bd -literal -offset indent
2486 A defined macro can be invoked explicitly by using the
2490 commands, or implicitly by setting the
2493 .Va folder-hook-FOLDER
2495 Note that interpretation of
2497 depends on how (i.e.,
2499 normal macro, folder hook, account switch) the macro is invoked.
2500 Macros can be deleted via
2505 (d) Marks the given message list as
2507 Deleted messages will neither be saved in
2509 nor will they be available for most other commands.
2520 \*(OP (disco) If operating in online mode on an IMAP mailbox,
2521 switch to disconnected mode while retaining the mailbox status.
2522 See the description of the
2525 A list of messages may optionally be given as argument;
2526 the respective messages are then read into the cache before the
2527 connection is closed.
2528 Thus `disco *' makes the entire mailbox available for disconnected use.
2533 Deletes the current message and prints the next message.
2534 If there is no next message, \*(UA says
2539 Takes a message list and marks each given message as a draft.
2540 This mark has no technical meaning in the mail system;
2541 it just causes messages to be marked in the header summary,
2542 and makes them specially addressable.
2546 (ec) Echoes its arguments,
2547 resolving special names as documented for the command
2549 The escape sequences
2561 are interpreted just as they are by
2563 (proper quoting provided).
2567 (e) Point the text editor (as defined in
2569 at each message from the given list in turn.
2570 Modified contents are discarded unless the
2577 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2578 conditional \(em if the condition of a preceeding
2580 was false, check the following condition and execute the following block
2581 if it evaluates true.
2586 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2587 conditional \(em if none of the conditions of the preceeding
2591 commands was true, the
2597 (en) Marks the end of an
2598 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2599 conditional execution block.
2603 \*(OP Since \*(UA uses the console as a user interface it can happen
2604 that messages scroll by too fast to become recognized.
2605 Optionally an error message ring queue is available which stores
2606 duplicates of any error message and notifies the user in interactive
2607 sessions whenever a new error has occurred.
2608 The queue is finite: if its maximum size is reached any new message
2609 replaces the eldest.
2612 can be used to manage this message queue: if given
2614 or no argument the queue will be displayed and cleared,
2616 will only clear all messages from the queue.
2620 (ex or x) Exit from \*(UA without changing the active mailbox and skip
2621 any saving of messages in
2623 as well as a possibly tracked command line editor history file.
2627 Print the list of features that have been compiled into \*(UA.
2633 but open the mailbox readonly.
2637 (fi) The file command switches to a new mailbox.
2638 Without arguments it prints the complete state of the current mailbox.
2639 If an argument is given, it will write out changes (such as deletions)
2640 the user has made and open a new mailbox.
2641 Some special conventions are recognized for the
2645 .Bl -tag -compact -offset indent -width ".Ar %:__lespec"
2647 (number sign) means the previous file,
2649 (percent sign) means the invoking user's system mailbox, which either is
2650 the (itself expandable)
2652 if that is set, the standardized absolute pathname indicating
2654 if that is set, or a builtin compile-time default otherwise.
2655 (\*(OB For IMAP folders only, and only if
2657 is not set, the value of
2659 is inspected and used if found.)
2661 means the system mailbox of
2663 (and never the value of
2667 regardless of their actual setting),
2669 (ampersand) means the invoking user's
2679 expands to the same value as
2681 but the file is handled as a system mailbox by, e.g., the
2685 commands, meaning that messages that have been read in the current
2686 session will be moved to the
2688 mailbox instead of simply being flagged as read.
2691 If the name matches one of the strings defined with the command
2693 it is replaced by its long form and expanded.
2694 If the name ends with
2699 it is treated as being compressed with
2704 respectively, and transparently handled through an intermediate
2705 (un)compression step (using a temporary file) with the according
2706 facility, sufficient support provided.
2707 Likewise, if the named file doesn't exist, but a file with one of the
2708 mentioned compression extensions does, then the name is automatically
2709 expanded and the compressed file is used.
2711 Otherwise, if the name ends with an extension for which
2712 .Va file-hook-load-EXTENSION
2714 .Va file-hook-save-EXTENSION
2715 variables are set, then the given hooks will be used to load and save
2717 and \*(UA will work with an intermediate temporary file.
2719 MBOX files (flat file-based mailboxes) are generally locked during file
2720 operations in order to avoid inconsistencies against concurrent
2722 Mailbox files which \*(UA treats as system mailboxes will also be
2723 protected by so-called dotlock files, the traditional way of mail spool
2724 file locking: for any file
2728 will be created for the duration of the synchronization \(em
2729 as necessary a privilege-separated dotlock child process will be used
2730 to accommodate for necessary privilege adjustments in order to create
2731 the dotlock file in the same directory
2732 and with the same user and group identities as the file of interest.
2736 refers to a directory with the subdirectories
2741 then it is treated as a folder in
2746 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
2747 .Dl \*(OU protocol://[user@]host[:port][/path]
2749 is taken as an Internet mailbox specification.
2750 The \*(OPally supported protocols are
2754 (POP3 with SSL/TLS encrypted transport).
2757 part is valid only for IMAP; there it defaults to
2759 Also see the section
2760 .Sx "On URL syntax and credential lookup" .
2764 contains special characters, in particular
2768 they must be escaped in URL notation \(en the command
2770 can be used to show the necessary conversion.
2771 The optional `path' part applies to IMAP only;
2772 if it is omitted, the default `INBOX' is used.
2774 If \*(UA is connected to an IMAP server,
2775 a name of the form `@mailbox' refers to the `mailbox' on that server,
2776 but otherwise a `@' prefix has no special meaning.
2780 Takes a message list and marks the messages as
2782 ged for urgent/special attention.
2783 This mark has no technical meaning in the mail system;
2784 it just causes messages to be highlighted in the header summary,
2785 and makes them specially addressable.
2794 With no arguments, list the names of the folders in the folder directory.
2795 With an existing folder as an argument,
2796 lists the names of folders below the named folder;
2797 e.\|g. the command `folders @' lists the folders on the base level of
2798 the current IMAP server.
2799 See also the variable
2800 .Va imap-list-depth .
2806 but saves the message in a file named after the local part of the first
2807 recipient's address (instead of in
2814 but saves the message in a file named after the local part of the first
2815 recipient's address (instead of in
2822 but responds to all recipients regardless of the
2827 .It Ic followupsender
2830 but responds to the sender only regardless of the
2846 (f) Takes a list of messages and prints their message headers
2847 (which qualifies this command as \*(UAs search facility).
2853 but saves the message in a file named after the local part of the
2854 recipient's address (instead of in
2859 Takes a message and the address of a recipient
2860 and forwards the message to him.
2861 The text of the original message is included in the new one,
2862 with the value of the
2864 variable printed before.
2869 commands specify which header fields are included in the new message.
2870 Only the first part of a multipart message is included unless the
2871 .Va forward-as-attachment
2875 is set recipient addresses will be stripped from comments, names etc.
2879 Specifies which header fields are to be ignored with the command
2881 This command has no effect when the
2882 .Va forward-as-attachment
2887 Specifies which header fields are to be retained with the command
2892 This command has no effect when the
2893 .Va forward-as-attachment
2898 Define or list command aliases, so-called ghosts.
2899 Without arguments a list of all currently known aliases is printed.
2900 With one argument the expansion of the given alias is shown.
2901 With two or more arguments a command alias is defined or updated: the
2902 first argument is the name under which the remaining command line should
2903 be accessible, the content of which can be just about anything.
2904 A ghost can be used everywhere a normal command can be used, but always
2905 takes precedence; any arguments that are given to the command alias are
2906 joined onto the alias content, and the resulting string forms the
2907 command line that is, in effect, executed.
2910 .Bd -literal -offset indent
2912 `ghost': no such alias: "xx"
2915 ghost xx "echo hello,"
2924 (h) Show the current group of headers, the size of which depends on
2927 If a message-specification is given the group of headers containing the
2928 first message therein is shown and the message at the top of the screen
2943 the list of history entries;
2946 argument selects and shows the respective history entry \(en
2949 to accept it, and the history entry will become the new history top.
2950 The default mode if no arguments are given is
2957 Takes a message list and marks each message therein to be saved in the
2958 user's system mailbox instead of in
2960 Does not override the
2963 \*(UA deviates from the POSIX standard with this command, because a
2965 command issued after
2967 will display the following message, not the current one.
2972 (i) Part of the nestable
2973 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2974 conditional execution construct \(em if the given condition is true then
2975 the encapsulated block is executed.
2976 POSIX only supports the conditions
2981 (execute if standard input is a tty), all remaining conditions are
2982 non-portable extensions; note that falsely specified conditions cause
2983 the execution of the entire conditional construct until the
2986 command to be suppressed.
2987 The syntax of the nestable
2989 conditional execution construct requires that each condition and syntax
2990 element is surrounded by whitespace.
2992 .Bd -literal -offset indent
3001 Another condition can be any boolean value (see the section
3003 for booleans) to mark an enwrapped block as
3006 .Dq always execute .
3007 It is possible to check a variable for existence or compare its
3008 expansion against a user given value or another variable via the
3010 .Pf ( Dq variable next )
3011 conditional trigger character.
3012 The available comparison operators are
3016 (less than or equal to),
3022 (greater than or equal to),
3026 (is substring of) and
3028 (is not substring of).
3029 The values of the left and right hand side are treated as strings and
3030 are compared 8-bit byte-wise, ignoring case according to the rules of
3031 the US-ASCII encoding (therefore, dependend on the active locale,
3032 possibly producing false results for strings in the locale encoding).
3033 Except for the substring checks the comparison will instead be performed
3034 arithmetically if both, the user given value as well as the variable
3035 content, can be parsed as numbers (integers).
3036 An unset variable is treated as the empty string.
3039 When the \*(OPal regular expression support is available, the additional
3045 They treat the right hand side as a regular expression that is matched
3046 case-insensitively and according to the active
3048 locale, meaning that strings in the locale encoding should be matched
3052 Conditions can be joined via AND-OR lists (where the AND operator is
3054 and the OR operator is
3056 which have equal precedence and will be evaluated with left
3057 associativity, thus using the same syntax that is known for the
3059 It is also possible to form groups of conditions and lists by enclosing
3060 them in pairs of brackets
3061 .Ql [\ \&.\&.\&.\ ] ,
3062 which may be interlocked within each other, and also be joined via
3066 The results of individual conditions and entire groups may be modified
3067 via unary operators: the unary operator
3069 will reverse the result.
3071 .Bd -literal -offset indent
3075 if $ttycharset == "UTF-8"
3076 echo *ttycharset* is set to UTF-8, case-insensitively
3080 echo These two variables are equal
3082 if $version-major >= 15
3083 echo Running a new version..
3084 if $features =@ "regex"
3085 if $TERM =~ "^xterm\&.*"
3086 echo ..in an X terminal
3089 if [ [ true ] && [ [ $debug ] || [ $verbose ] ] ]
3092 if true && $debug || $verbose
3093 echo Left associativity, as is known from the shell
3095 if ! ! true && ! [ ! $debug && ! $verbose ]
3096 echo Unary operator support
3104 Without arguments the list of ignored header fields is printed,
3105 otherwise the given list of header fields is added to the ignore list:
3106 Header fields in the ignore list are not printed on the terminal when
3107 a message is printed.
3108 To print a message in its entirety, use the commands
3119 \*(OP Sends command strings directly to the current IMAP server.
3120 \*(UA operates always in IMAP `selected state' on the current mailbox;
3121 commands that change this will produce undesirable results and should be
3123 Useful IMAP commands are:
3124 .Bl -tag -offset indent -width ".Ic getquotearoot"
3126 Takes the name of an IMAP mailbox as an argument and creates it.
3128 (RFC 2087) Takes the name of an IMAP mailbox as an argument
3129 and prints the quotas that apply to the mailbox.
3130 Not all IMAP servers support this command.
3132 (RFC 2342) Takes no arguments and prints the Personal Namespaces,
3133 the Other User's Namespaces and the Shared Namespaces.
3134 Each namespace type is printed in parentheses;
3135 if there are multiple namespaces of the same type,
3136 inner parentheses separate them.
3137 For each namespace a prefix and a hierarchy separator is listed.
3138 Not all IMAP servers support this command.
3148 Prints the names of all available commands, alphabetically sorted.
3152 This command can be used to localize changes to variables, meaning that
3153 their state will be reverted to the former one once the covered scope
3155 It can only be used inside of macro definition blocks introduced by
3159 and is interpreted as a boolean (see
3160 .Sx "Value options" ) ;
3163 of an account is left once it is switched off again.
3164 .Bd -literal -offset indent
3165 define temporary_settings {
3180 enables change localization and calls
3182 which explicitly resets localization, then any value changes within
3184 will still be reverted by
3189 Reply to messages that come in via known
3192 .Pf ( Ic mlsubscribe )
3193 mailing lists, or pretend to do so (see
3194 .Sx "Mailing lists" ) :
3197 functionality this will actively resort and even remove message
3198 recipients in order to generate a message that is supposed to be send to
3200 For example it will also implicitly generate a
3201 .Ql Mail-Followup-To:
3202 header if that seems useful, regardless of the setting of the variable
3209 but saves the message in a file named after the local part of the first
3210 recipient's address (instead of in
3215 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3216 or asks on standard input if none were given;
3217 then collects the remaining mail content and sends it out.
3221 (mb) The given message list is to be sent to
3223 when \*(UA is quit; this is the default action unless the
3226 \*(ID This command can only be used in a system mailbox (see
3231 Without any arguments the content of the MIME type cache will displayed.
3232 Otherwise each argument defines a complete MIME type specification of
3233 a type that shall be added (prepended) to the cache.
3234 In any event MIME type sources are loaded first as necessary \(en
3235 .Va mimetypes-load-control
3236 can be used to fine-tune which sources are actually loaded.
3237 Refer to the section on
3238 .Sx "The mime.types files"
3239 for more on MIME type specifications and this topic in general.
3240 MIME type unregistration and cache resets can be triggered with
3245 Without arguments the list of all currently defined mailing lists
3246 (and their attributes, if any) is printed.
3247 Otherwise all given arguments (which need not be quoted except for
3248 whitespace) will be added and henceforth be recognized as mailing lists.
3249 Mailing lists may be removed via the command
3252 If the \*(OPal regular expression support is available then mailing
3253 lists may also be specified as regular expressions (see
3259 Without arguments the list of all currently defined mailing lists which
3260 have a subscription attribute is printed.
3261 Otherwise this attribute will be set for all given mailing lists,
3262 newly creating them as necessary (as via
3264 Subscription attributes may be removed via the command
3273 but moves the messages to a file named after the local part of the
3274 sender address of the first message (instead of in
3281 but marks the messages for deletion if they were transferred
3288 but also prints ignored header fields and all MIME parts.
3296 on the given messages, even in non-interactive mode and as long as the
3297 standard output is a terminal.
3309 cache, loading the file first as necessary in the former case.
3310 Note that \*(UA will try to read the file only once, use
3311 .Ql Ic netrc Ns \:\0\:clear
3312 to unlock the next attempt.
3316 .Sx "On URL syntax and credential lookup" ;
3318 .Sx "The .netrc file"
3319 documents the file format in detail.
3323 Checks for new mail in the current folder without committing any changes
3325 If new mail is present, a message is printed.
3329 the headers of each new message are also printed.
3337 Goes to the next message in sequence and types it.
3338 With an argument list, types the next matching message.
3352 If the current folder is accessed via a network connection, a
3354 command is sent, otherwise no operation is performed.
3360 but also prints ignored header fields and all MIME parts.
3368 on the given messages, even in non-interactive mode and as long as the
3369 standard output is a terminal.
3377 but also pipes ignored header fields and all parts of MIME
3378 .Ql multipart/alternative
3383 (pi) Takes a message list and a shell command
3384 and pipes the messages through the command.
3385 Without an argument the current message is piped through the command
3392 every message is followed by a formfeed character.
3403 but also prints out ignored header fields and all parts of MIME
3404 .Ql multipart/alternative
3414 (p) Takes a message list and types out each message on the user's
3416 For MIME multipart messages, all parts with a content type of
3420 are shown, the other are hidden except for their headers.
