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
28 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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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): v14.8.14 / 2016-10-20
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 variable names are expected not to be
1774 URL percent encoded.
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 (\*(ID and non-empty), the standardized absolute pathname
2655 if that is set, or a builtin compile-time default otherwise.
2656 (\*(OB For IMAP folders only, and only if
2658 is not set, the value of
2660 is inspected and used if found.)
2662 means the system mailbox of
2664 (and never the value of
2668 regardless of their actual setting),
2670 (ampersand) means the invoking user's
2680 expands to the same value as
2682 but the file is handled as a system mailbox by, e.g., the
2686 commands, meaning that messages that have been read in the current
2687 session will be moved to the
2689 mailbox instead of simply being flagged as read.
2692 If the name matches one of the strings defined with the command
2694 it is replaced by its long form and expanded.
2695 If the name ends with
2700 it is treated as being compressed with
2705 respectively, and transparently handled through an intermediate
2706 (un)compression step (using a temporary file) with the according
2707 facility, sufficient support provided.
2708 Likewise, if the named file doesn't exist, but a file with one of the
2709 mentioned compression extensions does, then the name is automatically
2710 expanded and the compressed file is used.
2712 Otherwise, if the name ends with an extension for which
2713 .Va file-hook-load-EXTENSION
2715 .Va file-hook-save-EXTENSION
2716 variables are set, then the given hooks will be used to load and save
2718 and \*(UA will work with an intermediate temporary file.
2720 MBOX files (flat file-based mailboxes) are generally locked during file
2721 operations in order to avoid inconsistencies against concurrent
2723 Mailbox files which \*(UA treats as system mailboxes will also be
2724 protected by so-called dotlock files, the traditional way of mail spool
2725 file locking: for any file
2729 will be created for the duration of the synchronization \(em
2730 as necessary a privilege-separated dotlock child process will be used
2731 to accommodate for necessary privilege adjustments in order to create
2732 the dotlock file in the same directory
2733 and with the same user and group identities as the file of interest.
2737 refers to a directory with the subdirectories
2742 then it is treated as a folder in
2747 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
2748 .Dl \*(OU protocol://[user@]host[:port][/path]
2750 is taken as an Internet mailbox specification.
2751 The \*(OPally supported protocols are
2755 (POP3 with SSL/TLS encrypted transport).
2758 part is valid only for IMAP.
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.
2772 The optional `path' part applies to IMAP only;
2773 if it is omitted, the default `INBOX' is used.
2774 (IMAP paths undergo inspections and possible transformations before use
2777 can be used to manually apply them to any given argument).
2778 Hierarchy delimiters are normalized, a step which is configurable via the
2780 variable chain, but defaults to the first seen delimiter otherwise.
2781 \*(UA supports internationalised IMAP names, and en- and decodes the
2782 names from and to the
2784 as necessary and possible.
2785 If \*(UA is connected to an IMAP server,
2786 a name of the form `@mailbox' refers to the `mailbox' on that server,
2787 but otherwise a `@' prefix has no special meaning.
2791 Takes a message list and marks the messages as
2793 ged for urgent/special attention.
2794 This mark has no technical meaning in the mail system;
2795 it just causes messages to be highlighted in the header summary,
2796 and makes them specially addressable.
2805 With no arguments, list the names of the folders in the folder directory.
2806 With an existing folder as an argument,
2807 lists the names of folders below the named folder;
2808 e.\|g. the command `folders @' lists the folders on the base level of
2809 the current IMAP server.
2810 See also the variable
2811 .Va imap-list-depth .
2817 but saves the message in a file named after the local part of the first
2818 recipient's address (instead of in
2825 but saves the message in a file named after the local part of the first
2826 recipient's address (instead of in
2833 but responds to all recipients regardless of the
2838 .It Ic followupsender
2841 but responds to the sender only regardless of the
2857 (f) Takes a list of messages and prints their message headers
2858 (which qualifies this command as \*(UAs search facility).
2864 but saves the message in a file named after the local part of the
2865 recipient's address (instead of in
2870 Takes a message and the address of a recipient
2871 and forwards the message to him.
2872 The text of the original message is included in the new one,
2873 with the value of the
2875 variable printed before.
2880 commands specify which header fields are included in the new message.
2881 Only the first part of a multipart message is included unless the
2882 .Va forward-as-attachment
2886 is set recipient addresses will be stripped from comments, names etc.
2890 Specifies which header fields are to be ignored with the command
2892 This command has no effect when the
2893 .Va forward-as-attachment
2898 Specifies which header fields are to be retained with the command
2903 This command has no effect when the
2904 .Va forward-as-attachment
2909 Define or list command aliases, so-called ghosts.
2910 Without arguments a list of all currently known aliases is printed.
2911 With one argument the expansion of the given alias is shown.
2912 With two or more arguments a command alias is defined or updated: the
2913 first argument is the name under which the remaining command line should
2914 be accessible, the content of which can be just about anything.
2915 A ghost can be used everywhere a normal command can be used, but always
2916 takes precedence; any arguments that are given to the command alias are
2917 joined onto the alias content, and the resulting string forms the
2918 command line that is, in effect, executed.
2921 .Bd -literal -offset indent
2923 `ghost': no such alias: "xx"
2926 ghost xx "echo hello,"
2935 (h) Show the current group of headers, the size of which depends on
2938 If a message-specification is given the group of headers containing the
2939 first message therein is shown and the message at the top of the screen
2954 the list of history entries;
2957 argument selects and shows the respective history entry \(en
2960 to accept it, and the history entry will become the new history top.
2961 The default mode if no arguments are given is
2968 Takes a message list and marks each message therein to be saved in the
2969 user's system mailbox instead of in
2971 Does not override the
2974 \*(UA deviates from the POSIX standard with this command, because a
2976 command issued after
2978 will display the following message, not the current one.
2983 (i) Part of the nestable
2984 .Ic if Ns / Ns Ic elif Ns / Ns Ic else Ns / Ns Ic endif
2985 conditional execution construct \(em if the given condition is true then
2986 the encapsulated block is executed.
2987 POSIX only supports the conditions
2992 (execute if standard input is a tty), all remaining conditions are
2993 non-portable extensions; note that falsely specified conditions cause
2994 the execution of the entire conditional construct until the
2997 command to be suppressed.
2998 The syntax of the nestable
3000 conditional execution construct requires that each condition and syntax
3001 element is surrounded by whitespace.
3003 .Bd -literal -offset indent
3012 Another condition can be any boolean value (see the section
3014 for booleans) to mark an enwrapped block as
3017 .Dq always execute .
3018 It is possible to check a variable for existence or compare its
3019 expansion against a user given value or another variable via the
3021 .Pf ( Dq variable next )
3022 conditional trigger character.
3023 The available comparison operators are
3027 (less than or equal to),
3033 (greater than or equal to),
3037 (is substring of) and
3039 (is not substring of).