3421 Messages are decrypted and converted to the terminal character set
3426 (q) Terminates the session, saving all undeleted, unsaved messages in
3429 preserving all messages marked with
3433 or never referenced in the system mailbox,
3434 and removing all other messages from the system mailbox.
3435 If new mail has arrived during the session,
3437 .Dq You have new mail
3439 If given while editing a mailbox file with the command line flag
3441 then the edit file is rewritten.
3442 A return to the shell is effected,
3443 unless the rewrite of edit file fails,
3444 in which case the user can escape with the exit command.
3458 Removes the named folders.
3459 The user is asked for confirmation in interactive mode.
3463 Takes the name of an existing folder
3464 and the name for the new folder
3465 and renames the first to the second one.
3466 Both folders must be of the same type
3467 and must be located on the current server for IMAP.
3471 (R) Reply to originator.
3472 Does not reply to other recipients of the original message.
3474 will exchange this command with
3478 is set the recipient address will be stripped from comments, names etc.
3482 (r) Take a message and group-responds to it by addressing the sender
3485 .Va followup-to-honour ,
3488 .Va recipients-in-cc
3489 influence response behaviour.
3492 offers special support for replying to mailing lists.
3495 is set recipient addresses will be stripped from comments, names etc.
3508 but initiates a group-reply regardless of the value of
3515 but responds to the sender only regardless of the value of
3522 but does not add any header lines.
3523 This is not a way to hide the sender's identity,
3524 but useful for sending a message again to the same recipients.
3528 Takes a list of messages and a user name
3529 and sends each message to the named user.
3531 and related header fields are prepended to the new copy of the message.
3549 .It Ic respondsender
3555 (ret) Without arguments the list of retained header fields is printed,
3556 otherwise the given list of header fields is added to the retain list:
3557 Header fields in the retain list are shown on the terminal when
3558 a message is printed, all other header fields are suppressed.
3559 To print a message in its entirety, use the commands
3568 takes precedence over the mentioned.
3574 but saves the messages in a file named after the local part of the
3575 sender of the first message instead of (in
3577 and) taking a filename argument.
3581 (s) Takes a message list and a filename and appends each message in turn
3582 to the end of the file.
3583 If no filename is given, the
3586 The filename in quotes, followed by the generated character count
3587 is echoed on the user's terminal.
3588 If editing a system mailbox the messages are marked for deletion.
3589 Compressed files and IMAP mailboxes are handled as described for the
3591 command line option above.
3608 Header fields thus marked are filtered out when saving a message by
3610 or when automatically saving to
3612 This command should only be applied to header fields that do not contain
3613 information needed to decode the message,
3614 as MIME content fields do.
3615 If saving messages on an IMAP account ignoring fields makes it
3616 impossible to copy the data directly on the server,
3617 thus operation usually becomes much slower.
3629 Header fields thus marked are the only ones saved with a message when
3632 or when automatically saving to
3637 The use of this command is strongly discouraged since it may strip
3638 header fields that are needed to decode the message correctly.
3642 Takes a message list and marks all messages as having been read.
3646 (se) Without arguments this command prints all options and, for
3647 non-binary options, values that are currently known to \*(UA.
3648 Setting any of the options
3652 changes the output format to BSD style, otherwise a properly quoted
3653 listing is produced.
3658 has been set twice then the listing is modified to mark out assembled
3661 Otherwise modifies (set and unsets) the given options.
3662 Arguments are of the form
3664 (no space before or after
3668 if there is no value.
3669 Quotation marks may be placed around any part of the assignment
3670 statement to quote blanks or tabs, e.g.,
3672 .Dl set indentprefix="->"
3674 If an argument begins with
3678 the effect is the same as invoking the
3680 command with the remaining part of the variable
3681 .Pf ( Ql unset save ) .
3687 except that the options are also exported into the program environment;
3688 since this task requires native host support the command will always
3689 report error if that is not available (but still act like
3692 This operation is a no-op unless all resource files have been loaded.
3698 (sh) Invokes an interactive version of the shell.
3702 Without arguments the list of all currently defined shortcuts is
3704 Otherwise all given arguments (which need not be quoted except for
3705 whitespace) are treated as pairs of shortcuts and their expansions,
3706 creating new or changing already existing shortcuts, as necessary.
3707 Shortcuts may be removed via the command
3709 The expansion strings should be in the syntax that has been described
3718 but performs neither MIME decoding nor decryption, so that the raw
3719 message text is shown.
3723 (si) Print the size in characters of each message of the given
3728 Create a sorted representation of the current folder,
3731 command and the addressing modes such that they refer to messages in the
3733 Message numbers are the same as in regular mode.
3737 a header summary in the new order is also printed.
3738 Possible sorting criteria are:
3740 .Bl -tag -compact -offset indent -width "subject"
3742 Sort the messages by their
3744 field, that is by the time they were sent.
3746 Sort messages by the value of their
3748 field, that is by the address of the sender.
3751 variable is set, the sender's real name (if any) is used.
3753 Sort the messages by their size.
3755 \*(OP Sort the message by their spam score, as has been classified by
3758 Sort the messages by their message status.
3760 Sort the messages by their subject.
3762 Create a threaded display.
3764 Sort messages by the value of their
3766 field, that is by the address of the recipient.
3769 variable is set, the recipient's real name (if any) is used.
3772 If no argument is given,
3773 the current sorting criterion is printed.
3777 (so) The source command reads commands from a file.
3783 is that this command will not generate an error if the given file
3784 argument cannot be opened successfully.
3785 This can matter in, e.g., resource files, since loading of those is
3786 stopped when an error is encountered.
3790 \*(OP Takes a list of messages and clears their
3796 \*(OP Takes a list of messages and causes the
3798 to forget it has ever used them to train its Bayesian filter.
3799 Unless otherwise noted the
3801 flag of the message is inspected to chose whether a message shall be
3809 \*(OP Takes a list of messages and informs the Bayesian filter of the
3813 This also clears the
3815 flag of the messages in question.
3819 \*(OP Takes a list of messages and rates them using the configured
3820 .Va spam-interface ,
3821 without modifying the messages, but setting their
3823 flag as appropriate; because the spam rating headers are lost the rate
3824 will be forgotten once the mailbox is left.
3825 Refer to the manual section
3827 for the complete picture of spam handling in \*(UA.
3831 \*(OP Takes a list of messages and sets their
3837 \*(OP Takes a list of messages and informs the Bayesian filter of the
3843 flag of the messages in question.
3852 Create a threaded representation of the current folder,
3853 i.\|e. indent messages that are replies to other messages in the header
3854 display and change the
3856 command and the addressing modes such that they refer to messages in the
3858 Message numbers are the same as in unthreaded mode.
3862 a header summary in threaded order is also printed.
3866 (to) Takes a message list and prints the top few lines of each.
3867 The number of lines printed is controlled by the variable
3869 and defaults to five.
3873 (tou) Takes a message list and marks the messages for saving in
3875 \*(UA deviates from the POSIX standard with this command,
3878 command will display the following message instead of the current one.
3882 (T) Identical to the
3893 Delete all given accounts.
3894 An error message is printed if a given account is not defined.
3897 will discard all existing accounts.
3901 (una) Takes a list of names defined by alias commands
3902 and discards the remembered groups of users.
3905 will discard all existing aliases.
3909 Takes a message list and marks each message as not having been answered.
3913 Only applicable to threaded mode.
3914 Takes a message list and makes the message and all replies to it visible
3915 in header summaries again.
3916 When a message becomes the current message,
3917 it is automatically made visible.
3918 Also when a message with collapsed replies is printed,
3919 all of these are automatically uncollapsed.
3923 Undefine all given macros.
3924 An error message is printed if a given macro is not defined.
3927 will discard all existing macros.
3931 (u) Takes a message list and marks each message as not being deleted.
3935 Takes a message list and
3941 Takes a message list and marks each message as not being
3946 Removes the header field names from the list of ignored fields for the
3951 will remove all fields.
3955 Removes the header field names from the list of retained fields for the
3960 will remove all fields.
3964 Remove all the given command
3968 will remove all ghosts.
3972 Removes the header field names from the list of ignored fields.
3975 will remove all fields.
3979 Delete all given MIME types, e.g.,
3980 .Ql unmimetype text/plain
3981 will remove all registered specifications for the MIME type
3985 will discard all existing MIME types, just as will
3987 but which also reenables cache initialization via
3988 .Va mimetypes-load-control .
3992 Forget about all the given mailing lists.
3995 will remove all lists.
4000 .It Ic unmlsubscribe
4001 Remove the subscription attribute from all given mailing lists.
4004 will clear the attribute from all lists which have it set.
4015 Takes a message list and marks each message as not having been read.
4019 Removes the header field names from the list of retained fields.
4022 will remove all fields.
4026 Removes the header field names from the list of ignored fields for
4030 will remove all fields.
4034 Removes the header field names from the list of retained fields for
4038 will remove all fields.
4042 (uns) Takes a list of option names and discards their remembered values;
4050 except that the options are also removed from the program environment;
4051 since this task requires native host support the command will always
4052 report error if that is not available (but still act like
4055 This operation is a no-op unless all resource files have been loaded.
4061 Deletes the shortcut names given as arguments.
4064 will remove all shortcuts.
4068 Disable sorted or threaded mode
4074 return to normal message order and,
4078 print a header summary.
4088 Decode the given URL-encoded string arguments and show the results.
4092 URL-encode the given arguments and show the results.
4096 Edit the values of or create the given variable(s) in the
4098 Binary variables cannot be edited.
4102 Show informations about all the given options.
4103 \*(UA knows about a finite set of known builtin variables that are
4104 subdivided further in binary and value variants;
4105 they may have special properties, like
4107 (setting may not be changed) and
4109 meaning that the value is generated on-the-fly as necessary.
4110 Beside those known variables an infinite number of unknown, so-called
4112 variables, which are expected to be able to store values, may exist.
4113 .Bd -literal -offset indent
4115 ? varshow sendwait version-major foo bar
4116 "sendwait": (73) binary: set=1 (ENVIRON=0)
4117 "version-major": (192) value, read-only, virtual:\e
4118 set=1 (ENVIRON=0) value<14>
4119 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4120 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4125 \*(OP Takes a message list and verifies each message.
4126 If a message is not a S/MIME signed message,
4127 verification will fail for it.
4128 The verification process checks if the message was signed using a valid
4130 if the message sender's email address matches one of those contained
4131 within the certificate,
4132 and if the message content has been altered.
4136 (v) Takes a message list and invokes the display editor on each message.
4137 Modified contents are discarded unless the
4143 (w) For conventional messages the body without all headers is written.
4144 The output is decrypted and converted to its native format as necessary.
4145 If the output file exists, the text is appended.
4146 If a message is in MIME multipart format its first part is written to
4147 the specified file as for conventional messages,
4148 and the user is asked for a filename to save each other part.
4149 For convience saving of each part may be skipped by giving an empty value;
4150 the same result can also be achieved by writing it to
4152 For the second and subsequent parts a leading
4154 character causes the part to be piped to the remainder of the user input
4155 interpreted as a shell command;
4156 otherwise the user input is expanded as usually for folders,
4157 e.g., tilde expansion is performed.
4158 In non-interactive mode, only the parts of the multipart message
4159 that have a filename given in the part header are written,
4160 the others are discarded.
4161 The original message is never marked for deletion in the originating
4164 the contents of the destination file are overwritten if the file
4166 No special handling of compressed files is performed.
4175 \*(UA presents message headers in
4177 fuls as described under the
4180 Without arguments this command scrolls to the next window of messages,
4181 likewise if the argument is
4185 scrolls to the last,
4187 scrolls to the first, and
4192 A number argument prefixed by
4196 indicates that the window is calculated in relation to the current
4197 position, and a number without a prefix specifies an absolute position.
4203 but scrolls to the next or previous window that contains at least one
4212 .\" .Sh TILDE ESCAPES {{{
4215 Here is a summary of the tilde escapes,
4216 which are used to perform special functions when composing messages.
4217 Tilde escapes are only recognized at the beginning of lines.
4220 is somewhat of a misnomer since the actual escape character can be
4221 changed by adjusting the option
4224 .Bl -tag -width ".Ic __ filename"
4227 Insert the string of text in the message prefaced by a single
4229 (If the escape character has been changed,
4230 that character must be doubled
4231 in order to send it at the beginning of a line.)
4234 .It Ic ~! Ar command
4235 Execute the indicated shell
4237 then return to the message.
4241 Same effect as typing the end-of-file character.
4244 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4245 Execute the given \*(UA command.
4246 Not all commands, however, are allowed.
4250 Write a summary of command escapes.
4253 .It Ic ~< Ar filename
4258 .It Ic ~<! Ar command
4260 is executed using the shell.
4261 Its standard output is inserted into the message.
4264 .It Ic ~@ Op Ar filename...
4265 With no arguments, edit the attachment list interactively.
4266 If an attachment's file name is left empty,
4267 that attachment is deleted from the list.
4268 When the end of the attachment list is reached,
4269 \*(UA will ask for further attachments until an empty name is given.
4270 If a given file name solely consists of the number sign
4272 followed by a valid message number of the currently active mailbox, then
4273 the given message is attached as a MIME
4275 and the rest of this section does not apply.
4277 If character set conversion has been compiled into \*(UA, then this mode
4278 gives the user the option to specify input and output character sets,
4279 unless the file extension indicates binary content, in which case \*(UA
4280 asks whether this step shall be skipped for the attachment in question.
4281 If not skipped, then the charset that succeeds to represent the
4282 attachment data will be used in the
4284 MIME parameter of the mail message:
4286 .Bl -bullet -compact
4288 If input and output character sets are specified, then the conversion is
4289 performed on the fly.
4290 The user will be asked repeatedly until the desired conversion succeeds.
4292 If only an output character set is specified, then the input is assumed
4295 charset and will be converted to the given output charset on the fly.
4296 The user will be asked repeatedly until the desired conversion succeeds.
4298 If no character sets are specified at all then the algorithm that is
4299 documented in the section
4300 .Sx "Character sets"
4301 is applied, but directly and on the fly.
4302 The user will be asked repeatedly until the desired conversion succeeds.
4304 Finally, if an input-, but no output character set is specified, then no
4305 conversion is ever performed, but the
4307 MIME parameter value will still be set to the user input.
4309 The character set selection loop can be left by typing
4311 i.e., causing an interrupt.
4312 .\" \*(OU next sentence
4313 Note that before \*(UA version 15.0 this terminates the entire
4314 current attachment selection, not only the character set selection.
4317 Without character set conversion support, \*(UA will ask for the input
4318 character set only, and it'll set the
4320 MIME parameter value to the given input, if any;
4321 if no user input is seen then the
4323 character set will be used for the parameter value instead.
4324 Note that the file extension check isn't performed in this mode, since
4325 no conversion will take place anyway.
4327 Note that in non-interactive mode, for reproduceabilities sake, there
4328 will always be two questions for each attachment, regardless of whether
4329 character set conversion is available and what the file extension is.
4330 The first asks for the filename, and the second asks for the input
4331 character set to be passed through to the corresponding MIME parameter;
4332 no conversion will be tried if there is input to the latter question,
4333 otherwise the usual conversion algorithm, as above, is applied.
4334 For message attachments, the answer to the second question is completely
4339 arguments are specified for the
4341 command they are treated as a comma separated list of files,
4342 which are all expanded and appended to the end of the attachment list.
4343 (Filenames with commas, or with leading or trailing whitespace can only
4344 be added via the command line or the first method.
4345 Message attachments can only be added via the first method;
4346 filenames which clash with message numbers can only be added via the
4347 command line or the second method.)
4348 In this mode the (text) attachments are assumed to be in
4350 encoding, and will be evaluated as documented in the section
4351 .Sx "Character sets" .
4355 Inserts the string contained in the
4358 .Ql Ic ~i Ns \0Sign ) .
4359 The escape sequences tabulator
4367 Inserts the string contained in the
4370 .Ql Ic ~i Ns \0sign ) .