3040 The values of the left and right hand side are treated as strings and
3041 are compared 8-bit byte-wise, ignoring case according to the rules of
3042 the US-ASCII encoding (therefore, dependend on the active locale,
3043 possibly producing false results for strings in the locale encoding).
3044 Except for the substring checks the comparison will instead be performed
3045 arithmetically if both, the user given value as well as the variable
3046 content, can be parsed as numbers (integers).
3047 An unset variable is treated as the empty string.
3050 When the \*(OPal regular expression support is available, the additional
3056 They treat the right hand side as a regular expression that is matched
3057 case-insensitively and according to the active
3059 locale, meaning that strings in the locale encoding should be matched
3063 Conditions can be joined via AND-OR lists (where the AND operator is
3065 and the OR operator is
3067 which have equal precedence and will be evaluated with left
3068 associativity, thus using the same syntax that is known for the
3070 It is also possible to form groups of conditions and lists by enclosing
3071 them in pairs of brackets
3072 .Ql [\ \&.\&.\&.\ ] ,
3073 which may be interlocked within each other, and also be joined via
3077 The results of individual conditions and entire groups may be modified
3078 via unary operators: the unary operator
3080 will reverse the result.
3082 .Bd -literal -offset indent
3086 if $ttycharset == "UTF-8"
3087 echo *ttycharset* is set to UTF-8, case-insensitively
3091 echo These two variables are equal
3093 if $version-major >= 15
3094 echo Running a new version..
3095 if $features =@ "regex"
3096 if $TERM =~ "^xterm\&.*"
3097 echo ..in an X terminal
3100 if [ [ true ] && [ [ $debug ] || [ $verbose ] ] ]
3103 if true && $debug || $verbose
3104 echo Left associativity, as is known from the shell
3106 if ! ! true && ! [ ! $debug && ! $verbose ]
3107 echo Unary operator support
3115 Without arguments the list of ignored header fields is printed,
3116 otherwise the given list of header fields is added to the ignore list:
3117 Header fields in the ignore list are not printed on the terminal when
3118 a message is printed.
3119 To print a message in its entirety, use the commands
3130 \*(OP Sends command strings directly to the current IMAP server.
3131 \*(UA operates always in IMAP `selected state' on the current mailbox;
3132 commands that change this will produce undesirable results and should be
3134 Useful IMAP commands are:
3135 .Bl -tag -offset indent -width ".Ic getquotearoot"
3137 Takes the name of an IMAP mailbox as an argument and creates it.
3139 (RFC 2087) Takes the name of an IMAP mailbox as an argument
3140 and prints the quotas that apply to the mailbox.
3141 Not all IMAP servers support this command.
3143 (RFC 2342) Takes no arguments and prints the Personal Namespaces,
3144 the Other User's Namespaces and the Shared Namespaces.
3145 Each namespace type is printed in parentheses;
3146 if there are multiple namespaces of the same type,
3147 inner parentheses separate them.
3148 For each namespace a prefix and a hierarchy separator is listed.
3149 Not all IMAP servers support this command.
3154 \*(OP Perform IMAP path transformations on all the given strings.
3155 The first argument specifies the operation:
3157 normalizes hierarchy delimiters (see
3159 and converts the strings from the locale
3161 to the internationalised variant used by IMAP,
3163 does the reverse operation.
3164 Errors are indicated by prepending the output with the string
3174 Prints the names of all available commands, alphabetically sorted.
3178 This command can be used to localize changes to variables, meaning that
3179 their state will be reverted to the former one once the covered scope
3181 It can only be used inside of macro definition blocks introduced by
3185 and is interpreted as a boolean (see
3186 .Sx "Value options" ) ;
3189 of an account is left once it is switched off again.
3190 .Bd -literal -offset indent
3191 define temporary_settings {
3206 enables change localization and calls
3208 which explicitly resets localization, then any value changes within
3210 will still be reverted by
3215 Reply to messages that come in via known
3218 .Pf ( Ic mlsubscribe )
3219 mailing lists, or pretend to do so (see
3220 .Sx "Mailing lists" ) :
3223 functionality this will actively resort and even remove message
3224 recipients in order to generate a message that is supposed to be send to
3226 For example it will also implicitly generate a
3227 .Ql Mail-Followup-To:
3228 header if that seems useful, regardless of the setting of the variable
3235 but saves the message in a file named after the local part of the first
3236 recipient's address (instead of in
3241 (m) Takes a (list of) recipient address(es) as (an) argument(s),
3242 or asks on standard input if none were given;
3243 then collects the remaining mail content and sends it out.
3247 (mb) The given message list is to be sent to
3249 when \*(UA is quit; this is the default action unless the
3252 \*(ID This command can only be used in a system mailbox (see
3257 Without any arguments the content of the MIME type cache will displayed.
3258 Otherwise each argument defines a complete MIME type specification of
3259 a type that shall be added (prepended) to the cache.
3260 In any event MIME type sources are loaded first as necessary \(en
3261 .Va mimetypes-load-control
3262 can be used to fine-tune which sources are actually loaded.
3263 Refer to the section on
3264 .Sx "The mime.types files"
3265 for more on MIME type specifications and this topic in general.
3266 MIME type unregistration and cache resets can be triggered with
3271 Without arguments the list of all currently defined mailing lists
3272 (and their attributes, if any) is printed.
3273 Otherwise all given arguments (which need not be quoted except for
3274 whitespace) will be added and henceforth be recognized as mailing lists.
3275 Mailing lists may be removed via the command
3278 If the \*(OPal regular expression support is available then mailing
3279 lists may also be specified as regular expressions (see
3285 Without arguments the list of all currently defined mailing lists which
3286 have a subscription attribute is printed.
3287 Otherwise this attribute will be set for all given mailing lists,
3288 newly creating them as necessary (as via
3290 Subscription attributes may be removed via the command
3299 but moves the messages to a file named after the local part of the
3300 sender address of the first message (instead of in
3307 but marks the messages for deletion if they were transferred
3314 but also prints ignored header fields and all MIME parts.
3322 on the given messages, even in non-interactive mode and as long as the
3323 standard output is a terminal.
3335 cache, loading the file first as necessary in the former case.
3336 Note that \*(UA will try to read the file only once, use
3337 .Ql Ic netrc Ns \:\0\:clear
3338 to unlock the next attempt.
3342 .Sx "On URL syntax and credential lookup" ;
3344 .Sx "The .netrc file"
3345 documents the file format in detail.
3349 Checks for new mail in the current folder without committing any changes
3351 If new mail is present, a message is printed.
3355 the headers of each new message are also printed.
3363 Goes to the next message in sequence and types it.
3364 With an argument list, types the next matching message.
3378 If the current folder is accessed via a network connection, a
3380 command is sent, otherwise no operation is performed.
3386 but also prints ignored header fields and all MIME parts.
3394 on the given messages, even in non-interactive mode and as long as the
3395 standard output is a terminal.