4371 The escape sequences tabulator
4378 .It Ic ~b Ar name ...
4379 Add the given names to the list of blind carbon copy recipients.
4382 .It Ic ~c Ar name ...
4383 Add the given names to the list of carbon copy recipients.
4387 Read the file specified by the
4389 variable into the message.
4393 Invoke the text editor on the message collected so far.
4394 After the editing session is finished,
4395 the user may continue appending text to the message.
4398 .It Ic ~F Ar messages
4399 Read the named messages into the message being sent, including all
4400 message headers and MIME parts.
4401 If no messages are specified, read in the current message.
4404 .It Ic ~f Ar messages
4405 Read the named messages into the message being sent.
4406 If no messages are specified, read in the current message.
4410 lists are used to modify the message headers.
4411 For MIME multipart messages,
4412 only the first printable part is included.
4416 Edit the message header fields
4422 by typing each one in turn and allowing the user to edit the field.
4423 The default values for these fields originate from the
4424 .Va from , replyto , sender
4431 Edit the message header fields
4437 by typing each one in turn and allowing the user to edit the field.
4440 .It Ic ~i Ar variable
4441 Insert the value of the specified variable into the message,
4442 adding a newline character at the end.
4443 The message remains unaltered if the variable is unset or empty.
4444 The escape sequences tabulator
4451 .It Ic ~M Ar messages
4452 Read the named messages into the message being sent,
4455 If no messages are specified, read the current message.
4458 .It Ic ~m Ar messages
4459 Read the named messages into the message being sent,
4462 If no messages are specified, read the current message.
4466 lists are used to modify the message headers.
4467 For MIME multipart messages,
4468 only the first printable part is included.
4472 Print out the message collected so far,
4473 prefaced by the message header fields
4474 and followed by the attachment list, if any.
4478 Abort the message being sent,
4479 copying it to the file specified by the
4486 .It Ic ~R Ar filename
4487 Read the named file into the message, indented by
4491 .It Ic ~r Ar filename
4492 Read the named file into the message.
4496 Cause the named string to become the current subject field.
4499 .It Ic ~t Ar name ...
4500 Add the given name(s) to the direct recipient list.
4503 .It Ic ~U Ar messages
4504 Read in the given / current message(s) excluding all headers, indented by
4508 .It Ic ~u Ar messages
4509 Read in the given / current message(s), excluding all headers.
4513 Invoke an alternate editor (defined by the
4515 option) on the message collected so far.
4516 Usually, the alternate editor will be a screen editor.
4517 After the editor is quit,
4518 the user may resume appending text to the end of the message.
4521 .It Ic ~w Ar filename
4522 Write the message onto the named file.
4524 the message is appended to it.
4530 except that the message is not saved at all.
4533 .It Ic ~| Ar command
4534 Pipe the message through the specified filter command.
4535 If the command gives no output or terminates abnormally,
4536 retain the original text of the message.
4539 is often used as a rejustifying filter.
4544 .\" .Sh VARIABLE OPTIONS {{{
4545 .Sh "VARIABLE OPTIONS"
4547 Variables are controlled via
4551 commands; in general using
4553 can also be accomplished by prefixing a variable name with the string
4559 will have the same effect as
4561 Creation or editing of variables in an editor can also be achieved with
4564 will give more insight on the given variable(s), whereas
4566 will print a listing of all variables when called without arguments.
4567 Options are also implicitly inherited from the program
4569 and can be set explicitly via the command line option
4573 Different kind of options exist:
4574 binary options, which can only be in one of the two states
4578 as well as value options which have an assigned string value, for which
4579 proper quoting may be important upon assignment time.
4581 .\" .Ss "Initial settings" {{{
4582 .\" (Keep in sync: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
4583 .Ss "Initial Settings"
4585 The standard POSIX 2008/Cor 1-2013 mandates the following initial
4591 .Pf no Va autoprint ,
4605 .Pf no Va ignoreeof ,
4607 .Pf no Va keepsave ,
4609 .Pf no Va outfolder ,
4614 (note that \*(UA deviates from the standard by using
4618 special prompt escape results in
4620 being printed unless
4626 .Pf no Va sendwait ,
4635 Notes: \*(UA doesn't support the
4637 variable \(en use command line options or
4638 .Va sendmail-arguments
4639 to pass options through to a MTA.
4640 And the default global
4642 file (which is loaded unless the
4644 command line flag has been used or the
4645 .Ev NAIL_NO_SYSTEM_RC
4646 environment variable is set) bends those initial settings a bit, e.g.,
4652 to name a few, calls
4654 etc., and should thus be taken into account.
4657 .\" .Ss "Binary options" {{{
4658 .Ss "Binary options"
4660 .Bl -tag -width ".Va _utoprin_"
4662 .It Va add-file-recipients
4663 When file or pipe recipients have been specified,
4664 mention them in the corresponding address fields of the message instead
4665 of silently stripping them from their recipient list.
4666 By default such addressees are not mentioned.
4670 Causes only the local part to be evaluated
4671 when comparing addresses.
4675 Causes messages saved in
4677 to be appended to the end rather than prepended.
4678 This should always be set.
4682 .It Va ask Ns \0or Va asksub
4683 Causes \*(UA to prompt for the subject of each message sent.
4684 If the user responds with simply a newline,
4685 no subject field will be sent.
4689 Causes the prompts for
4693 lists to appear after the message has been edited.
4697 If set, \*(UA asks for files to attach at the end of each message, shall
4698 the list be found empty at that time.
4699 An empty line finalizes the list.
4703 Causes the user to be prompted for carbon copy recipients
4704 (at the end of each message if
4708 are set) shall the list be found empty (at that time).
4709 An empty line finalizes the list.
4713 Causes the user to be prompted for blind carbon copy
4714 recipients (at the end of each message if
4718 are set) shall the list be found empty (at that time).
4719 An empty line finalizes the list.
4723 \*(OP Causes the user to be prompted if the message is to be signed at
4724 the end of each message.
4727 variable is ignored when this variable is set.
4731 Causes threads to be collapsed automatically when threaded mode is
4738 Causes the delete command to behave like
4740 thus, after deleting a message the next one will be typed automatically.
4744 \*(OB Causes threaded mode (see the
4746 command) to be entered automatically when a folder is opened.
4748 .Ql autosort=thread .
4752 Enables the substitution of
4754 by the contents of the last command line in shell escapes.
4757 .It Va batch-exit-on-error
4758 If the batch mode has been enabled via the
4760 command line option, then this variable will be consulted whenever \*(UA
4761 completes one operation (returns to the command prompt); if it is set
4762 then \*(UA will terminate if the last operation generated an error.
4766 Causes automatic display of a header summary after executing a
4772 Sets some cosmetical features to traditional BSD style;
4773 has the same affect as setting
4775 and all other variables prefixed with
4777 it also changes the meaning of the \*(UA specific
4784 Changes the letters printed in the first column of a header summary
4785 to traditional BSD style.
4789 Changes the display of columns in a header summary to traditional BSD
4794 Changes some informational messages to traditional BSD style.
4800 field to appear immediately after the
4802 field in message headers and with the
4804 .Sx "TILDE ESCAPES" .
4808 Changes the output format of the
4810 command to traditional BSD style.
4813 .It Va colour-disable
4814 \*(OP Forcefully disable usage of colours.
4815 Also see the section
4816 .Sx "Coloured message display" .
4820 \*(OP Whether colour shall be used for output that is paged through
4822 Note that pagers may need special flags, e.g.,
4830 in order to support colours; therefore \*(UA will inspect the variable
4832 \(en if that starts with the string
4834 a non-existing environment variable
4841 will optionally be set to
4843 Also see the section
4844 .Sx "Coloured message display"
4849 Prints debugging messages and disables the actual delivery of messages.
4857 \*(OP When an IMAP mailbox is selected and this variable is set,
4858 no connection to the server is initiated.
4859 Instead, data is obtained from the local cache (see
4862 Mailboxes that are not present in the cache
4863 and messages that have not yet entirely been fetched from the server
4865 to fetch all messages in a mailbox at once,
4867 .No ` Ns Li copy * /dev/null Ns '
4868 can be used while still in connected mode.
4869 Changes that are made to IMAP mailboxes in disconnected mode are queued
4870 and committed later when a connection to that server is made.
4871 This procedure is not completely reliable since it cannot be guaranteed
4872 that the IMAP unique identifiers (UIDs) on the server still match the
4873 ones in the cache at that time.
4876 when this problem occurs.
4878 .It Va disconnected-USER@HOST
4879 The specified account is handled as described for the
4882 but other accounts are not affected.
4885 .It Va disposition-notification-send
4887 .Ql Disposition-Notification-To:
4888 header (RFC 3798) with the message.
4892 .\" TODO .It Va disposition-notification-send-HOST
4894 .\".Va disposition-notification-send
4895 .\" for SMTP accounts on a specific host.
4896 .\" TODO .It Va disposition-notification-send-USER@HOST
4898 .\".Va disposition-notification-send
4899 .\"for a specific account.
4903 When dot is set, a dot
4905 on a line by itself during message input from a terminal shall be
4906 treated as end-of-message (in addition to the normal end-of-file
4912 is ignored and using a dot is the only method to terminate input mode.
4915 .It Va dotlock-ignore-error
4916 \*(OP Synchronization of mailboxes which \*(UA treats as system
4917 mailboxes (see the command
4919 will be protected with so-called dotlock files\(emthe traditional mail
4920 spool file locking method\(emin addition to system file locking.
4921 Because \*(UA ships with a privilege-separated dotlock creation program
4922 that should always be able to create such a dotlock file there is no
4923 good reason to ignore dotlock file creation errors, and thus these are
4924 fatal unless this variable is set.
4928 If this variable is set then the editor is started automatically when
4929 a message is composed in interactive mode, as if the
4935 variable is implied for this automatically spawned editor session.
4939 When a message is edited while being composed,
4940 its header is included in the editable text.
4951 fields are accepted within the header, other fields are ignored.
4955 If the mailbox is empty \*(UA normally prints
4956 .Dq \&No mail for user
4957 and exits immediately.
4958 If this option is set \*(UA starts even with an empty mailbox.
4962 This option reverses the meanings of a set of reply commands,
4963 turning the lowercase variants, which by default address all recipients
4964 included in the header of a message
4965 .Pf ( Ic reply , respond , followup )
4966 into the uppercase variants, which by default address the sender only
4967 .Pf ( Ic Reply , Respond , Followup )
4970 .Ic replysender , respondsender , followupsender
4972 .Ic replyall , respondall , followupall
4973 are not affected by the current setting of
4979 .Ql Mail-Followup-To:
4980 header is generated when sending messages to known mailing lists.
4982 .Va followup-to-honour
4984 .Ic mlist , mlsubscribe , reply
4989 .It Va forward-as-attachment
4990 Original messages are normally sent as inline text with the
4993 and only the first part of a multipart message is included.
4994 With this option messages are sent as unmodified MIME
4996 attachments with all of their parts included.
5000 When replying to or forwarding a message \*(UA normally removes the
5001 comment and name parts of email addresses.
5002 If this variable is set such stripping is not performed,
5003 and comments, names etc. are retained.
5007 Causes the header summary to be written at startup and after commands
5008 that affect the number of messages or the order of messages in the
5009 current folder; enabled by default.
5010 The command line option
5016 .It Va history-gabby
5017 \*(OP Add more entries to the history as is normally done.
5020 .It Va history-gabby-persist
5021 \*(OP \*(UAs own NCL will not save the additional (gabby) history
5022 entries in persistent storage unless this variable is also set.
5028 This option is used to hold messages in the system mailbox by default.
5032 \*(OP Can be used to turn off the automatic conversion of domain names
5033 according to the rules of IDNA (internationalized domain names for
5035 Since the IDNA code assumes that domain names are specified with the
5037 character set, an UTF-8 locale charset is required to represent all
5038 possible international domain names (before conversion, that is).
5042 Ignore interrupt signals from the terminal while entering messages;
5043 instead echo them as
5045 characters and discard the current line.
5049 Ignore end-of-file conditions
5050 .Pf ( Ql control-D ) ,
5051 on message input, which instead can be terminated only by entering a
5054 on a line by itself or by using the
5056 .Sx "TILDE ESCAPES" .
5057 This option also applies to \*(UA command mode.
5059 .Mx Va imap-use-starttls
5060 .It Va imap-use-starttls-USER@HOST , imap-use-starttls-HOST , imap-use-starttls
5061 \*(OP Causes \*(UA to issue a `STARTTLS' command to make an unencrypted
5062 IMAP session SSL/TLS encrypted.
5063 This functionality is not supported by all servers,
5064 and is not used if the session is already encrypted by the IMAPS method.
5068 If set, an empty mailbox file is not removed.
5069 This may improve the interoperability with other mail user agents
5070 when using a common folder directory, and prevents malicious users
5071 from creating fake mailboxes in a world-writable spool directory.
5072 Note this only applies to local regular (MBOX) files, other mailbox
5073 types will never be removed.
5077 When a message is saved it is usually discarded from the originating
5078 folder when \*(UA is quit.
5079 Setting this option causes all saved message to be retained.
5082 .It Va line-editor-disable
5083 Turn off any enhanced command line editing capabilities (see
5084 .Sx "Command line editor"
5089 When a message is replied to and this variable is set,
5090 it is marked as having been answered.
5091 This mark has no technical meaning in the mail system;
5092 it just causes messages to be marked in the header summary,
5093 and makes them specially addressable.
5096 .It Va message-id-disable
5097 By setting this option the generation of
5099 can be completely suppressed, effectively leaving this task up to the
5100 mail-transfer-agent (MTA) or the SMTP server.
5101 (According to RFC 5321 your SMTP server is not required to add this
5102 field by itself, so you should ensure that it accepts messages without a
5109 expansion contains the sender, the sender is removed from the expansion.
5110 Setting this option suppresses these removals.
5115 option to be passed to mail-transfer-agents (MTAs);
5116 though most of the modern MTAs don't (no longer) document this flag, no
5117 MTA is known which doesn't support it (for historical compatibility).
5120 .It Va mime-allow-text-controls
5121 When sending messages, each part of the message is MIME-inspected in
5122 order to classify the
5125 .Ql Content-Transfer-Encoding:
5128 that is required to send this part over mail transport, i.e.,
5129 a computation rather similar to what the
5131 command produces when used with the
5135 This classification however treats text files which are encoded in
5136 UTF-16 (seen for HTML files) and similar character sets as binary
5137 octet-streams, forcefully changing any
5142 .Ql application/octet-stream :
5143 If that actually happens a yet unset charset MIME parameter is set to
5145 effectively making it impossible for the receiving MUA to automatically
5146 interpret the contents of the part.
5148 If this option is set, and the data was unambiguously identified as text
5149 data at first glance (by a
5153 file extension), then the original
5155 will not be overwritten.
5158 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
5159 \*(IN \*(OP Used to control usage of the users
5161 file for lookup of account credentials, as documented in the section
5162 .Sx "On URL syntax and credential lookup"
5166 .Sx "The .netrc file"
5167 documents the file format.
5171 Causes the filename given in the
5174 and the sender-based filenames for the
5178 commands to be interpreted relative to the directory given in the
5180 variable rather than to the current directory,
5181 unless it is set to an absolute pathname.
5185 If set, each message the
5187 command prints out is followed by a formfeed character
5192 Send messages to the
5194 command without performing MIME and character set conversions.
5197 .Mx Va pop3-bulk-load
5198 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
5199 \*(OP When accessing a POP3 server \*(UA loads the headers of the
5200 messages, and only requests the message bodies on user request.
5201 For the POP3 protocol this means that the message headers will be
5203 If this option is set then \*(UA will download only complete messages
5204 from the given POP3 server(s) instead.
5207 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
5208 \*(OP Unless this variable is set the
5210 authentication method will be used when connecting to a POP3 server that
5214 is that the password is not sent in clear text over the wire and that
5215 only a single packet is sent for the user/password tuple.
5217 .Va pop3-no-apop-HOST
5220 .Mx Va pop3-use-starttls
5221 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
5222 \*(OP Causes \*(UA to issue a
5224 command to make an unencrypted POP3 session SSL/TLS encrypted.
5225 This functionality is not supported by all servers,
5226 and is not used if the session is already encrypted by the POP3S method.
5228 .Va pop3-use-starttls-HOST
5232 .It Va print-all-chars
5233 This option causes all characters to be considered printable.
5234 It is only effective if given in a startup file.
5235 With this option set some character sequences in messages may put the
5236 user's terminal in an undefined state when printed;
5237 it should only be used as a last resort if no working system locale can
5241 .It Va print-alternatives
5242 When a MIME message part of type
5243 .Ql multipart/alternative
5244 is displayed and it contains a subpart of type
5246 other parts are normally discarded.
5247 Setting this variable causes all subparts to be displayed,
5248 just as if the surrounding part was of type
5249 .Ql multipart/mixed .
5253 Suppresses the printing of the version when first invoked.
5256 .It Va quote-as-attachment
5257 If this is set, then the original message is added in its entirety as a
5259 MIME attachment when replying to a message.
5260 Note this works regardless of the setting of
5264 .It Va recipients-in-cc
5265 On group replies, specify only the sender of the original mail in
5267 and mention the other recipients in the secondary
5269 By default all recipients of the original mail will be addressed via
5273 .It Va record-resent
5274 If both this variable and the
5281 commands save messages to the
5283 folder as it is normally only done for newly composed messages.
5286 .It Va reply-in-same-charset
5287 If this variable is set \*(UA first tries to use the same character set
5288 of the original message for replies.
5289 If this fails, the mechanism described in
5290 .Sx "Character sets"
5291 is evaluated as usual.
5294 .It Va rfc822-body-from_
5295 This variable can be used to force displaying a so-called
5297 line for messages that are embedded into an envelope mail via the
5299 MIME mechanism, for more visual convenience.
5303 Enable saving of (partial) messages in
5305 upon interrupt or delivery error.
5308 .It Va searchheaders
5309 Expand message-list specifiers in the form
5311 to all messages containing the substring
5315 The string search is case insensitive.
5318 .It Va sendcharsets-else-ttycharset
5319 \*(OP If this variable is set, but
5321 is not, then \*(UA acts as if
5323 had been set to the value of the variable
5325 In effect this combination passes through the message data in the
5326 character set of the current locale (given that
5328 hasn't been set manually), i.e., without converting it to the
5330 fallback character set.
5331 Thus, mail message text will be in ISO-8859-1 encoding when send from
5332 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
5334 If no character set conversion capabilities are available in \*(UA then
5335 the only supported character set is
5338 .It Va sendmail-no-default-arguments
5339 Unless this option is set \*(UA will pass some well known
5340 standard command line options to the defined
5342 program, see there for more.
5346 When sending a message wait until the MTA (including the builtin SMTP
5347 one) exits before accepting further commands.
5349 with this variable set errors reported by the MTA will be recognizable!
5350 If the MTA returns a non-zero exit status,
5351 the exit status of \*(ua will also be non-zero.
5355 Setting this option causes \*(UA to start at the last message instead of
5356 the first one when opening a mail folder.
5360 Causes \*(UA to use the sender's real name instead of the plain address
5361 in the header field summary and in message specifications.
5365 Causes the recipient of the message to be shown in the header summary
5366 if the message was sent by the user.
5369 .It Va skipemptybody
5370 If an outgoing message does not contain any text in its first or only
5372 do not send it but discard it silently (see also the command line option
5376 .It Va smime-force-encryption
5377 \*(OP Causes \*(UA to refuse sending unencrypted messages.
5381 \*(OP S/MIME sign outgoing messages with the user's private key and
5382 include the user's certificate as a MIME attachment.
5383 Signing a message enables a recipient to verify that the sender used
5384 a valid certificate,
5385 that the email addresses in the certificate match those in the message
5386 header and that the message content has not been altered.
5387 It does not change the message text,
5388 and people will be able to read the message as usual.
5390 .Va smime-sign-cert , smime-sign-include-certs
5392 .Va smime-sign-message-digest .
5395 .It Va smime-no-default-ca
5396 \*(OP Don't load default CA locations when verifying S/MIME signed
5399 .Mx Va smtp-use-starttls
5400 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
5401 \*(OP Causes \*(UA to issue a
5403 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
5404 transport layer security.
5407 .It Va ssl-no-default-ca
5408 \*(OP Don't load default CA locations to verify SSL/TLS server
5413 \*(OP If terminal capability queries are supported and this option is
5414 set then \*(UA will try to switch to the
5415 .Dq alternate screen
5416 when in interactive mode, so that the terminal will go back to the
5417 normal screen, leaving all the text there intact, when \*(UA exits.
5419 even when supported for this to produce appealing results the used
5421 and possibly configured
5422 .Va pipe-TYPE/SUBTYPE
5423 applications that take control over the terminal need to have
5424 corresponding support too, e.g., the
5426 pager should be driven with the
5431 .It Va keep-content-length
5432 When (editing messages and) writing
5434 mailbox files \*(UA can be told to keep the
5438 header fields that some MUAs generate by setting this variable.
5439 Since \*(UA does neither use nor update these non-standardized header
5440 fields (which in itself shows one of their conceptual problems),
5441 stripping them should increase interoperability in between MUAs that
5442 work with with same mailbox files.
5443 Note that, if this is not set but
5444 .Va writebackedited ,
5445 as below, is, a possibly performed automatic stripping of these header
5446 fields already marks the message as being modified.
5450 Setting this option enables upward compatibility with \*(UA version 15.0
5451 in respect to which configuration options are available and how they are
5453 This manual uses \*(IN and \*(OU to refer to the new and the old way of
5454 doing things, respectively.
5458 Setting this option, also controllable via the command line option
5460 causes \*(UA to be more verbose, so that, e.g., certificate chains will
5461 be displayed on the users terminal.
5462 Setting this binary option twice increases the level of verbosity, in
5463 which case even details of the actual message delivery and protocol
5464 conversations are shown.
5467 is sufficient to disable verbosity as such.
5470 .It Va writebackedited
5471 If this variable is set messages modified using the
5475 commands are written back to the current folder when it is quit;
5476 it is only honoured for writable folders in MBOX format, though.
5477 Note that the editor will be pointed to the raw message content in that
5478 case, i.e., neither MIME decoding nor decryption will have been
5479 performed, and proper RFC 4155
5481 quoting of newly added or edited content is also left as an excercise to
5486 .\" .Ss "Value options" {{{
5489 Options with values that are generally treated as strings.
5490 To embed whitespace (space and tabulator) in a value it either needs to
5491 be escaped with a backslash character, or the entire value must be
5492 enclosed in (double or single) quotation marks;
5493 To use quotation marks identical to those used to enclose the value,
5494 escape them with a backslash character.
5495 The backslash character has no special meaning except in these cases.
5497 .Bd -literal -offset indent
5498 set 1=val\e one 2="val two" 3='val "three"' 4='val \e'four\e''
5504 Booleans are special string values that must either be set to decimal
5505 integers (in which case
5509 and any other value is true) or to any of
5514 for a false boolean and
5519 for a true boolean; matching is performed case-insensitively.
5520 And there exists a special kind of boolean, the
5522 this is expected to either name a boolean or one of the strings
5528 followed by a valid boolean, case-insensitively);
5529 if one of the latter is set then in interactive mode the user will be
5530 prompted with the default value (also used for empty user input) set to
5531 the given boolean, whereas in non-interactive the given default will
5534 .Bl -tag -width ".It Va _utoprin_"
5535 .Mx Va agent-shell-lookup
5536 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5538 \*(IN \*(OP Account passwords can be fetched via an external agent
5539 program in order to permit encrypted password storage \(en see
5540 .Sx "On URL syntax and credential lookup"
5541 for more on credential lookup.
5542 If this is set then the content is interpreted as a shell command the
5543 output of which (with newline characters removed) is treated as the
5544 account password shall the command succeed (and have produced non-empty
5545 non-newline output); e.g., via
5547 .Bd -literal -offset indent
5548 $ echo PASSWORD > .pass
5550 $ eval `gpg-agent --daemon \e
5551 --pinentry-program=/usr/bin/pinentry-curses \e
5552 --max-cache-ttl 99999 --default-cache-ttl 99999`
5553 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5557 A couple of environment variables will be set for the agent:
5559 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5561 The temporary directory that \*(UA uses.
5562 Usually identical to
5564 but guaranteed to be set and usable by child processes;
5565 to ensure the latter condition for
5571 for which the password is looked up.
5572 .It Ev NAIL_USER_ENC
5573 The URL percent-encoded variant of
5576 The plain machine hostname of the user account.
5577 .It Ev NAIL_HOST_PORT
5580 (hostname possibly including port) of the user account.
5585 A sequence of characters to print in the
5589 as shown in the header display; each for one type of messages (see
5590 .Sx "Message states" ) ,
5591 with the default being
5594 .Ql NU\ \ *HMFAT+\-$~
5599 environment variable are set, in the following order:
5601 .Bl -tag -compact -offset indent -width ".It Ql _"
5623 start of a collapsed thread.
5629 classified as possible spam.
5634 Specifies a list of recipients to which a blind carbon copy of each
5635 outgoing message will be sent automatically.
5639 Specifies a list of recipients to which a carbon copy of each outgoing
5640 message will be sent automatically.
5644 Causes sorted mode (see the
5646 command) to be entered automatically with the value of this option as
5647 sorting method when a folder is opened.
5651 The value that should appear in the
5655 MIME header fields when no character set conversion of the message data
5657 This defaults to US-ASCII, and the chosen character set should be
5658 US-ASCII compatible.
5662 \*(OP The default 8-bit character set that is used as an implicit last
5663 member of the variable
5665 This defaults to UTF-8.
5666 If no character set conversion capabilities are available in \*(UA then
5667 the only supported character set is
5669 Refer to the section
5670 .Sx "Character sets"
5671 for the complete picture of character set conversion in \*(UA.
5674 .It Va charset-unknown-8bit
5675 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5677 the content of a mail message by using a character set with the name
5679 Because of the unclassified nature of this character set \*(UA will not
5680 be capable to convert this character set to any other character set.
5681 If this variable is set any message part which uses the character set
5683 is assumed to really be in the character set given in the value,
5684 otherwise the (final) value of
5686 is used for this purpose.
5690 The default value for the
5696 \*(OP The colour specification for so-called
5700 .Sx "Coloured message display"
5701 for the format of the value.
5704 .It Va colour-header
5705 \*(OP The colour specification for header lines.
5708 .It Va colour-msginfo
5709 \*(OP The colour specification for the introductional message info line.
5712 .It Va colour-partinfo
5713 \*(OP The colour specification for MIME part info lines.
5717 \*(OP A comma-separated list of
5719 inals for which coloured message display can be used.
5720 Entries only need to be added if the string
5722 isn't part of the terminal name itself; the default value is
5724 .Dl cons25,linux,rxvt,rxvt-unicode,\:screen,\:sun,\:vt100,\:vt220,\:\
5728 .It Va colour-uheader
5729 \*(OP The colour specification for those header lines that have been
5731 .Va colour-user-headers
5734 .Sx "Coloured message display" .
5737 .It Va colour-user-headers
5738 A comma separated list of (case-insensitive) header names which should
5739 be colourized with the alternative
5742 The default value is
5747 In a(n interactive) terminal session, then if this valued option is set
5748 it'll be used as a threshold to determine how many lines the given
5749 output has to span before it will be displayed via the configured
5753 can be forced by setting this to the value
5755 setting it without a value will deduce the current height of the
5756 terminal screen to compute the treshold (see
5763 The date in a header summary is normally the date of the mailbox
5765 line of the message.
5766 If this variable is set, then the date as given in the
5768 field is used, converted to local time.
5769 It is possible to control the display of the date by assigning a value,
5772 function will be used to format the date accordingly.
5773 Please read your system manual for the available formats.
5776 format should not be used, because \*(UA doesn't take embedded newlines
5777 into account when calculating how many lines fit onto the screen.
5780 .It Va datefield-markout-older
5781 This option, when set in addition to
5785 messages (concept is rather comparable to the
5787 option of the POSIX utility
5789 The content interpretation is identical to
5794 Suggestion for the MIME encoding to use in outgoing text messages
5796 Valid values are the default
5797 .Ql quoted-printable ,
5802 may cause problems when transferring mail messages over channels that
5803 are not ESMTP (RFC 1869) compliant.
5804 If there is no need to encode a message,
5806 transfer mode is always used regardless of this variable.
5807 Binary data is always encoded as
5812 If defined, the first character of this option
5813 gives the character to use in place of
5816 .Sx "TILDE ESCAPES" .
5820 If not set then file and command pipeline targets are not allowed,
5821 and any such address will be filtered out, giving a warning message.
5822 If set without a value then all possible recipient address
5823 specifications will be accepted \(en see the section
5826 To accept them, but only in interactive mode, or when tilde commands
5827 were enabled explicitly by using one of the command line options
5831 set this to the (case-insensitive) value
5833 (note right now this is actually like setting
5834 .Ql restrict,-all,+name,+addr ) .
5836 In fact the value is interpreted as a comma-separated list of values.
5839 then the existence of disallowed specifications is treated as a hard
5840 send error instead of only filtering them out.
5841 The remaining values specify whether a specific type of recipient
5842 address specification is allowed (optionally indicated by a plus sign
5844 prefix) or disallowed (prefixed with a hyphen
5848 addresses all possible address specifications,
5852 command pipeline targets,
5854 plain user names and (MTA) aliases (\*(OB
5856 may be used as an alternative syntax to
5861 These kind of values are interpreted in the given order, so that
5862 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5863 will cause hard errors for any non-network address recipient address
5864 unless \*(UA is in interactive mode or has been started with the
5868 command line option; in the latter case(s) any address may be used, then.
5872 Unless this variable is set additional mail-transfer-agent (MTA)
5873 arguments from the command line, as can be given after a
5875 separator, are ignored due to safety reasons.
5876 However, if set to the special value
5878 then the presence of additional MTA arguments is treated as a hard
5879 error that causes \*(UA to exit with failure status.
5880 A lesser strict variant is the otherwise identical
5882 which does accept such arguments in interactive mode, or if tilde
5883 commands were enabled explicitly by using one of the command line options
5890 \*(RO Information on the features compiled into \*(UA \(en the content
5891 of this variable is identical to the output of the command
5896 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5897 It is possible to install file hooks which will be used by the
5899 command in order to be able to transparently handle (through an
5900 intermediate temporary file) files with specific
5902 s: the variable values can include shell snippets and are expected to
5903 write data to standard output / read data from standard input,
5905 \*(ID The variables may not be changed while there is a mailbox
5907 .Bd -literal -offset indent
5908 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5909 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5910 record=+null-sent.xy
5915 The name of the directory to use for storing folders of messages.
5916 All folder names that begin with
5918 refer to files below it.
5919 The same special conventions as documented for the
5921 command may be used when specifying a new value for
5923 but be aware that the expansion is fully performed immediately.
5924 E.g., if the expanded name refers to an IMAP account, all names that
5925 begin with `+' refer to IMAP mailboxes below the
5929 Note: for IMAP it makes a difference whether
5931 ends with a directory separator solidus or not in respect to the
5932 automatic append of `INBOX' strings.
5933 Ssome IMAP servers do not accept the creation of mailboxes in
5934 the hierarchy base, but require that they are created as subfolders of
5935 `INBOX' \(en with such servers a folder name of the form
5937 .Dl imaps://mylogin@imap.myisp.example/INBOX.
5939 should be used (the last character is the server's hierarchy delimiter).
5940 Folder names prefixed by `+' will then refer to folders below `INBOX',
5941 while folder names prefixed by `@' refer to folders below the hierarchy
5945 namespace command for a method to detect the appropriate prefix and
5950 When a folder is opened and this variable is set,
5951 the macro corresponding to the value of this variable is executed.
5952 The macro is also invoked when new mail arrives,
5953 but message lists for commands executed from the macro
5954 only include newly arrived messages then.