3403 but also pipes ignored header fields and all parts of MIME
3404 .Ql multipart/alternative
3409 (pi) Takes a message list and a shell command
3410 and pipes the messages through the command.
3411 Without an argument the current message is piped through the command
3418 every message is followed by a formfeed character.
3429 but also prints out ignored header fields and all parts of MIME
3430 .Ql multipart/alternative
3440 (p) Takes a message list and types out each message on the user's
3442 For MIME multipart messages, all parts with a content type of
3446 are shown, the other are hidden except for their headers.
3447 Messages are decrypted and converted to the terminal character set
3452 (q) Terminates the session, saving all undeleted, unsaved messages in
3455 preserving all messages marked with
3459 or never referenced in the system mailbox,
3460 and removing all other messages from the system mailbox.
3461 If new mail has arrived during the session,
3463 .Dq You have new mail
3465 If given while editing a mailbox file with the command line flag
3467 then the edit file is rewritten.
3468 A return to the shell is effected,
3469 unless the rewrite of edit file fails,
3470 in which case the user can escape with the exit command.
3484 Removes the named folders.
3485 The user is asked for confirmation in interactive mode.
3489 Takes the name of an existing folder
3490 and the name for the new folder
3491 and renames the first to the second one.
3492 Both folders must be of the same type
3493 and must be located on the current server for IMAP.
3497 (R) Reply to originator.
3498 Does not reply to other recipients of the original message.
3500 will exchange this command with
3504 is set the recipient address will be stripped from comments, names etc.
3508 (r) Take a message and group-responds to it by addressing the sender
3511 .Va followup-to-honour ,
3514 .Va recipients-in-cc
3515 influence response behaviour.
3518 offers special support for replying to mailing lists.
3521 is set recipient addresses will be stripped from comments, names etc.
3534 but initiates a group-reply regardless of the value of
3541 but responds to the sender only regardless of the value of
3548 but does not add any header lines.
3549 This is not a way to hide the sender's identity,
3550 but useful for sending a message again to the same recipients.
3554 Takes a list of messages and a user name
3555 and sends each message to the named user.
3557 and related header fields are prepended to the new copy of the message.
3575 .It Ic respondsender
3581 (ret) Without arguments the list of retained header fields is printed,
3582 otherwise the given list of header fields is added to the retain list:
3583 Header fields in the retain list are shown on the terminal when
3584 a message is printed, all other header fields are suppressed.
3585 To print a message in its entirety, use the commands
3594 takes precedence over the mentioned.
3600 but saves the messages in a file named after the local part of the
3601 sender of the first message instead of (in
3603 and) taking a filename argument.
3607 (s) Takes a message list and a filename and appends each message in turn
3608 to the end of the file.
3609 If no filename is given, the
3612 The filename in quotes, followed by the generated character count
3613 is echoed on the user's terminal.
3614 If editing a system mailbox the messages are marked for deletion.
3615 Compressed files and IMAP mailboxes are handled as described for the
3617 command line option above.
3634 Header fields thus marked are filtered out when saving a message by
3636 or when automatically saving to
3638 This command should only be applied to header fields that do not contain
3639 information needed to decode the message,
3640 as MIME content fields do.
3641 If saving messages on an IMAP account ignoring fields makes it
3642 impossible to copy the data directly on the server,
3643 thus operation usually becomes much slower.
3655 Header fields thus marked are the only ones saved with a message when
3658 or when automatically saving to
3663 The use of this command is strongly discouraged since it may strip
3664 header fields that are needed to decode the message correctly.
3668 Takes a message list and marks all messages as having been read.
3672 (se) Without arguments this command prints all options and, for
3673 non-binary options, values that are currently known to \*(UA.
3674 Setting any of the options
3678 changes the output format to BSD style, otherwise a properly quoted
3679 listing is produced.
3684 has been set twice then the listing is modified to mark out assembled
3687 Otherwise modifies (set and unsets) the given options.
3688 Arguments are of the form
3690 (no space before or after
3694 if there is no value.
3695 Quotation marks may be placed around any part of the assignment
3696 statement to quote blanks or tabs, e.g.,
3698 .Dl set indentprefix="->"
3700 If an argument begins with
3704 the effect is the same as invoking the
3706 command with the remaining part of the variable
3707 .Pf ( Ql unset save ) .
3713 except that the options are also exported into the program environment;
3714 since this task requires native host support the command will always
3715 report error if that is not available (but still act like
3718 This operation is a no-op unless all resource files have been loaded.
3724 (sh) Invokes an interactive version of the shell.
3728 Without arguments the list of all currently defined shortcuts is
3730 Otherwise all given arguments (which need not be quoted except for
3731 whitespace) are treated as pairs of shortcuts and their expansions,
3732 creating new or changing already existing shortcuts, as necessary.
3733 Shortcuts may be removed via the command
3735 The expansion strings should be in the syntax that has been described
3744 but performs neither MIME decoding nor decryption, so that the raw
3745 message text is shown.
3749 (si) Print the size in characters of each message of the given
3754 Create a sorted representation of the current folder,
3757 command and the addressing modes such that they refer to messages in the
3759 Message numbers are the same as in regular mode.
3763 a header summary in the new order is also printed.
3764 Possible sorting criteria are:
3766 .Bl -tag -compact -offset indent -width "subject"
3768 Sort the messages by their
3770 field, that is by the time they were sent.
3772 Sort messages by the value of their
3774 field, that is by the address of the sender.
3777 variable is set, the sender's real name (if any) is used.
3779 Sort the messages by their size.
3781 \*(OP Sort the message by their spam score, as has been classified by
3784 Sort the messages by their message status.
3786 Sort the messages by their subject.
3788 Create a threaded display.
3790 Sort messages by the value of their
3792 field, that is by the address of the recipient.
3795 variable is set, the recipient's real name (if any) is used.
3798 If no argument is given,
3799 the current sorting criterion is printed.
3803 (so) The source command reads commands from a file.
3809 is that this command will not generate an error if the given file
3810 argument cannot be opened successfully.
3811 This can matter in, e.g., resource files, since loading of those is
3812 stopped when an error is encountered.
3816 \*(OP Takes a list of messages and clears their
3822 \*(OP Takes a list of messages and causes the
3824 to forget it has ever used them to train its Bayesian filter.
3825 Unless otherwise noted the
3827 flag of the message is inspected to chose whether a message shall be
3835 \*(OP Takes a list of messages and informs the Bayesian filter of the
3839 This also clears the
3841 flag of the messages in question.
3845 \*(OP Takes a list of messages and rates them using the configured
3846 .Va spam-interface ,
3847 without modifying the messages, but setting their
3849 flag as appropriate; because the spam rating headers are lost the rate
3850 will be forgotten once the mailbox is left.
3851 Refer to the manual section
3853 for the complete picture of spam handling in \*(UA.
3857 \*(OP Takes a list of messages and sets their
3863 \*(OP Takes a list of messages and informs the Bayesian filter of the
3869 flag of the messages in question.
3878 Create a threaded representation of the current folder,
3879 i.\|e. indent messages that are replies to other messages in the header
3880 display and change the
3882 command and the addressing modes such that they refer to messages in the
3884 Message numbers are the same as in unthreaded mode.
3888 a header summary in threaded order is also printed.
3892 (to) Takes a message list and prints the top few lines of each.
3893 The number of lines printed is controlled by the variable
3895 and defaults to five.
3899 (tou) Takes a message list and marks the messages for saving in
3901 \*(UA deviates from the POSIX standard with this command,
3904 command will display the following message instead of the current one.
3908 (T) Identical to the
3919 Delete all given accounts.
3920 An error message is printed if a given account is not defined.
3923 will discard all existing accounts.
3927 (una) Takes a list of names defined by alias commands
3928 and discards the remembered groups of users.
3931 will discard all existing aliases.
3935 Takes a message list and marks each message as not having been answered.
3939 Only applicable to threaded mode.
3940 Takes a message list and makes the message and all replies to it visible
3941 in header summaries again.
3942 When a message becomes the current message,
3943 it is automatically made visible.
3944 Also when a message with collapsed replies is printed,
3945 all of these are automatically uncollapsed.
3949 Undefine all given macros.
3950 An error message is printed if a given macro is not defined.
3953 will discard all existing macros.
3957 (u) Takes a message list and marks each message as not being deleted.
3961 Takes a message list and
3967 Takes a message list and marks each message as not being
3972 Removes the header field names from the list of ignored fields for the
3977 will remove all fields.
3981 Removes the header field names from the list of retained fields for the
3986 will remove all fields.
3990 Remove all the given command
3994 will remove all ghosts.
3998 Removes the header field names from the list of ignored fields.
4001 will remove all fields.
4005 Delete all given MIME types, e.g.,
4006 .Ql unmimetype text/plain
4007 will remove all registered specifications for the MIME type
4011 will discard all existing MIME types, just as will
4013 but which also reenables cache initialization via
4014 .Va mimetypes-load-control .
4018 Forget about all the given mailing lists.
4021 will remove all lists.
4026 .It Ic unmlsubscribe
4027 Remove the subscription attribute from all given mailing lists.
4030 will clear the attribute from all lists which have it set.
4041 Takes a message list and marks each message as not having been read.
4045 Removes the header field names from the list of retained fields.
4048 will remove all fields.
4052 Removes the header field names from the list of ignored fields for
4056 will remove all fields.
4060 Removes the header field names from the list of retained fields for
4064 will remove all fields.
4068 (uns) Takes a list of option names and discards their remembered values;
4076 except that the options are also removed from the program environment;
4077 since this task requires native host support the command will always
4078 report error if that is not available (but still act like
4081 This operation is a no-op unless all resource files have been loaded.
4087 Deletes the shortcut names given as arguments.
4090 will remove all shortcuts.
4094 Disable sorted or threaded mode
4100 return to normal message order and,
4104 print a header summary.
4114 Perform URL percent codec operations, rather according to RFC 3986,
4115 on all given strings.
4116 This is character set agnostic and thus locale dependent, and it may
4117 decode bytes which are invalid in the current locale, unless the input
4118 solely consists of characters in the portable character set, see
4119 .Sx "Character sets" .
4120 The first argument specifies the operation:
4124 perform plain URL percent en- and decoding, respectively.
4128 perform a slightly modified operation which should be better for
4129 pathnames: it doesn't allow a tilde
4131 and will neither accept hyphen
4135 as an initial character.
4139 Edit the values of or create the given variable(s) in the
4141 Binary variables cannot be edited.
4145 Show informations about all the given options.
4146 \*(UA knows about a finite set of known builtin variables that are
4147 subdivided further in binary and value variants;
4148 they may have special properties, like
4150 (setting may not be changed) and
4152 meaning that the value is generated on-the-fly as necessary.
4153 Beside those known variables an infinite number of unknown, so-called
4155 variables, which are expected to be able to store values, may exist.
4156 .Bd -literal -offset indent
4158 ? varshow sendwait version-major foo bar
4159 "sendwait": (73) binary: set=1 (ENVIRON=0)
4160 "version-major": (192) value, read-only, virtual:\e
4161 set=1 (ENVIRON=0) value<14>
4162 "foo": (assembled) set=1 (ENVIRON=0) value<bar>
4163 "bar": (assembled) set=0 (ENVIRON=0) value<NULL>
4168 \*(OP Takes a message list and verifies each message.
4169 If a message is not a S/MIME signed message,
4170 verification will fail for it.
4171 The verification process checks if the message was signed using a valid
4173 if the message sender's email address matches one of those contained
4174 within the certificate,
4175 and if the message content has been altered.
4179 (v) Takes a message list and invokes the display editor on each message.
4180 Modified contents are discarded unless the
4186 (w) For conventional messages the body without all headers is written.
4187 The original message is never marked for deletion in the originating
4189 The output is decrypted and converted to its native format as necessary.
4190 If the output file exists, the text is appended.
4191 If a message is in MIME multipart format its first part is written to
4192 the specified file as for conventional messages, handling of the remains
4193 depends on the execution mode.
4194 No special handling of compressed files is performed.
4196 In interactive mode the user is consecutively asked for the filenames of
4197 the processed parts.
4198 For convience saving of each part may be skipped by giving an empty
4199 value, the same result as writing it to
4201 Shell piping the part content by specifying a leading vertical bar
4203 character for the filename is supported.
4204 Other user input is expanded as usually for folders, e.g., tilde
4205 expansion is performed, and contents of the destination file are
4206 overwritten if the file previously existed.
4208 \*(ID In non-interactive mode any part which does not specify a filename
4209 is ignored, and suspicious parts of filenames of the remaining parts are
4210 URL percent encoded (as via
4212 to prevent injection of malicious character sequences, resulting in
4213 a filename that will be written into the current directory.
4214 Existing files won't be overwritten, instead the part number or
4215 a dot are appended after a number sign
4217 to the name until file creation succeeds (or fails due to other
4227 \*(UA presents message headers in
4229 fuls as described under the
4232 Without arguments this command scrolls to the next window of messages,
4233 likewise if the argument is
4237 scrolls to the last,
4239 scrolls to the first, and
4244 A number argument prefixed by
4248 indicates that the window is calculated in relation to the current
4249 position, and a number without a prefix specifies an absolute position.
4255 but scrolls to the next or previous window that contains at least one
4264 .\" .Sh TILDE ESCAPES {{{
4267 Here is a summary of the tilde escapes,
4268 which are used to perform special functions when composing messages.
4269 Tilde escapes are only recognized at the beginning of lines.
4272 is somewhat of a misnomer since the actual escape character can be
4273 changed by adjusting the option
4276 .Bl -tag -width ".Ic __ filename"
4279 Insert the string of text in the message prefaced by a single
4281 (If the escape character has been changed,
4282 that character must be doubled
4283 in order to send it at the beginning of a line.)