5957 are activated in a folder hook, then the covered settings will be
5958 reverted once the folder is left again.
5961 .It Va folder-hook-FOLDER
5966 Unlike other folder specifications, the fully expanded name of a folder,
5967 without metacharacters, is used to avoid ambiguities.
5968 However, if the mailbox resides under
5972 specification is tried in addition, e.g., if
5976 (and thus relative to the user's home directory) then
5977 .Pa /home/usr1/mail/sent
5979 .Ql folder-hook-/home/usr1/mail/sent
5980 first, but then followed by
5981 .Ql folder-hook-+sent .
5984 .It Va followup-to-honour
5986 .Ql Mail-Followup-To:
5987 header is honoured when group-replying to a message via
5991 This is a quadoption; if set without a value it defaults to
6002 The address (or a list of addresses) to put into the
6004 field of the message header, quoting RFC 5322:
6005 the author(s) of the message, that is, the mailbox(es) of the person(s)
6006 or system(s) responsible for the writing of the message.
6007 If replying to messages these addresses are handled as if they were in
6011 If the machine's hostname is not valid at the Internet (for example at
6012 a dialup machine) then either this variable or
6017 adds even more fine-tuning capabilities),
6021 contains more than one address,
6024 variable is required (according to the standard RFC 5322).
6028 The string to print before the text of a message with the
6032 .Va forward-as-attachment
6035 .Dq -------- Original Message --------
6036 if unset; No heading is printed if it is set to the empty string.
6040 A format string to use for the header summary,
6046 introduces a format specifier that may be followed by a number
6047 indicating the field width;
6048 If the (possibly implicitly implied) field width is negative, the field
6049 is to be left-aligned.
6050 Valid format specifiers are:
6052 .Bl -tag -compact -offset indent -width "_%%_"
6054 A plain percent character.
6056 A space character but for the current message, for which it expands to
6059 A space character but for the current message, for which it expands to
6062 \*(OP The spam score of the message, as has been classified via the
6065 Prints only a replacement character if there is no spam support.
6067 Message attribute character (status flag); the actual content can be
6071 The date when the message was received.
6073 The indenting level in threaded mode.
6075 The address of the message sender.
6077 The message thread structure.
6078 (Note that this format doesn't support a field width.)
6080 The number of lines of the message.
6084 The number of octets (bytes) in the message.
6086 Message subject (if any).
6088 Message subject (if any) in double quotes.
6090 Message recipient flags: is the addressee of the message a known or
6091 subscribed mailing list \(en see
6096 The position in threaded/sorted order.
6100 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
6102 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
6112 .It Va headline-bidi
6113 Bidirectional text requires special treatment when displaying headers,
6114 because numbers (in dates or for file sizes etc.) will not affect the
6115 current text direction, in effect resulting in ugly line layouts when
6116 arabic or other right-to-left text is to be displayed.
6117 On the other hand only a minority of terminals is capable to correctly
6118 handle direction changes, so that user interaction is necessary for
6120 Note that extended host system support is required nonetheless, e.g.,
6121 detection of the terminal character set is one precondition;
6122 and this feature only works in an Unicode (i.e., UTF-8) locale.
6124 In general setting this variable will cause \*(UA to encapsulate text
6125 fields that may occur when printing
6127 (and some other fields, like dynamic expansions in
6129 with special Unicode control sequences;
6130 it is possible to fine-tune the terminal support level by assigning
6132 no value (or any value other than
6137 will make \*(UA assume that the terminal is capable to properly deal
6138 with Unicode version 6.3, in which case text is embedded in a pair of
6139 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6141 In addition no space on the line is reserved for these characters.
6143 Weaker support is chosen by using the value
6145 (Unicode 6.3, but reserve the room of two spaces for writing the control
6146 sequences onto the line).
6151 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6152 again reserves room for two spaces in addition.
6156 Use this string as hostname when expanding local addresses instead of
6157 the value obtained from
6168 transport is not used then it is normally the responsibility of the MTA
6169 to create these fields, \*(IN in conjunction with
6173 also influences the results;
6174 you should produce some test messages with the desired combination of
6182 .It Va imap-auth-USER@HOST , imap-auth
6183 \*(OP Sets the IMAP authentication method.
6184 Valid values are `login' for the usual password-based authentication
6186 `cram-md5', which is a password-based authentication that does not send
6187 the password over the network in clear text,
6188 and `gssapi' for GSS-API based authentication.
6192 \*(OP Enables caching of IMAP mailboxes.
6193 The value of this variable must point to a directory that is either
6194 existent or can be created by \*(UA.
6195 All contents of the cache can be deleted by \*(UA at any time;
6196 it is not safe to make assumptions about them.
6198 .Mx Va imap-keepalive
6199 .It Va imap-keepalive-USER@HOST , imap-keepalive-HOST , imap-keepalive
6200 \*(OP IMAP servers may close the connection after a period of
6201 inactivity; the standard requires this to be at least 30 minutes,
6202 but practical experience may vary.
6203 Setting this variable to a numeric `value' greater than 0 causes
6204 a `NOOP' command to be sent each `value' seconds if no other operation
6208 .It Va imap-list-depth
6209 \*(OP When retrieving the list of folders on an IMAP server, the
6211 command stops after it has reached a certain depth to avoid possible
6213 The value of this variable sets the maximum depth allowed.
6215 If the folder separator on the current IMAP server is a slash `/',
6216 this variable has no effect and the
6218 command does not descend to subfolders.
6222 If this is set it will be used for expansions of
6227 The value supports a subset of filename expansions itself.
6238 option for indenting messages,
6239 in place of the normal tabulator character
6241 which is the default.
6242 Be sure to quote the value if it contains spaces or tabs.
6245 .It Va line-editor-cursor-right
6246 \*(OP If the builtin command line editor is used, actions which are
6247 based on rightwise movement may not work on some terminals.
6248 If you encounter such problems, set this variable to the terminal
6249 control sequence that is necessary to move the cursor one column to the
6253 which should work for most terminals.
6260 and other control character have to be written as shell-style escape
6268 Is used as the user's mailbox, if set.
6269 Otherwise, a system-dependent default is used.
6270 Supports a logical subset of the special conventions that are documented
6278 .It Va mime-counter-evidence
6281 field is used to decide how to handle MIME parts.
6282 Some MUAs however don't use
6284 or a similar mechanism to correctly classify content, but simply specify
6285 .Ql application/octet-stream ,
6286 even for plain text attachments like
6288 If this variable is set then \*(UA will try to classify such MIME
6289 message parts on its own, if possible, and through their file name.
6290 This variable can also be given a non-empty value, in which case the
6291 value is expected to be a number, actually a carrier of bits.
6292 Creating the bit-carrying number is a simple addition:
6293 .Bd -literal -offset indent
6294 ? !echo Value should be set to $((2 + 4))
6295 Value should be set to 6
6298 .Bl -bullet -compact
6300 If bit two is set (2) then the detected
6302 content-type will be carried along with the message and be used for
6304 .Va pipe-TYPE/SUBTYPE
6305 is responsible for the MIME part, shall that question arise;
6306 when displaying such a MIME part the part-info will indicate the
6307 overridden content-type by showing a plus-sign
6310 If bit three is set (4) then the counter-evidence is always produced
6311 and a positive result will be used as the MIME type, even forcefully
6312 overriding the parts given MIME type.
6314 .\"If bit four is set (8) then as a last resort the content of
6315 .\".Ql application/octet-stream
6316 .\"parts will be inspected, so that data that looks like (english) plain
6317 .\"text can be treated as such.
6321 .It Va mimetypes-load-control
6322 This option can be used to control which of the
6324 databases are loaded by \*(UA, as furtherly described in the section
6325 .Sx "The mime.types files" .
6328 is part of the option value, then the user's personal
6330 file will be loaded (if it exists); likewise the letter
6332 controls loading of the system wide
6333 .Pa /etc/mime.types ;
6334 the user file is loaded first, letter matching is case-insensitive.
6335 If this option is not set \*(UA will try to load both files instead.
6336 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6337 but they will be matched last.
6339 More sources can be specified by using a different syntax: if the
6340 value string contains an equals sign
6342 then it is instead parsed as a comma-separated list of the described
6345 pairs; the given filenames will be expanded and loaded, and their
6346 content may use the extended syntax that is described in the section
6347 .Sx "The mime.types files" .
6350 .It Va NAIL_EXTRA_RC
6351 The name of an optional startup file to be read after
6353 This variable has an effect only if it is set in
6357 it is not imported from the environment in order to honour
6358 .Ql MAILRC=/dev/null Ns /
6361 Use this file for commands that are not understood by other POSIX
6367 A string to put at the beginning of each new message.
6368 The escape sequences tabulator
6375 .It Va NAIL_HISTFILE
6376 \*(OP If a command line editor is available then this can be set to
6377 name the (expandable) path of the location of a permanent history file.
6380 .It Va NAIL_HISTSIZE
6381 \*(OP If a command line editor is available this value restricts the
6382 amount of history entries that are saved into a set and valid
6384 A value of less than 0 disables this feature;
6385 note that loading and incorporation of
6387 upon program startup can also be suppressed by doing this.
6388 An unset or invalid value, or 0, causes a default value to be used.
6389 Dependent on the available command line editor this will also define the
6390 number of history entries in memory;
6391 it is also editor-specific whether runtime updates of this value will be
6396 A string to put at the end of each new message.
6397 The escape sequences tabulator
6405 If this variable has the value
6407 newly created local folders will be in Maildir format.
6411 Checks for new mail in the current folder each time the prompt is
6413 For IMAP mailboxes the server is then polled for new mail,
6414 which may result in delayed operation if the connection to the server is
6416 A Maildir folder must be re-scanned to determine if new mail has arrived.
6418 If this variable is set to the special value
6420 an IMAP server is not actively asked for new mail, but new mail may
6421 still be detected and announced with any other IMAP command that is sent
6423 In either case the IMAP server may send notifications about messages
6424 that have been deleted on the server by another process or client.
6426 .Dq Expunged X messages
6427 is printed regardless of this variable, and message numbers may have
6430 If this variable is set to the special value
6432 then a Maildir folder will not be rescanned completely, but only
6433 timestamp changes are detected.
6437 The value to put into the
6439 field of the message header.
6442 .It Va password-USER@HOST , password-HOST , password
6443 \*(IN Variable chain that sets a password, which is used in case none has
6444 been given in the protocol and account-specific URL;
6445 as a last resort \*(UA will ask for a password on the user's terminal if
6446 the authentication method requires a password.
6447 Specifying passwords in a startup file is generally a security risk;
6448 the file should be readable by the invoking user only.
6450 .It Va password-USER@HOST
6451 \*(OU (see the chain above for \*(IN)
6452 Set the password for
6456 If no such variable is defined for a host,
6457 the user will be asked for a password on standard input.
6458 Specifying passwords in a startup file is generally a security risk;
6459 the file should be readable by the invoking user only.
6462 .It Va pipe-TYPE/SUBTYPE
6463 When a MIME message part of type
6465 (normalized to lowercase) is displayed or quoted,
6466 its text is filtered through the value of this variable interpreted as
6470 can be used to force interpretation of the message part as plain text, e.g.,
6471 .Ql set pipe-application/pgp-signature=@
6472 will henceforth treat signatures as plain text and display them "as is".
6473 (The same can also be achieved, in a more useful context, by using the
6475 command in conjunction with a type marker.)
6477 Also, if a shell command is prefixed with
6479 then the command will only be used to prepare the MIME message part if
6480 the message is displayed by itself, but not when multiple messages are
6483 Finally, if a shell command is prefixed with
6485 then, in addition to what has been described for the plain
6487 shell command prefix, the command will be run asynchronously, i.e.,
6488 without blocking \*(UA, which may be a handy way to display a, e.g., PDF
6489 file while also continuing to read the mail message.
6490 Some information about the MIME part to be displayed is embedded into
6491 the environment of the shell command:
6493 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6496 The temporary directory that \*(UA uses.
6497 Usually identical to
6499 but guaranteed to be set and usable by child processes;
6500 to ensure the latter condition for
6504 .It Ev NAIL_FILENAME
6505 The filename, if any is set, the empty string otherwise.
6507 .It Ev NAIL_FILENAME_GENERATED
6511 The MIME content-type of the part, if known, the empty string otherwise.
6513 .It Ev NAIL_CONTENT_EVIDENCE
6515 .Va mime-counter-evidence
6516 includes the carry-around-bit (2), then this will be set to the detected
6517 MIME content-type; not only then identical to
6518 .Ev \&\&NAIL_CONTENT
6523 .It Va pipe-EXTENSION
6524 This is identical to
6525 .Va pipe-TYPE/SUBTYPE
6528 (normalized to lowercase using character mappings of the ASCII charset)
6529 names a file extension, e.g.,
6531 Handlers registered using this method take precedence.
6533 .Mx Va pop3-keepalive
6534 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6535 \*(OP POP3 servers close the connection after a period of inactivity;
6536 the standard requires this to be at least 10 minutes,
6537 but practical experience may vary.
6538 Setting this variable to a numeric value greater than
6542 command to be sent each value seconds if no other operation is performed.
6546 The string printed when a command is accepted.
6547 Prompting may be prevented by either setting this to the null string
6550 The same XSI escape sequences that are understood by the
6552 command may be used within
6555 In addition, the following \*(UA specific additional sequences are
6562 is set, in which case it expands to
6566 is the default value of
6569 which will expand to
6571 if the last command failed and to
6575 which will expand to the name of the currently active
6577 if any, and to the empty string otherwise, and
6579 which will expand to the name of the currently active mailbox.
6580 (Note that the prompt buffer is size-limited, excess is cut off.)
6586 to encapsulate the expansions of the
6590 escape sequences as necessary to correctly display bidirectional text,
6591 this is not true for the final string that makes up
6593 as such, i.e., real BIDI handling is not supported.
6595 When a newer version of the
6597 .Sx "Command line editor"
6598 is used, any escape sequence must itself be encapsulated with another
6599 escape character for usage with the
6601 mechanism: \*(UA configures the control character
6607 If set, \*(UA starts a replying message with the original message
6608 prefixed by the value of the variable
6610 Normally, a heading consisting of
6611 .Dq Fromheaderfield wrote:
6612 is printed before the quotation.
6617 variable, this heading is omitted.
6620 is assigned, the headers selected by the
6621 .Ic ignore Ns / Ns Ic retain
6622 commands are printed above the message body,
6625 acts like an automatic
6631 is assigned, all headers are printed above the message body and all MIME
6632 parts are included, making
6634 act like an automatic
6637 .Va quote-as-attachment .
6641 \*(OP Can be set in addition to
6643 Setting this turns on a more fancy quotation algorithm in that leading
6644 quotation characters are compressed and overlong lines are folded.
6646 can be set to either one or two (space separated) numeric values,
6647 which are interpreted as the maximum (goal) and the minimum line length,
6648 respectively, in a spirit rather equal to the
6650 program, but line-, not paragraph-based.
6651 If not set explicitly the minimum will reflect the goal algorithmically.
6652 The goal can't be smaller than the length of
6654 plus some additional pad.
6655 Necessary adjustments take place silently.
6659 If defined, gives the pathname of the folder used to record all outgoing
6661 If not defined, then outgoing mail is not saved.
6662 When saving to this folder fails the message is not sent,
6663 but instead saved to
6667 .It Va reply_strings
6668 Can be set to a comma-separated list of (case-insensitive according to
6669 ASCII rules) strings which shall be recognized in addition to the
6672 reply message indicators \(en builtin are
6674 which is mandated by RFC 5322, as well as the german
6679 A list of addresses to put into the
6681 field of the message header.
6682 Members of this list are handled as if they were in the
6687 .It Va reply-to-honour
6690 header is honoured when replying to a message via
6694 This is a quadoption; if set without a value it defaults to
6699 When \*(UA initially prints the message headers it determines the number
6700 to print by looking at the speed of the terminal.
6701 The faster the terminal, the more it prints.
6702 This option overrides this calculation and specifies how many message
6703 headers are printed.
6704 This number is also used for scrolling with the
6710 \*(OP A comma-separated list of character set names that can be used in
6711 outgoing internet mail.