4286 .It Ic ~! Ar command
4287 Execute the indicated shell
4289 then return to the message.
4293 Same effect as typing the end-of-file character.
4296 .It Ic ~: Ar \*(UA-command Ns \0or Ic ~_ Ar \*(UA-command
4297 Execute the given \*(UA command.
4298 Not all commands, however, are allowed.
4302 Write a summary of command escapes.
4305 .It Ic ~< Ar filename
4310 .It Ic ~<! Ar command
4312 is executed using the shell.
4313 Its standard output is inserted into the message.
4316 .It Ic ~@ Op Ar filename...
4317 With no arguments, edit the attachment list interactively.
4318 If an attachment's file name is left empty,
4319 that attachment is deleted from the list.
4320 When the end of the attachment list is reached,
4321 \*(UA will ask for further attachments until an empty name is given.
4322 If a given file name solely consists of the number sign
4324 followed by a valid message number of the currently active mailbox, then
4325 the given message is attached as a MIME
4327 and the rest of this section does not apply.
4329 If character set conversion has been compiled into \*(UA, then this mode
4330 gives the user the option to specify input and output character sets,
4331 unless the file extension indicates binary content, in which case \*(UA
4332 asks whether this step shall be skipped for the attachment in question.
4333 If not skipped, then the charset that succeeds to represent the
4334 attachment data will be used in the
4336 MIME parameter of the mail message:
4338 .Bl -bullet -compact
4340 If input and output character sets are specified, then the conversion is
4341 performed on the fly.
4342 The user will be asked repeatedly until the desired conversion succeeds.
4344 If only an output character set is specified, then the input is assumed
4347 charset and will be converted to the given output charset on the fly.
4348 The user will be asked repeatedly until the desired conversion succeeds.
4350 If no character sets are specified at all then the algorithm that is
4351 documented in the section
4352 .Sx "Character sets"
4353 is applied, but directly and on the fly.
4354 The user will be asked repeatedly until the desired conversion succeeds.
4356 Finally, if an input-, but no output character set is specified, then no
4357 conversion is ever performed, but the
4359 MIME parameter value will still be set to the user input.
4361 The character set selection loop can be left by typing
4363 i.e., causing an interrupt.
4364 .\" \*(OU next sentence
4365 Note that before \*(UA version 15.0 this terminates the entire
4366 current attachment selection, not only the character set selection.
4369 Without character set conversion support, \*(UA will ask for the input
4370 character set only, and it'll set the
4372 MIME parameter value to the given input, if any;
4373 if no user input is seen then the
4375 character set will be used for the parameter value instead.
4376 Note that the file extension check isn't performed in this mode, since
4377 no conversion will take place anyway.
4379 Note that in non-interactive mode, for reproduceabilities sake, there
4380 will always be two questions for each attachment, regardless of whether
4381 character set conversion is available and what the file extension is.
4382 The first asks for the filename, and the second asks for the input
4383 character set to be passed through to the corresponding MIME parameter;
4384 no conversion will be tried if there is input to the latter question,
4385 otherwise the usual conversion algorithm, as above, is applied.
4386 For message attachments, the answer to the second question is completely
4391 arguments are specified for the
4393 command they are treated as a comma separated list of files,
4394 which are all expanded and appended to the end of the attachment list.
4395 (Filenames with commas, or with leading or trailing whitespace can only
4396 be added via the command line or the first method.
4397 Message attachments can only be added via the first method;
4398 filenames which clash with message numbers can only be added via the
4399 command line or the second method.)
4400 In this mode the (text) attachments are assumed to be in
4402 encoding, and will be evaluated as documented in the section
4403 .Sx "Character sets" .
4407 Inserts the string contained in the
4410 .Ql Ic ~i Ns \0Sign ) .
4411 The escape sequences tabulator
4419 Inserts the string contained in the
4422 .Ql Ic ~i Ns \0sign ) .
4423 The escape sequences tabulator
4430 .It Ic ~b Ar name ...
4431 Add the given names to the list of blind carbon copy recipients.
4434 .It Ic ~c Ar name ...
4435 Add the given names to the list of carbon copy recipients.
4439 Read the file specified by the
4441 variable into the message.
4445 Invoke the text editor on the message collected so far.
4446 After the editing session is finished,
4447 the user may continue appending text to the message.
4450 .It Ic ~F Ar messages
4451 Read the named messages into the message being sent, including all
4452 message headers and MIME parts.
4453 If no messages are specified, read in the current message.
4456 .It Ic ~f Ar messages
4457 Read the named messages into the message being sent.
4458 If no messages are specified, read in the current message.
4462 lists are used to modify the message headers.
4463 For MIME multipart messages,
4464 only the first printable part is included.
4468 Edit the message header fields
4474 by typing each one in turn and allowing the user to edit the field.
4475 The default values for these fields originate from the
4476 .Va from , replyto , sender
4483 Edit the message header fields
4489 by typing each one in turn and allowing the user to edit the field.
4492 .It Ic ~i Ar variable
4493 Insert the value of the specified variable into the message,
4494 adding a newline character at the end.
4495 The message remains unaltered if the variable is unset or empty.
4496 The escape sequences tabulator
4503 .It Ic ~M Ar messages
4504 Read the named messages into the message being sent,
4507 If no messages are specified, read the current message.
4510 .It Ic ~m Ar messages
4511 Read the named messages into the message being sent,
4514 If no messages are specified, read the current message.
4518 lists are used to modify the message headers.
4519 For MIME multipart messages,
4520 only the first printable part is included.
4524 Print out the message collected so far,
4525 prefaced by the message header fields
4526 and followed by the attachment list, if any.
4530 Abort the message being sent,
4531 copying it to the file specified by the
4538 .It Ic ~R Ar filename
4539 Read the named file into the message, indented by
4543 .It Ic ~r Ar filename
4544 Read the named file into the message.
4548 Cause the named string to become the current subject field.
4551 .It Ic ~t Ar name ...
4552 Add the given name(s) to the direct recipient list.
4555 .It Ic ~U Ar messages
4556 Read in the given / current message(s) excluding all headers, indented by
4560 .It Ic ~u Ar messages
4561 Read in the given / current message(s), excluding all headers.
4565 Invoke an alternate editor (defined by the
4567 option) on the message collected so far.
4568 Usually, the alternate editor will be a screen editor.
4569 After the editor is quit,
4570 the user may resume appending text to the end of the message.
4573 .It Ic ~w Ar filename
4574 Write the message onto the named file.
4576 the message is appended to it.
4582 except that the message is not saved at all.
4585 .It Ic ~| Ar command
4586 Pipe the message through the specified filter command.
4587 If the command gives no output or terminates abnormally,
4588 retain the original text of the message.
4591 is often used as a rejustifying filter.
4596 .\" .Sh VARIABLE OPTIONS {{{
4597 .Sh "VARIABLE OPTIONS"
4599 Variables are controlled via
4603 commands; in general using
4605 can also be accomplished by prefixing a variable name with the string
4611 will have the same effect as
4613 Creation or editing of variables in an editor can also be achieved with
4616 will give more insight on the given variable(s), whereas
4618 will print a listing of all variables when called without arguments.
4619 Options are also implicitly inherited from the program
4621 and can be set explicitly via the command line option
4625 Different kind of options exist:
4626 binary options, which can only be in one of the two states
4630 as well as value options which have an assigned string value, for which
4631 proper quoting may be important upon assignment time.
4633 .\" .Ss "Initial settings" {{{
4634 .\" (Keep in sync: ./main.c:_startup(), ./nail.rc, ./nail.1:"Initial settings"!)
4635 .Ss "Initial Settings"
4637 The standard POSIX 2008/Cor 1-2013 mandates the following initial
4643 .Pf no Va autoprint ,
4657 .Pf no Va ignoreeof ,
4659 .Pf no Va keepsave ,
4661 .Pf no Va outfolder ,
4666 (note that \*(UA deviates from the standard by using
4670 special prompt escape results in
4672 being printed unless
4678 .Pf no Va sendwait ,
4687 Notes: \*(UA doesn't support the
4689 variable \(en use command line options or
4690 .Va sendmail-arguments
4691 to pass options through to a MTA.
4692 And the default global
4694 file (which is loaded unless the
4696 command line flag has been used or the
4697 .Ev NAIL_NO_SYSTEM_RC
4698 environment variable is set) bends those initial settings a bit, e.g.,
4704 to name a few, calls
4706 etc., and should thus be taken into account.
4709 .\" .Ss "Binary options" {{{
4710 .Ss "Binary options"
4712 .Bl -tag -width ".Va _utoprin_"
4714 .It Va add-file-recipients
4715 When file or pipe recipients have been specified,
4716 mention them in the corresponding address fields of the message instead
4717 of silently stripping them from their recipient list.
4718 By default such addressees are not mentioned.
4722 Causes only the local part to be evaluated
4723 when comparing addresses.
4727 Causes messages saved in
4729 to be appended to the end rather than prepended.
4730 This should always be set.
4734 .It Va ask Ns \0or Va asksub
4735 Causes \*(UA to prompt for the subject of each message sent.
4736 If the user responds with simply a newline,
4737 no subject field will be sent.
4741 Causes the prompts for
4745 lists to appear after the message has been edited.
4749 If set, \*(UA asks for files to attach at the end of each message, shall
4750 the list be found empty at that time.
4751 An empty line finalizes the list.
4755 Causes the user to be prompted for carbon copy recipients
4756 (at the end of each message if
4760 are set) shall the list be found empty (at that time).
4761 An empty line finalizes the list.
4765 Causes the user to be prompted for blind carbon copy
4766 recipients (at the end of each message if
4770 are set) shall the list be found empty (at that time).
4771 An empty line finalizes the list.
4775 \*(OP Causes the user to be prompted if the message is to be signed at
4776 the end of each message.
4779 variable is ignored when this variable is set.
4783 Causes threads to be collapsed automatically when threaded mode is
4790 Causes the delete command to behave like
4792 thus, after deleting a message the next one will be typed automatically.
4796 \*(OB Causes threaded mode (see the
4798 command) to be entered automatically when a folder is opened.
4800 .Ql autosort=thread .
4804 Enables the substitution of
4806 by the contents of the last command line in shell escapes.
4809 .It Va batch-exit-on-error
4810 If the batch mode has been enabled via the
4812 command line option, then this variable will be consulted whenever \*(UA
4813 completes one operation (returns to the command prompt); if it is set
4814 then \*(UA will terminate if the last operation generated an error.
4818 Causes automatic display of a header summary after executing a
4824 Sets some cosmetical features to traditional BSD style;
4825 has the same affect as setting
4827 and all other variables prefixed with
4829 it also changes the meaning of the \*(UA specific
4836 Changes the letters printed in the first column of a header summary
4837 to traditional BSD style.
4841 Changes the display of columns in a header summary to traditional BSD
4846 Changes some informational messages to traditional BSD style.
4852 field to appear immediately after the
4854 field in message headers and with the
4856 .Sx "TILDE ESCAPES" .
4860 Changes the output format of the
4862 command to traditional BSD style.
4865 .It Va colour-disable
4866 \*(OP Forcefully disable usage of colours.
4867 Also see the section
4868 .Sx "Coloured message display" .
4872 \*(OP Whether colour shall be used for output that is paged through
4874 Note that pagers may need special flags, e.g.,
4882 in order to support colours; therefore \*(UA will inspect the variable
4884 \(en if that starts with the string
4886 a non-existing environment variable
4893 will optionally be set to
4895 Also see the section
4896 .Sx "Coloured message display"
4901 Prints debugging messages and disables the actual delivery of messages.
4909 \*(OP When an IMAP mailbox is selected and this variable is set,
4910 no connection to the server is initiated.
4911 Instead, data is obtained from the local cache (see
4914 Mailboxes that are not present in the cache
4915 and messages that have not yet entirely been fetched from the server
4917 to fetch all messages in a mailbox at once,
4919 .No ` Ns Li copy * /dev/null Ns '
4920 can be used while still in connected mode.
4921 Changes that are made to IMAP mailboxes in disconnected mode are queued
4922 and committed later when a connection to that server is made.
4923 This procedure is not completely reliable since it cannot be guaranteed
4924 that the IMAP unique identifiers (UIDs) on the server still match the
4925 ones in the cache at that time.
4928 when this problem occurs.
4930 .It Va disconnected-USER@HOST
4931 The specified account is handled as described for the
4934 but other accounts are not affected.
4937 .It Va disposition-notification-send
4939 .Ql Disposition-Notification-To:
4940 header (RFC 3798) with the message.
4944 .\" TODO .It Va disposition-notification-send-HOST
4946 .\".Va disposition-notification-send
4947 .\" for SMTP accounts on a specific host.
4948 .\" TODO .It Va disposition-notification-send-USER@HOST
4950 .\".Va disposition-notification-send
4951 .\"for a specific account.
4955 When dot is set, a dot
4957 on a line by itself during message input from a terminal shall be
4958 treated as end-of-message (in addition to the normal end-of-file
4964 is ignored and using a dot is the only method to terminate input mode.
4967 .It Va dotlock-ignore-error
4968 \*(OP Synchronization of mailboxes which \*(UA treats as system
4969 mailboxes (see the command
4971 will be protected with so-called dotlock files\(emthe traditional mail
4972 spool file locking method\(emin addition to system file locking.
4973 Because \*(UA ships with a privilege-separated dotlock creation program
4974 that should always be able to create such a dotlock file there is no
4975 good reason to ignore dotlock file creation errors, and thus these are
4976 fatal unless this variable is set.