6712 The value of the variable
6714 is automatically appended to this list of character-sets.
6715 If no character set conversion capabilities are compiled into \*(UA then
6716 the only supported charset is
6719 .Va sendcharsets-else-ttycharset
6720 and refer to the section
6721 .Sx "Character sets"
6722 for the complete picture of character set conversion in \*(UA.
6726 An address that is put into the
6728 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6729 responsible for the actual transmission of the message.
6730 This field should normally not be used unless the
6732 field contains more than one address, on which case it is required.
6735 address is handled as if it were in the
6741 To use an alternate mail transport agent (MTA),
6742 set this option to the full pathname of the program to use.
6743 It may be necessary to set
6744 .Va sendmail-progname
6747 The MTA will be passed command line arguments from several possible
6748 sources: from the variable
6749 .Va sendmail-arguments
6750 if set, from the command line if given and the variable
6753 Argument processing of the MTA will be terminated with a
6757 The otherwise occurring implicit usage of the following MTA command line
6758 arguments can be disabled by setting the boolean option
6759 .Va sendmail-no-default-arguments
6760 (which will also disable passing
6764 (for not treating a line with only a dot
6766 character as the end of input),
6774 option is set); in conjunction with the
6776 command line option \*(UA will also pass
6782 .It Va sendmail-arguments
6783 Arguments to pass through to the Mail-Transfer-Agent can be given via
6785 The content of this variable will be split up in a vector of arguments
6786 which will be joined onto other possible MTA options:
6788 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
6791 .It Va sendmail-no-default-arguments
6792 \*(BY Unless this option is set \*(UA will pass some well known
6793 standard command line options to the defined
6795 program, see there for more.
6798 .It Va sendmail-progname
6799 Many systems use a so-called
6801 environment to ensure compatibility with
6803 This works by inspecting the name that was used to invoke the mail
6805 If this variable is set then the mailwrapper (the program that is
6806 actually executed when calling
6808 will treat its contents as that name.
6814 A string for use with the
6820 A string for use with the
6826 Must correspond to the name of a readable file if set.
6827 The file's content is then appended to each singlepart message
6828 and to the first part of each multipart message.
6829 Be warned that there is no possibility to edit the signature for an
6834 \*(OP Specifies a directory with CA certificates in PEM (Privacy
6835 Enhanced Mail) format for verification of S/MIME signed messages.
6838 .It Va smime-ca-file
6839 \*(OP Specifies a file with CA certificates in PEM format for
6840 verification of S/MIME signed messages.
6843 .It Va smime-cipher-USER@HOST , smime-cipher
6844 \*(OP Specifies the cipher to use when generating S/MIME encrypted
6845 messages (for the specified account).
6846 RFC 5751 mandates a default of
6849 Possible values are (case-insensitive and) in decreasing cipher strength:
6857 (DES EDE3 CBC, 168 bits; default if
6859 isn't available) and
6863 The actually available cipher algorithms depend on the cryptographic
6864 library that \*(UA uses.
6865 \*(OP Support for more cipher algorithms may be available through
6866 dynamic loading via, e.g.,
6867 .Xr EVP_get_cipherbyname 3
6868 (OpenSSL) if \*(UA has been compiled to support this.
6871 .It Va smime-crl-dir
6872 \*(OP Specifies a directory that contains files with CRLs in PEM format
6873 to use when verifying S/MIME messages.
6876 .It Va smime-crl-file
6877 \*(OP Specifies a file that contains a CRL in PEM format to use when
6878 verifying S/MIME messages.
6881 .It Va smime-encrypt-USER@HOST
6882 \*(OP If this variable is set, messages send to the given receiver are
6883 encrypted before sending.
6884 The value of the variable must be set to the name of a file that
6885 contains a certificate in PEM format.
6887 If a message is sent to multiple recipients,
6888 each of them for whom a corresponding variable is set will receive an
6889 individually encrypted message;
6890 other recipients will continue to receive the message in plain text
6892 .Va smime-force-encryption
6894 It is recommended to sign encrypted messages, i.e., to also set the
6898 .Mx Va smime-sign-cert
6899 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
6900 \*(OP Points to a file in PEM format.
6901 For the purpose of signing and decryption this file needs to contain the
6902 user's private key as well as his certificate.
6906 is always derived from the value of
6908 (or, if that contains multiple addresses,
6910 For the purpose of encryption the recipient's public encryption key
6911 (certificate) is expected; the command
6913 can be used to save certificates of signed messages (the section
6914 .Sx "Signed and encrypted messages with S/MIME"
6915 gives some details).
6916 This mode of operation is usually driven by the specialized form.
6918 When decrypting messages the account is derived from the recipient
6923 of the message, which are searched for addresses for which such
6925 \*(UA always uses the first address that matches,
6926 so if the same message is sent to more than one of the user's addresses
6927 using different encryption keys, decryption might fail.
6929 .Mx Va smime-sign-include-certs
6930 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
6931 \*(OP If used, this is supposed to a consist of a comma-separated list
6932 of files, each of which containing a single certificate in PEM format to
6933 be included in the S/MIME message in addition to the
6936 This is most useful for long certificate chains if it is desired to aid
6937 the receiving party's verification process.
6938 Note that top level certificates may also be included in the chain but
6939 don't play a role for verification.
6941 .Va smime-sign-cert .
6942 Remember that for this
6944 refers to the variable
6946 (or, if that contains multiple addresses,
6949 .Mx Va smime-sign-message-digest
6950 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
6951 \*(OP Specifies the message digest to use when signing S/MIME messages.
6952 RFC 5751 mandates a default of
6954 Possible values are (case-insensitive and) in decreasing cipher strength:
6962 The actually available message digest algorithms depend on the
6963 cryptographic library that \*(UA uses.
6964 \*(OP Support for more message digest algorithms may be available
6965 through dynamic loading via, e.g.,
6966 .Xr EVP_get_digestbyname 3
6967 (OpenSSL) if \*(UA has been compiled to support this.
6968 Remember that for this
6970 refers to the variable
6972 (or, if that contains multiple addresses,
6977 \*(OP Normally \*(UA invokes the program defined via
6979 to transfer messages, as described in
6980 .Sx "Sending mail" .
6983 variable will instead cause SMTP network connections be made to the
6984 server specified therein in order to directly submit the message.
6985 \*(UA knows about three different
6986 .Dq SMTP protocols :
6988 .Bl -bullet -compact
6990 The plain SMTP protocol (RFC 5321) that normally lives on the
6991 server port 25 and requires setting the
6992 .Va smtp-use-starttls
6993 variable to enter a SSL/TLS encrypted session state.
6994 Assign a value like \*(IN
6995 .Ql [smtp://][user[:password]@]server[:port]
6997 .Ql [smtp://]server[:port] )
6998 to choose this protocol.
7000 Then the so-called SMTPS which is supposed to live on server port 465
7001 and is automatically SSL/TLS secured.
7002 Unfortunately it never became a standardized protocol and may thus not
7003 be supported by your hosts network service database
7004 \(en in fact the port number has already been reassigned to other
7007 SMTPS is nonetheless a commonly offered protocol and thus can be
7008 chosen by assigning a value like \*(IN
7009 .Ql smtps://[user[:password]@]server[:port]
7011 .Ql smtps://server[:port] ) ;
7012 due to the mentioned problems it is usually necessary to explicitly
7017 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7018 lives on server port 587 and is practically identically to the SMTP
7019 protocol from \*(UAs point of view beside that; it requires setting the
7020 .Va smtp-use-starttls
7021 variable to enter a SSL/TLS secured session state.
7022 Assign a value like \*(IN
7023 .Ql submission://[user[:password]@]server[:port]
7025 .Ql submission://server[:port] ) .
7028 For more on credentials etc. please see
7029 .Sx "On URL syntax and credential lookup" .
7030 The SMTP transfer is executed in a child process, which runs
7031 asynchronously unless either the
7036 If it receives a TERM signal, it will abort and save the message to
7040 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7041 \*(OP Variable chain that sets the SMTP authentication method.
7048 as well as the \*(OPal methods
7054 method doesn't need any user credentials,
7056 requires a user name and all other methods require a user name and
7064 .Va smtp-auth-password
7066 .Va smtp-auth-user ) .
7071 .Va smtp-auth-USER@HOST :
7072 may override dependend on sender address in the variable
7075 .It Va smtp-auth-password
7076 \*(OP \*(OU Sets the global fallback password for SMTP authentication.
7077 If the authentication method requires a password, but neither
7078 .Va smtp-auth-password
7080 .Va smtp-auth-password-USER@HOST
7082 \*(UA will ask for a password on the user's terminal.
7084 .It Va smtp-auth-password-USER@HOST
7086 .Va smtp-auth-password
7087 for specific values of sender addresses, dependent upon the variable
7090 .It Va smtp-auth-user
7091 \*(OP \*(OU Sets the global fallback user name for SMTP authentication.
7092 If the authentication method requires a user name, but neither
7095 .Va smtp-auth-user-USER@HOST
7097 \*(UA will ask for a user name on the user's terminal.
7099 .It Va smtp-auth-user-USER@HOST
7102 for specific values of sender addresses, dependent upon the variable
7106 .It Va smtp-hostname
7107 \*(IN Normally \*(UA uses the variable
7109 to derive the necessary
7111 information to issue a
7116 can be used to use the
7118 from the SMTP account
7125 from the content of this variable (or, if that is the empty string,
7127 or the local hostname as a last resort).
7128 This often allows using an address that is itself valid but hosted by
7129 a provider other than which (in
7131 is about to send the message.
7132 Setting this variable also influences the generated
7137 .It Va spam-interface
7138 \*(OP In order to use any of the spam-related commands (like, e.g.,
7140 the desired spam interface must be defined by setting this variable.
7141 Please refer to the manual section
7143 for the complete picture of spam handling in \*(UA.
7144 All or none of the following interfaces may be available:
7146 .Bl -tag -width ".It Ql _ilte_"
7152 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7154 Different to the generic filter interface \*(UA will automatically add
7155 the correct arguments for a given command and has the necessary
7156 knowledge to parse the program's output.
7159 will have been compiled into the \*(UA binary if
7164 Shall it be necessary to define a specific connection type (rather than
7165 using a configuration file for that), the variable
7167 can be used as in, e.g.,
7168 .Ql -d server.example.com -p 783 .
7169 It is also possible to specify a per-user configuration via
7171 Note that this interface doesn't inspect the
7173 flag of a message for the command
7177 \*(UA will directly communicate with the
7183 stream socket as specified in
7185 It is possible to specify a per-user configuration via
7189 generic spam filter support via freely configurable hooks.
7190 This interface is ment for programs like
7194 and requires according behaviour in respect to the hooks' exit
7195 status for at least the command
7198 meaning a message is spam,
7202 for unsure and any other return value indicating a hard error);
7203 since the hooks can include shell code snippets diverting behaviour
7204 can be intercepted as necessary.
7206 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7209 .Va spamfilter-spam ;
7212 contains examples for some programs.
7213 The process environment of the hooks will have the variables
7214 .Ev NAIL_TMPDIR , TMPDIR
7216 .Ev NAIL_FILENAME_GENERATED
7218 Note that spam score support for
7220 isn't supported unless the \*(OPtional regular expression support is
7222 .Va spamfilter-rate-scanscore
7229 \*(OP Messages that exceed this size won't be passed through to the
7231 .Va spam-interface .
7232 The default is 420000 bytes.
7235 .It Va spamc-command
7236 \*(OP The path to the
7240 .Va spam-interface .
7241 Note that the path is not expanded, but used
7243 A fallback path will have been compiled into the \*(UA binary if the
7244 executable had been found during compilation.
7247 .It Va spamc-arguments
7248 \*(OP Even though \*(UA deals with most arguments for the
7251 automatically, it may at least sometimes be desirable to specifiy
7252 connection-related ones via this variable, e.g.,
7253 .Ql -d server.example.com -p 783 .
7257 \*(OP Specify a username for per-user configuration files for the
7259 .Va spam-interface .
7260 If this is set to the empty string then \*(UA will use the name of the
7266 \*(OP Specify the path of the
7268 domain socket on which
7270 listens for connections for the
7272 .Va spam-interface .
7273 Note that the path is not expanded, but used
7278 \*(OP Specify a username for per-user configuration files for the
7280 .Va spam-interface .
7281 If this is set to the empty string then \*(UA will use the name of the
7290 .It Va spamfilter-ham , spamfilter-noham , \
7291 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7292 \*(OP Command and argument hooks for the
7294 .Va spam-interface .
7297 contains examples for some programs.
7300 .It Va spamfilter-rate-scanscore
7301 \*(OP Because of the generic nature of the
7304 spam scores are not supported for it by default, but if the \*(OPtional
7305 regular expression support is available then setting this variable can
7306 be used to overcome this restriction.
7307 It is interpreted as follows: first a number (digits) is parsed that
7308 must be followed by a semicolon
7310 and a regular expression.
7311 Then the latter is used to parse the first output line of the
7313 hook, and, in case the evaluation is successful, the group that has been
7314 specified via the number is interpreted as a floating point scan score.
7318 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7319 Enhanced Mail) for verification of of SSL/TLS server certificates.
7321 .Xr SSL_CTX_load_verify_locations 3
7322 for more information.
7326 \*(OP Specifies a file with CA certificates in PEM format for
7327 verification of SSL/TLS server certificates.
7329 .Xr SSL_CTX_load_verify_locations 3
7330 for more information.
7333 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7334 \*(OP Variable chain that sets the file name for a SSL/TLS client
7335 certificate required by some servers.
7336 This is a direct interface to the
7340 function of the OpenSSL library, if available.
7342 .Mx Va ssl-cipher-list
7343 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7344 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7345 This is a direct interface to the
7349 function of the OpenSSL library, if available; see
7351 for more information.
7352 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7354 specific cipher (protocol standards ship with a list of acceptable
7355 ciphers), possibly cramped to what the actually used SSL/TLS library
7356 supports \(en the manual section
7357 .Sx "An example configuration"
7358 also contains a SSL/TLS use case.
7361 .It Va ssl-config-file
7362 \*(OP If this variable is set \*(UA will call
7363 .Xr CONF_modules_load_file 3
7364 to allow OpenSSL to be configured according to the host system wide
7366 If a non-empty value is given then this will be used to specify the
7367 configuration file to be used instead of the global OpenSSL default;
7368 note that in this case it is an error if the file cannot be loaded.
7369 The application name will always be passed as
7374 \*(OP Specifies a file that contains a CRL in PEM format to use when
7375 verifying SSL/TLS server certificates.
7379 \*(OP Specifies a directory that contains files with CRLs in PEM format
7380 to use when verifying SSL/TLS server certificates.
7383 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7384 \*(OP Variable chain that sets the file name for the private key of
7385 a SSL/TLS client certificate.
7386 If unset, the name of the certificate file is used.
7387 The file is expected to be in PEM format.
7388 This is a direct interface to the
7392 function of the OpenSSL library, if available.
7395 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7397 \*(OB Please use the newer and more flexible
7399 instead: if both values are set,
7401 will take precedence!
7402 Can be set to the following values, the actually used
7404 specification to which it is mapped is shown in parenthesis:
7406 .Pf ( Ql -ALL, TLSv1.2 ) ,
7408 .Pf ( Ql -ALL, TLSv1.1 ) ,
7410 .Pf ( Ql -ALL, TLSv1 )
7413 .Pf ( Ql -ALL, SSLv3 ) ;
7418 and thus includes the SSLv3 protocol.
7419 Note that SSLv2 is no longer supported at all.
7422 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7423 \*(OP Specify the used SSL/TLS protocol.
7424 This is a direct interface to the
7428 function of the OpenSSL library, if available;
7429 otherwise an \*(UA internal parser is used which understands the
7430 following subset of (case-insensitive) command strings:
7436 as well as the special value
7438 Multiple specifications may be given via a comma-separated list which
7439 ignores any whitespace.
7442 plus prefix will enable a protocol, a
7444 minus prefix will disable it, so that
7446 will enable only the TLSv1.2 protocol.