4980 If this variable is set then the editor is started automatically when
4981 a message is composed in interactive mode, as if the
4987 variable is implied for this automatically spawned editor session.
4991 When a message is edited while being composed,
4992 its header is included in the editable text.
5003 fields are accepted within the header, other fields are ignored.
5007 If the mailbox is empty \*(UA normally prints
5008 .Dq \&No mail for user
5009 and exits immediately.
5010 If this option is set \*(UA starts even with an empty mailbox.
5014 This option reverses the meanings of a set of reply commands,
5015 turning the lowercase variants, which by default address all recipients
5016 included in the header of a message
5017 .Pf ( Ic reply , respond , followup )
5018 into the uppercase variants, which by default address the sender only
5019 .Pf ( Ic Reply , Respond , Followup )
5022 .Ic replysender , respondsender , followupsender
5024 .Ic replyall , respondall , followupall
5025 are not affected by the current setting of
5031 .Ql Mail-Followup-To:
5032 header is generated when sending messages to known mailing lists.
5034 .Va followup-to-honour
5036 .Ic mlist , mlsubscribe , reply
5041 .It Va forward-as-attachment
5042 Original messages are normally sent as inline text with the
5045 and only the first part of a multipart message is included.
5046 With this option messages are sent as unmodified MIME
5048 attachments with all of their parts included.
5052 When replying to or forwarding a message \*(UA normally removes the
5053 comment and name parts of email addresses.
5054 If this variable is set such stripping is not performed,
5055 and comments, names etc. are retained.
5059 Causes the header summary to be written at startup and after commands
5060 that affect the number of messages or the order of messages in the
5061 current folder; enabled by default.
5062 The command line option
5068 .It Va history-gabby
5069 \*(OP Add more entries to the history as is normally done.
5072 .It Va history-gabby-persist
5073 \*(OP \*(UAs own NCL will not save the additional (gabby) history
5074 entries in persistent storage unless this variable is also set.
5080 This option is used to hold messages in the system mailbox by default.
5084 \*(OP Can be used to turn off the automatic conversion of domain names
5085 according to the rules of IDNA (internationalized domain names for
5087 Since the IDNA code assumes that domain names are specified with the
5089 character set, an UTF-8 locale charset is required to represent all
5090 possible international domain names (before conversion, that is).
5094 Ignore interrupt signals from the terminal while entering messages;
5095 instead echo them as
5097 characters and discard the current line.
5101 Ignore end-of-file conditions
5102 .Pf ( Ql control-D ) ,
5103 on message input, which instead can be terminated only by entering a
5106 on a line by itself or by using the
5108 .Sx "TILDE ESCAPES" .
5109 This option also applies to \*(UA command mode.
5111 .Mx Va imap-use-starttls
5112 .It Va imap-use-starttls-USER@HOST , imap-use-starttls-HOST , imap-use-starttls
5113 \*(OP Causes \*(UA to issue a `STARTTLS' command to make an unencrypted
5114 IMAP session SSL/TLS encrypted.
5115 This functionality is not supported by all servers,
5116 and is not used if the session is already encrypted by the IMAPS method.
5120 If set, an empty mailbox file is not removed.
5121 This may improve the interoperability with other mail user agents
5122 when using a common folder directory, and prevents malicious users
5123 from creating fake mailboxes in a world-writable spool directory.
5124 Note this only applies to local regular (MBOX) files, other mailbox
5125 types will never be removed.
5129 When a message is saved it is usually discarded from the originating
5130 folder when \*(UA is quit.
5131 Setting this option causes all saved message to be retained.
5134 .It Va line-editor-disable
5135 Turn off any enhanced command line editing capabilities (see
5136 .Sx "Command line editor"
5141 When a message is replied to and this variable is set,
5142 it is marked as having been answered.
5143 This mark has no technical meaning in the mail system;
5144 it just causes messages to be marked in the header summary,
5145 and makes them specially addressable.
5148 .It Va message-id-disable
5149 By setting this option the generation of
5151 can be completely suppressed, effectively leaving this task up to the
5152 mail-transfer-agent (MTA) or the SMTP server.
5153 (According to RFC 5321 your SMTP server is not required to add this
5154 field by itself, so you should ensure that it accepts messages without a
5161 expansion contains the sender, the sender is removed from the expansion.
5162 Setting this option suppresses these removals.
5167 option to be passed to mail-transfer-agents (MTAs);
5168 though most of the modern MTAs don't (no longer) document this flag, no
5169 MTA is known which doesn't support it (for historical compatibility).
5172 .It Va mime-allow-text-controls
5173 When sending messages, each part of the message is MIME-inspected in
5174 order to classify the
5177 .Ql Content-Transfer-Encoding:
5180 that is required to send this part over mail transport, i.e.,
5181 a computation rather similar to what the
5183 command produces when used with the
5187 This classification however treats text files which are encoded in
5188 UTF-16 (seen for HTML files) and similar character sets as binary
5189 octet-streams, forcefully changing any
5194 .Ql application/octet-stream :
5195 If that actually happens a yet unset charset MIME parameter is set to
5197 effectively making it impossible for the receiving MUA to automatically
5198 interpret the contents of the part.
5200 If this option is set, and the data was unambiguously identified as text
5201 data at first glance (by a
5205 file extension), then the original
5207 will not be overwritten.
5210 .It Va netrc-lookup-USER@HOST , netrc-lookup-HOST , netrc-lookup
5211 \*(IN \*(OP Used to control usage of the users
5213 file for lookup of account credentials, as documented in the section
5214 .Sx "On URL syntax and credential lookup"
5218 .Sx "The .netrc file"
5219 documents the file format.
5223 Causes the filename given in the
5226 and the sender-based filenames for the
5230 commands to be interpreted relative to the directory given in the
5232 variable rather than to the current directory,
5233 unless it is set to an absolute pathname.
5237 If set, each message the
5239 command prints out is followed by a formfeed character
5244 Send messages to the
5246 command without performing MIME and character set conversions.
5249 .Mx Va pop3-bulk-load
5250 .It Va pop3-bulk-load-USER@HOST , pop3-bulk-load-HOST , pop3-bulk-load
5251 \*(OP When accessing a POP3 server \*(UA loads the headers of the
5252 messages, and only requests the message bodies on user request.
5253 For the POP3 protocol this means that the message headers will be
5255 If this option is set then \*(UA will download only complete messages
5256 from the given POP3 server(s) instead.
5259 .It Va pop3-no-apop-USER@HOST , pop3-no-apop-HOST , pop3-no-apop
5260 \*(OP Unless this variable is set the
5262 authentication method will be used when connecting to a POP3 server that
5266 is that the password is not sent in clear text over the wire and that
5267 only a single packet is sent for the user/password tuple.
5269 .Va pop3-no-apop-HOST
5272 .Mx Va pop3-use-starttls
5273 .It Va pop3-use-starttls-USER@HOST , pop3-use-starttls-HOST , pop3-use-starttls
5274 \*(OP Causes \*(UA to issue a
5276 command to make an unencrypted POP3 session SSL/TLS encrypted.