7448 It depends upon the used TLS/SSL library which protocols are actually
7449 supported and which protocols are used if
7451 is not set, but note that SSLv2 is no longer supported at all and
7453 Especially for older protocols explicitly securing
7455 may be worthwile, see
7456 .Sx "An example configuration" .
7460 \*(OP Gives the pathname to an entropy daemon socket, see
7462 Not all SSL/TLS libraries support this.
7465 .It Va ssl-rand-file
7466 \*(OP Gives the pathname to a file with entropy data, see
7467 .Xr RAND_load_file 3 .
7468 If the file is a regular file writable by the invoking user,
7469 new data is written to it after it has been loaded.
7472 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7473 \*(OP Variable chain that sets the action to be performed if an error
7474 occurs during SSL/TLS server certificate validation.
7475 Valid (case-insensitive) values are
7477 (fail and close connection immediately),
7479 (ask whether to continue on standard input),
7481 (print a warning and continue),
7483 (do not perform validation).
7489 If only set without an assigned value, then this option inhibits the
7494 header fields that include obvious references to \*(UA.
7495 There are two pitfalls associated with this:
7496 First, the message id of outgoing messages is not known anymore.
7497 Second, an expert may still use the remaining information in the header
7498 to track down the originating mail user agent.
7503 suppression doesn't occur.
7507 If defined, gives the number of lines of a message to be printed out
7508 with the top command; normally, the first five lines are printed.
7512 The character set of the terminal \*(UA operates on,
7513 and the one and only supported character set that \*(UA can use if no
7514 character set conversion capabilities have been compiled into it,
7515 in which case it defaults to ISO-8859-1 unless it can deduce a value
7519 Refer to the section
7520 .Sx "Character sets"
7521 for the complete picture about character sets.
7524 .It Va user-HOST , user
7525 \*(IN Variable chain that sets a global fallback user name, which is
7526 used in case none has been given in the protocol and account-specific
7528 This variable defaults to the value of
7535 .It Va version , version-major , version-minor , version-update
7536 \*(RO \*(UA version information: the first variable contains a string
7537 containing the complete version identification \(en this is identical to
7538 the output of the command
7540 The latter three contain only digits: the major, minor and update
7544 .\" }}} (Variable options)
7547 .\" .Sh ENVIRONMENT {{{
7551 .Dq environment variable
7552 should be considered an indication that the following variables are
7553 either standardized as being vivid parts of process environments, or
7554 are commonly found in there.
7555 Unless otherwise explicitly noted they integrate into the normal
7556 variable handling, as documented above, from \*(UAs point of view.
7558 .Bl -tag -width ".It Ev _AILR_"
7561 The user's preferred width in column positions for the terminal screen
7563 Queried and used once on program startup.
7567 The name of the file to use for saving aborted messages if
7569 is set; this defaults to
7577 Pathname of the text editor to use in the
7581 .Sx "TILDE ESCAPES" .
7582 A default editor is used if this value is not defined.
7586 The user's home directory.
7587 This variable is only used when it resides in the process environment.
7590 to update the value at runtime.
7597 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
7601 .Sx "Character sets" .
7605 The user's preferred number of lines on a page or the vertical screen
7606 or window size in lines.
7607 Queried and used once on program startup.
7611 Pathname of the directory lister to use in the
7613 command when operating on local mailboxes.
7616 (path search through
7621 The name of the user's mbox file.
7622 Supports a logical subset of the special conventions that are
7628 The fallback default is
7635 Is used as the user's primary system mailbox, unless
7639 This is assumed to be an absolute pathname.
7643 Is used as a startup file instead of
7646 When \*(UA scripts are invoked on behalf of other users,
7647 this variable should be set to
7649 to avoid side-effects from reading their configuration files.
7650 This variable is only used when it resides in the process environment.
7653 .It Ev NAIL_NO_SYSTEM_RC
7654 If this variable is set then reading of
7656 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
7657 had been started up with the option
7659 This variable is only used when it resides in the process environment.
7663 \*(IN \*(OP This variable overrides the default location of the user's
7669 Pathname of the program to use in the more command or when the
7672 The default paginator is
7674 (path search through
7679 A list of directories that is searched by the shell when looking for
7680 commands (as such only recognized in the process environment).
7684 The shell to use for the commands
7690 and when starting subprocesses.
7691 A default shell is used if this option is not defined.
7695 Changes the letters printed in the first column of a header summary.
7699 \*(OP The terminal type for which output is to be prepared.
7703 Used as directory for temporary files instead of
7706 This variable is only used when it resides in the process environment.
7709 to update the value at runtime.
7713 Force identification as the given user, i.e., identical to the
7715 command line option.
7716 This variable is only used when it resides in the process environment.
7719 to update the value at runtime, but note that doing so won't trigger any
7720 of those validation checks that were performed on program startup (again).
7724 Pathname of the text editor to use in the
7728 .Sx "TILDE ESCAPES" .
7736 .Bl -tag -width ".It Pa _etc/mime.type_"
7738 File giving initial commands.
7741 System wide initialization file.
7744 .It Pa ~/.mime.types
7745 Personal MIME types, see
7746 .Sx "The mime.types files" .
7749 .It Pa /etc/mime.types
7750 System wide MIME types, see
7751 .Sx "The mime.types files" .
7755 \*(IN \*(OP The default location of the users
7757 file \(en the section
7758 .Sx "The .netrc file"
7759 documents the file format.
7762 .\" .Ss "The mime.types files" {{{
7763 .Ss "The mime.types files"
7765 When sending messages \*(UA tries to determine the content type of all
7767 When displaying message content or attachments \*(UA uses the content
7768 type to decide whether it can directly display data or whether it needs to
7769 deal with content handlers, as can be defined via
7770 .Va pipe-TYPE/SUBTYPE
7772 .Va pipe-EXTENSION )
7773 variables, to do so.
7776 It learns about MIME types and how to treat them by reading
7778 files, the loading of which can be controlled by setting the variable
7779 .Va mimetypes-load-control .
7782 can also be used to deal with MIME types.)
7784 files have the following syntax:
7787 .Dl type/subtype extension [extension ...]
7792 are strings describing the file contents, and one or multiple
7794 s, separated by whitespace, name the part of a filename starting after
7795 the last dot (of interest).
7796 Comments may be introduced anywhere on a line with a number sign
7798 causing the remaining line to be discarded.
7800 \*(UA also supports an extended, non-portable syntax in specially
7801 crafted files, which can be loaded via the alternative value syntax of
7802 .Va mimetypes-load-control
7803 and prepends an optional
7807 .Dl [type-marker ]type/subtype extension [extension ...]
7810 The following type markers are supported:
7813 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
7815 Treat message parts with this content as plain text.
7820 Treat message parts with this content as HTML tagsoup.
7821 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
7822 the content as plain text instead.
7826 but instead of falling back to plain text require an explicit content
7827 handler to be defined.
7832 for sending messages:
7833 .Va mime-allow-text-controls .
7834 For reading etc. messages:
7835 .Sx "Viewing HTML mail and MIME attachments" ,
7836 .Va mime-counter-evidence ,
7837 .Va pipe-TYPE/SUBTYPE ,
7838 .Va pipe-EXTENSION .
7841 .\" .Ss "The .netrc file" {{{
7842 .Ss "The .netrc file"
7846 file contains user credentials for machine accounts.
7847 The default location in the user's
7849 directory may be overridden by the
7851 environment variable.
7852 The file consists of space, tabulator or newline separated tokens.
7853 \*(UA implements a parser that supports a superset of the original BSD
7854 syntax, but users should nonetheless be aware of portability glitches
7855 of that file format, shall their
7857 be usable across multiple programs and platforms:
7860 .Bl -bullet -compact
7862 BSD doesn't support single, but only double quotation marks, e.g.,
7863 .Ql password="pass with spaces" .
7865 BSD (only?) supports escaping of single characters via a backslash
7866 (e.g., a space can be escaped via
7868 in- as well as outside of a quoted string.
7870 BSD doesn't require the final quotation mark of the final user input token.
7872 At least Hewlett-Packard seems to support a format which also allows
7873 tokens to be separated with commas \(en this format is not supported!
7875 Whereas other programs may require that the
7877 file is accessible by only the user if it contains a
7883 \*(UA will always require these strict permissions.
7887 Of the following list of supported tokens \*(UA only uses (and caches)
7893 .Bl -tag -width password
7894 .It Cd machine Ar name
7895 The hostname of the entries' machine, lowercase-normalized by \*(UA
7897 Any further file content, until either end-of-file or the occurrence
7902 first-class token is bound (only related) to the machine
7905 As an extension that shouldn't be the cause of any worries
7906 \*(UA supports a single wildcard prefix for
7908 .Bd -literal -offset indent
7909 machine *.example.com login USER password PASS
7910 machine pop3.example.com login USER password PASS
7911 machine smtp.example.com login USER password PASS
7917 .Ql pop3.example.com ,
7921 .Ql local.smtp.example.com .
7922 Note that in the example neither
7923 .Ql pop3.example.com
7925 .Ql smtp.example.com
7926 will be matched by the wildcard, since the exact matches take
7927 precedence (it is however faster to specify it the other way around).
7932 except that it is a fallback entry that is used shall none of the
7933 specified machines match; only one default token may be specified,
7934 and it must be the last first-class token.
7936 .It Cd login Ar name
7937 The user name on the remote machine.
7939 .It Cd password Ar string
7940 The user's password on the remote machine.
7942 .It Cd account Ar string
7943 Supply an additional account password.
7944 This is merely for FTP purposes.
7946 .It Cd macdef Ar name
7948 A macro is defined with the specified
7950 it is formed from all lines beginning with the next line and continuing
7951 until a blank line is (consecutive newline characters are) encountered.
7954 entries cannot be utilized by multiple machines, too, but must be
7955 defined following the
7957 they are intended to be used with.)
7960 exists, it is automatically run as the last step of the login process.
7961 This is merely for FTP purposes.
7968 .\" .Sh EXAMPLES {{{
7971 .\" .Ss "An example configuration" {{{
7972 .Ss "An example configuration"
7974 .Bd -literal -offset indent
7975 # This example assumes v15.0 compatibility mode
7978 # Where are the up-to-date SSL certificates?
7979 #set ssl-ca-dir=/etc/ssl/certs
7980 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
7982 # (Since we manage up-to-date ones explicitly, don't use any,
7983 # possibly outdated, default certificates shipped with OpenSSL
7984 set ssl-no-default-ca
7986 # Don't use protocols olders than TLS v1.2.
7987 # Change this only when the remote server doesn't support it:
7988 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
7989 # such explicit exceptions, then
7990 set ssl-protocol="-ALL,+TLSv1.2"
7992 # Explicitly define the list of ciphers, which may improve security,
7993 # especially with protocols older than TLS v1.2. See ciphers(1).
7994 # Hint: it is important to include "@STRENGTH": only with it the
7995 # final list will be sorted by algorithm strength.
7996 # This is an example: in reality it is possibly best to only use
7997 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
7998 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
7999 !MD5:!RC4:!EXPORT:@STRENGTH"
8001 # Request strict transport security checks!
8002 set ssl-verify=strict
8004 # Essential setting: select allowed character sets
8005 set sendcharsets=utf-8,iso-8859-1
8007 # A very kind option: when replying to a message, first try to
8008 # use the same encoding that the original poster used herself!
8009 set reply-in-same-charset
8011 # When replying to or forwarding a message the comment and name
8012 # parts of email addresses are removed unless this variable is set
8015 # When sending messages, wait until the Mail-Transfer-Agent finishs.
8016 # Only like this you'll be able to see errors reported through the
8017 # exit status of the MTA (including the builtin SMTP one)!
8020 # Only use builtin MIME types, no mime.types(5) files
8021 set mimetypes-load-control
8023 # Default directory where we act in (relative to $HOME)
8024 set folder=mail MBOX=+mbox.mbox record=+sent.mbox \e
8027 # Make "file mymbox" and "file myrec" go to..
8028 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
8030 # Not really optional, e.g., for S/MIME
8031 set from="Your Name <youremail@domain>"
8033 # It may be necessary to set hostname and/or smtp-hostname
8034 # if the "SERVER" of smtp and "domain" of from don't match.
8035 # The `urlencode' command can be used to encode USER and PASS
8036 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
8037 smtp-auth=login/plain... \e
8040 # Never refuse to start into interactive mode, and more
8042 colour-pager crt= followup-to followup-to-honour=ask-yes \e
8043 history-gabby mime-counter-evidence=6 \e
8044 prompt="\e033[31m?\e?[\e$ \e@]\e& \e033[0m" \e
8045 NAIL_HISTFILE=+.s-nailhist NAIL_HISTSIZE=-1 \e
8046 reply-to-honour=ask-yes
8048 # When `p'rinting messages, show only these headers
8049 # (use `P'rint for all headers and `S'how for raw message)
8050 retain date from to cc subject
8052 # Some mailing lists
8053 mlist @xyz-editor.xyz$ @xyzf.xyz$
8054 mlsubscribe ^xfans@xfans.xyz$
8056 # A real life example of a very huge free mail provider
8059 set from="Your Name <youremail@domain>"
8060 # (The plain smtp:// proto is optional)
8061 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
8064 # Here is a pretty large one which does not allow sending mails
8065 # if there is a domain name mismatch on the SMTP protocol level,
8066 # which would bite us if the value of from does not match, e.g.,
8067 # for people who have a sXXXXeforge project and want to speak
8068 # with the mailing list under their project account (in from),
8069 # still sending the message through their normal mail provider
8072 set from="Your Name <youremail@domain>"
8073 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
8074 hostname=yaXXex.com smtp-hostname=
8077 # Create some new commands so that, e.g., `ls /tmp' will..
8088 ghost llS !ls -aFlrS
8091 # We don't support gpg(1) directly yet. But simple --clearsign'd
8092 # message parts can be dealt with as follows:
8095 set pipe-text/plain="set -C;\e
8096 : > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" \e
8097 trap \e"rm -f \e\e\e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e\e\e"\e" \e
8098 EXIT INT QUIT PIPE TERM;\e
8100 cat > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e";\e
8101 < \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" awk \e
8102 -v TMPFILE=\e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" '\e
8104 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
8107 print \e"--- GPG --verify ---\e";\e
8108 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
8109 print \e"--- GPG --verify ---\e";\e
8113 /^-----BEGIN PGP SIGNATURE-----/,\e
8114 /^-----END PGP SIGNATURE-----/ {\e
8124 !printf 'Key IDs to gpg --recv-keys: ';\e
8126 gpg --recv-keys ${keyids};
8132 When storing passwords in
8134 appropriate permissions should be set on this file with
8135 .Ql $ chmod 0600 \*(ur .
8138 is available user credentials can be stored in the central
8140 file instead; e.g., here is a different version of the example account
8141 that sets up SMTP and POP3:
8143 .Bd -literal -offset indent
8146 set from="Your Name <youremail@domain>"
8148 #set agent-shell-lookup="gpg -d .pass.gpg"
8150 set smtp=smtps://smtp.yXXXXx.ru:465 \e
8151 smtp-hostname= hostname=yXXXXx.com
8152 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
8153 ghost xp fi pop3s://pop.yXXXXx.ru
8162 .Bd -literal -offset indent
8163 machine *.yXXXXx.ru login USER password PASS
8168 .Va agent-shell-lookup
8169 is available things could be diversified further by using encrypted
8170 password storage: for this, don't specify
8174 file and instead uncomment the line that defines agent lookup in the
8177 above, then create the encrypted password storage file
8180 .Bd -literal -offset indent
8183 $ eval `gpg-agent --daemon \e
8184 --pinentry-program=/usr/bin/pinentry-curses \e
8185 --max-cache-ttl 99999 --default-cache-ttl 99999`
8189 This configuration should now work just fine (use the
8191 command line option for a(n almost) dry-run):
8194 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
8197 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
8198 .Ss "Signed and encrypted messages with S/MIME"
8200 \*(OP S/MIME provides two central mechanisms:
8201 message signing and message encryption.
8202 A signed message contains some data in addition to the regular text.
8203 The data can be used to verify that the message was sent using a valid
8204 certificate, that the sender's address in the message header matches
8205 that in the certificate, and that the message text has not been altered.
8206 Signing a message does not change its regular text;
8207 it can be read regardless of whether the recipient's software is able to
8211 It is thus usually possible to sign all outgoing messages if so desired.
8212 Encryption, in contrast, makes the message text invisible for all people
8213 except those who have access to the secret decryption key.
8214 To encrypt a message, the specific recipient's public encryption key
8216 It is therefore not possible to send encrypted mail to people unless their
8217 key has been retrieved from either previous communication or public key
8219 A message should always be signed before it is encrypted.
8220 Otherwise, it is still possible that the encrypted message text is
8224 A central concept to S/MIME is that of the certification authority (CA).
8225 A CA is a trusted institution that issues certificates.
8226 For each of these certificates it can be verified that it really
8227 originates from the CA, provided that the CA's own certificate is
8229 A set of CA certificates is usually delivered with OpenSSL and installed
8231 If you trust the source of your OpenSSL software installation,
8232 this offers reasonable security for S/MIME on the Internet.
8234 .Va ssl-no-default-ca
8238 .Va smime-ca-dir . )
8239 In general, a certificate cannot be more secure than the method its CA
8240 certificate has been retrieved with, though.
8241 Thus if you download a CA certificate from the Internet,
8242 you can only trust the messages you verify using that certificate as
8243 much as you trust the download process.
8246 The first thing you need for participating in S/MIME message exchange is
8247 your personal certificate, including a private key.
8248 The certificate contains public information, in particular your name and
8249 your email address(es), and the public key that is used by others to
8250 encrypt messages for you,
8251 and to verify signed messages they supposedly received from you.
8252 The certificate is included in each signed message you send.
8253 The private key must be kept secret.
8254 It is used to decrypt messages that were previously encrypted with your
8255 public key, and to sign messages.
8258 For personal use it is recommended that you get a S/MIME certificate
8259 from one of the major CAs on the Internet using your WWW browser.
8260 Many CAs offer such certificates for free.
8262 .Lk https://www.CAcert.org
8263 which issues client and server certificates to members of their
8264 community for free; their root certificate
8265 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
8266 is often not in the default set of trusted CA root certificates, though,
8267 which means you will have to download their root certificate separately
8268 and ensure it is part of our S/MIME certificate validation chain by
8271 or as a vivid member of the
8273 But let's take a step-by-step tour on how to setup S/MIME with
8274 a certificate from CAcert.org despite this situation!
8277 First of all you will have to become a member of the CAcert.org
8278 community, simply by registrating yourself via the web interface.
8279 Once you are, create and verify all email addresses you want to be able
8280 to create signed and encrypted messages for/with using the corresponding
8281 entries of the web interface.
8282 Now ready to create S/MIME certificates, so let's create a new
8283 .Dq client certificate ,
8284 ensure to include all email addresses that should be covered by the
8285 certificate in the following web form, and also to use your name as the
8289 Create a private key and a certificate request on your local computer
8290 (please see the manual pages of the used commands for more in-depth
8291 knowledge on what the used arguments etc. do):
8294 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
8297 Afterwards copy-and-paste the content of
8299 into the certificate-request (CSR) field of the web form on the
8300 CAcert.org website (you may need to unfold some
8301 .Dq advanced options
8302 to see the corresponding text field).
8303 This last step will ensure that your private key (which never left your
8304 box) and the certificate belong together (through the public key that
8305 will find its way into the certificate via the certificate-request).
8306 You are now ready and can create your CAcert certified certificate.
8307 Download and store or copy-and-paste it as
8312 In order to use your new S/MIME setup you will have to create
8313 a combined private key/public key (certificate) file:
8316 .Dl cat key.pem pub.crt > ME@HERE.com.paired
8319 This is the file \*(UA will work with.
8320 If you have created your private key with a passphrase then \*(UA will
8321 ask you for it whenever a message is signed or decrypted.
8322 Set the following variables to henceforth use S/MIME (setting
8324 is of interest for verification only):
8326 .Bd -literal -offset indent
8327 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
8328 smime-sign-cert=ME@HERE.com.paired \e
8329 smime-sign-message-digest=SHA256 \e
8334 From each signed message you send, the recipient can fetch your
8335 certificate and use it to send encrypted mail back to you.
8336 Accordingly if somebody sends you a signed message, you can do the same,
8339 command to check the validity of the certificate.
8342 Options of interest for S/MIME signing:
8346 .Va smime-crl-file ,
8347 .Va smime-no-default-ca ,
8349 .Va smime-sign-cert ,
8350 .Va smime-sign-include-certs
8352 .Va smime-sign-message-digest .
8355 After it has been verified save the certificate via
8357 and tell \*(UA that it should use it for encryption for further
8358 communication with that somebody:
8360 .Bd -literal -offset indent
8362 set smime-encrypt-USER@HOST=FILENAME \e
8363 smime-cipher-USER@HOST=AES256
8367 Additional options of interest for S/MIME en- and decryption:
8370 .Va smime-encrypt-USER@HOST .
8373 You should carefully consider if you prefer to store encrypted messages
8375 If you do, anybody who has access to your mail folders can read them,
8376 but if you do not, you might be unable to read them yourself later if
8377 you happen to lose your private key.
8380 command saves messages in decrypted form, while the
8384 commands leave them encrypted.
8387 Note that neither S/MIME signing nor encryption applies to message
8388 subjects or other header fields yet.
8389 Thus they may not contain sensitive information for encrypted messages,
8390 and cannot be trusted even if the message content has been verified.
8391 When sending signed messages,
8392 it is recommended to repeat any important header information in the
8396 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
8397 .Ss "Using CRLs with S/MIME or SSL/TLS"
8399 \*(OP Certification authorities (CAs) issue certificate revocation
8400 lists (CRLs) on a regular basis.
8401 These lists contain the serial numbers of certificates that have been
8402 declared invalid after they have been issued.
8403 Such usually happens because the private key for the certificate has
8405 because the owner of the certificate has left the organization that is
8406 mentioned in the certificate, etc.
8407 To seriously use S/MIME or SSL/TLS verification,
8408 an up-to-date CRL is required for each trusted CA.
8409 There is otherwise no method to distinguish between valid and
8410 invalidated certificates.
8411 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
8412 the Internet, so you have to retrieve them by some external mechanism.
8415 \*(UA accepts CRLs in PEM format only;
8416 CRLs in DER format must be converted, like, e.\|g.:
8419 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
8422 To tell \*(UA about the CRLs, a directory that contains all CRL files
8423 (and no other files) must be created.
8428 variables, respectively, must then be set to point to that directory.
8429 After that, \*(UA requires a CRL to be present for each CA that is used
8430 to verify a certificate.
8433 .\" .Ss "Handling spam" {{{
8436 \*(OP \*(UA can make use of several spam interfaces for the purpose of
8437 identification of, and, in general, dealing with spam messages.
8438 A precondition of most commands in order to function is that the
8440 variable is set to one of the supported interfaces.
8441 Once messages have been identified as spam their (volatile)
8443 state can be prompted: the
8447 message specifications will address respective messages and their
8449 entries will be used when displaying the
8451 in the header display.
8456 rates the given messages and sets their
8459 If the spam interface offers spam scores those can also be displayed in
8460 the header display by including the
8470 will interact with the Bayesian filter of the chosen interface and learn
8471 the given messages as
8475 respectively; the last command can be used to cause
8477 of messages; it adheres to their current
8479 state and thus reverts previous teachings.
8484 will simply set and clear, respectively, the mentioned volatile
8486 message flag, without any interface interaction.
8493 .Va spam-interface Ns s
8497 require a running instance of the
8499 server in order to function, started with the option
8501 shall Bayesian filter learning be possible.
8503 only works via a local path-based
8505 socket, but otherwise the following will be equivalently fine:
8507 .Bd -literal -offset indent
8508 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
8509 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
8510 --daemonize [--local] [--allow-tell]
8514 Thereafter \*(UA can make use of these interfaces:
8516 .Bd -literal -offset indent
8517 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
8518 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
8520 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
8521 -Sspamc-command=/usr/local/bin/spamc \e
8522 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
8524 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
8525 -Sspamc-command=/usr/local/bin/spamc \e
8526 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
8530 Using the generic filter approach allows usage of programs like
8534 Here is an example for the former, requiring it to be accessible via
8537 .Bd -literal -offset indent
8538 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
8539 -Sspamfilter-ham="bogofilter -n" \e
8540 -Sspamfilter-noham="bogofilter -N" \e
8541 -Sspamfilter-nospam="bogofilter -S" \e
8542 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
8543 -Sspamfilter-spam="bogofilter -s" \e
8544 -Sspamfilter-rate-scanscore="1;^(.+)$"
8548 Because messages must exist on local storage in order to be scored (or
8549 used for Bayesian filter training), it is possibly a good idea to
8550 perform the local spam check last:
8552 .Bd -literal -offset indent
8553 define spamdelhook {
8555 spamset (header x-dcc-brand-metrics "bulk")
8556 # Server-side spamassassin(1)
8557 spamset (header x-spam-flag "YES")
8558 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
8564 set folder-hook-FOLDER=spamdelhook
8568 See also the documentation for the variables
8569 .Va spam-interface , spam-maxsize ,
8570 .Va spamc-command , spamc-arguments , spamc-user ,
8571 .Va spamd-socket , spamd-user ,
8572 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
8575 .Va spamfilter-rate-scanscore .
8583 .\" .Ss "\*(UA shortly hangs on startup" {{{
8584 .Ss "\*(UA shortly hangs on startup"
8586 This can have two reasons, one is the necessity to wait for a file lock
8587 and can't be helped, the other being that \*(UA calls the function
8589 in order to query the nodename of the box (sometimes the real one is
8590 needed instead of the one represented by the internal variable
8592 You may have varying success by ensuring that the real hostname and
8596 or, more generally, that the name service is properly setup \(en
8599 return what you'd expect?
8602 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
8603 .Ss "I can't login to Google mail a.k.a. GMail"
8605 Since 2014 some free service providers classify programs as
8607 unless they use a special authentification method (OAuth 2.0) which
8608 wasn't standardized for non-HTTP protocol authentication token query
8609 until August 2015 (RFC 7628).
8612 Different to Kerberos / GSSAPI, which is developed since the mid of the
8613 1980s, where a user can easily create a local authentication ticket for
8614 her- and himself with the locally installed
8616 program, that protocol has no such local part but instead requires
8617 a world-wide-web query to create or fetch a token; since there is no
8618 local cache this query has to be performed whenever \*(UA is invoked
8619 from the command line (in interactive sessions situation may differ).
8622 \*(UA doesn't support OAuth.
8623 Because of this it is necessary to declare \*(UA a
8625 (on the providers account web page) in order to read and send mail.
8626 However, it also seems possible to take the following steps instead:
8631 give the provider the number of a mobile phone,
8634 .Dq 2-Step Verification ,
8636 create an application specific password (16 characters), and
8638 use that special password instead of your real Google account password in
8639 S-nail (for more on that see the section
8640 .Sx "On URL syntax and credential lookup" ) .
8646 .\" .Sh "SEE ALSO" {{{
8664 .Xr spamassassin 1 ,
8691 command appeared in Version 1 AT&T Unix.
8692 Berkeley Mail was written in 1978 by Kurt Shoens.
8693 This man page is derived from from
8694 .Dq The Mail Reference Manual
8695 originally written by Kurt Shoens.
8697 enhancements are maintained and documented by Gunnar
8700 is maintained and documented by Steffen (Daode) Nurpmeso.
8703 Portions of this text are reprinted and reproduced in electronic form
8704 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
8705 \(en Operating System Interface (POSIX), The Open Group Base
8706 Specifications Issue 6, Copyright \(co 2001-2003 by the Institute of
8707 Electrical and Electronics Engineers, Inc and The Open Group.
8708 In the event of any discrepancy between this version and the original
8709 IEEE and The Open Group Standard, the original IEEE and The Open Group
8710 Standard is the referee document.
8711 The original Standard can be obtained online at
8712 .Lk http://www.opengroup.org/unix/online.html OpenGroup.org
8713 Redistribution of this material is permitted so long as this notice
8721 .An "Christos Zoulas" ,
8722 .An "Gunnar Ritter" ,
8723 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
8725 .Mt s-mailx@sdaoden.eu ) .
8731 The character set conversion uses and relies upon the
8734 Its functionality differs widely between the various system environments
8738 Limitations with IMAP mailboxes are:
8739 It is not possible to edit messages, but it is possible to append them.
8740 Thus to edit a message, create a local copy of it, edit it, append it,
8741 and delete the original.
8742 The line count for the header display is only appropriate if the entire
8743 message has been downloaded from the server.
8744 The marking of messages as `new' is performed by the IMAP server;
8749 will not cause it to be reset, and if the
8751 variable is unset, messages that arrived during a session will not be
8752 in state `new' anymore when the folder is opened again.
8753 Also if commands queued in disconnected mode are committed,
8754 the IMAP server will delete the `new' flag for all messages in the
8756 and new messages will appear as unread when it is selected for viewing
8758 The `flagged', `answered', and `draft' attributes are usually permanent,
8759 but some IMAP servers are known to drop them without notification.
8760 Message numbers may change with IMAP every time before the prompt is
8761 printed if \*(UA is notified by the server that messages have been
8762 deleted by some other client or process.
8763 In this case, `Expunged n messages' is printed, and message numbers may
8767 Limitations with POP3 mailboxes are:
8768 It is not possible to edit messages, they can only be copied and deleted.
8769 The line count for the header display is only appropriate if the entire
8770 message has been downloaded from the server.
8771 The status field of a message is maintained by the server between
8772 connections; some servers do not update it at all, and with a server
8775 command will not cause the message status to be reset.
8780 variable have no effect.
8781 It is not possible to rename or to remove POP3 mailboxes.
8788 is typed while an IMAP or POP3 operation is in progress, \*(UA will wait
8789 until the operation can be safely aborted, and will then return to the
8790 command loop and print the prompt again.
8793 is typed while \*(UA is waiting for the operation to complete, the
8794 operation itself will be cancelled.
8795 In this case, data that has not been fetched yet will have to be fetched
8796 before the next command can be performed.
8797 If the cancelled operation was using an SSL/TLS encrypted channel,
8798 an error in the SSL transport will very likely result and render the
8799 connection unusable.
8802 As \*(UA is a mail user agent, it provides only basic SMTP services.
8803 If it fails to contact its upstream SMTP server, it will not make
8804 further attempts to transfer the message at a later time,
8805 and it does not leave other information about this condition than an
8806 error message on the terminal and an entry in
8808 This is usually not a problem if the SMTP server is located in the same
8809 local network as the computer on which \*(UA is run.
8810 However, care should be taken when using a remote server of an ISP;
8811 it might be better to set up a local SMTP server then which just acts as
8815 \*(UA immediately contacts the SMTP server (or
8817 ) even when operating in
8820 It would not make much sense for \*(UA to defer outgoing mail since SMTP
8821 servers usually provide much more elaborated delay handling than \*(UA
8822 could perform as a client.
8823 Thus the recommended setup for sending mail in
8825 mode is to configure a local SMTP server such that it sends outgoing
8826 mail as soon as an external network connection is available again,
8827 i.e., to advise it to do that from a network startup script.
8833 With IMAP, at least if the IMAP cache is used, if multiple
8837 cycles happen without an intervening change of the active mailbox then
8838 \*(UA will at some time loose the ability to keep the local state
8839 up-to-date, meaning that, e.g., messages show up with false numbers, and
8840 including the possibility that messages are accessed via numbers that
8841 are no(t longer) valid, resulting in program crashes.
8842 The solution is to change the active mailbox before that happens :).
8845 from the distribution or the repository.
8847 After deleting some message of a POP3 mailbox the header summary falsely
8848 claims that there are no messages to display, you need to perform
8849 a scroll or dot movement to restore proper state.
8851 In threaded display a power user may encounter crashes very
8852 occasionally (this is may and very).