5277 This functionality is not supported by all servers,
5278 and is not used if the session is already encrypted by the POP3S method.
5280 .Va pop3-use-starttls-HOST
5284 .It Va print-all-chars
5285 This option causes all characters to be considered printable.
5286 It is only effective if given in a startup file.
5287 With this option set some character sequences in messages may put the
5288 user's terminal in an undefined state when printed;
5289 it should only be used as a last resort if no working system locale can
5293 .It Va print-alternatives
5294 When a MIME message part of type
5295 .Ql multipart/alternative
5296 is displayed and it contains a subpart of type
5298 other parts are normally discarded.
5299 Setting this variable causes all subparts to be displayed,
5300 just as if the surrounding part was of type
5301 .Ql multipart/mixed .
5305 Suppresses the printing of the version when first invoked.
5308 .It Va quote-as-attachment
5309 If this is set, then the original message is added in its entirety as a
5311 MIME attachment when replying to a message.
5312 Note this works regardless of the setting of
5316 .It Va recipients-in-cc
5317 On group replies, specify only the sender of the original mail in
5319 and mention the other recipients in the secondary
5321 By default all recipients of the original mail will be addressed via
5325 .It Va record-resent
5326 If both this variable and the
5333 commands save messages to the
5335 folder as it is normally only done for newly composed messages.
5338 .It Va reply-in-same-charset
5339 If this variable is set \*(UA first tries to use the same character set
5340 of the original message for replies.
5341 If this fails, the mechanism described in
5342 .Sx "Character sets"
5343 is evaluated as usual.
5346 .It Va rfc822-body-from_
5347 This variable can be used to force displaying a so-called
5349 line for messages that are embedded into an envelope mail via the
5351 MIME mechanism, for more visual convenience.
5355 Enable saving of (partial) messages in
5357 upon interrupt or delivery error.
5360 .It Va searchheaders
5361 Expand message-list specifiers in the form
5363 to all messages containing the substring
5367 The string search is case insensitive.
5370 .It Va sendcharsets-else-ttycharset
5371 \*(OP If this variable is set, but
5373 is not, then \*(UA acts as if
5375 had been set to the value of the variable
5377 In effect this combination passes through the message data in the
5378 character set of the current locale (given that
5380 hasn't been set manually), i.e., without converting it to the
5382 fallback character set.
5383 Thus, mail message text will be in ISO-8859-1 encoding when send from
5384 within a ISO-8859-1 locale, and in UTF-8 encoding when send from within
5386 If no character set conversion capabilities are available in \*(UA then
5387 the only supported character set is
5390 .It Va sendmail-no-default-arguments
5391 Unless this option is set \*(UA will pass some well known
5392 standard command line options to the defined
5394 program, see there for more.
5398 When sending a message wait until the MTA (including the builtin SMTP
5399 one) exits before accepting further commands.
5401 with this variable set errors reported by the MTA will be recognizable!
5402 If the MTA returns a non-zero exit status,
5403 the exit status of \*(ua will also be non-zero.
5407 Setting this option causes \*(UA to start at the last message instead of
5408 the first one when opening a mail folder.
5412 Causes \*(UA to use the sender's real name instead of the plain address
5413 in the header field summary and in message specifications.
5417 Causes the recipient of the message to be shown in the header summary
5418 if the message was sent by the user.
5421 .It Va skipemptybody
5422 If an outgoing message does not contain any text in its first or only
5424 do not send it but discard it silently (see also the command line option
5428 .It Va smime-force-encryption
5429 \*(OP Causes \*(UA to refuse sending unencrypted messages.
5433 \*(OP S/MIME sign outgoing messages with the user's private key and
5434 include the user's certificate as a MIME attachment.
5435 Signing a message enables a recipient to verify that the sender used
5436 a valid certificate,
5437 that the email addresses in the certificate match those in the message
5438 header and that the message content has not been altered.
5439 It does not change the message text,
5440 and people will be able to read the message as usual.
5442 .Va smime-sign-cert , smime-sign-include-certs
5444 .Va smime-sign-message-digest .
5447 .It Va smime-no-default-ca
5448 \*(OP Don't load default CA locations when verifying S/MIME signed
5451 .Mx Va smtp-use-starttls
5452 .It Va smtp-use-starttls-USER@HOST , smtp-use-starttls-HOST , smtp-use-starttls
5453 \*(OP Causes \*(UA to issue a
5455 command to make an SMTP session SSL/TLS encrypted, i.e., to enable
5456 transport layer security.
5459 .It Va ssl-no-default-ca
5460 \*(OP Don't load default CA locations to verify SSL/TLS server
5465 \*(OP If terminal capability queries are supported and this option is
5466 set then \*(UA will try to switch to the
5467 .Dq alternate screen
5468 when in interactive mode, so that the terminal will go back to the
5469 normal screen, leaving all the text there intact, when \*(UA exits.
5471 even when supported for this to produce appealing results the used
5473 and possibly configured
5474 .Va pipe-TYPE/SUBTYPE
5475 applications that take control over the terminal need to have
5476 corresponding support too, e.g., the
5478 pager should be driven with the
5483 .It Va keep-content-length
5484 When (editing messages and) writing
5486 mailbox files \*(UA can be told to keep the
5490 header fields that some MUAs generate by setting this variable.
5491 Since \*(UA does neither use nor update these non-standardized header
5492 fields (which in itself shows one of their conceptual problems),
5493 stripping them should increase interoperability in between MUAs that
5494 work with with same mailbox files.
5495 Note that, if this is not set but
5496 .Va writebackedited ,
5497 as below, is, a possibly performed automatic stripping of these header
5498 fields already marks the message as being modified.
5502 Setting this option enables upward compatibility with \*(UA version 15.0
5503 in respect to which configuration options are available and how they are
5505 This manual uses \*(IN and \*(OU to refer to the new and the old way of
5506 doing things, respectively.
5510 Setting this option, also controllable via the command line option
5512 causes \*(UA to be more verbose, so that, e.g., certificate chains will
5513 be displayed on the users terminal.
5514 Setting this binary option twice increases the level of verbosity, in
5515 which case even details of the actual message delivery and protocol
5516 conversations are shown.
5519 is sufficient to disable verbosity as such.
5522 .It Va writebackedited
5523 If this variable is set messages modified using the
5527 commands are written back to the current folder when it is quit;
5528 it is only honoured for writable folders in MBOX format, though.
5529 Note that the editor will be pointed to the raw message content in that
5530 case, i.e., neither MIME decoding nor decryption will have been
5531 performed, and proper RFC 4155
5533 quoting of newly added or edited content is also left as an excercise to
5538 .\" .Ss "Value options" {{{
5541 Options with values that are generally treated as strings.
5542 To embed whitespace (space and tabulator) in a value it either needs to
5543 be escaped with a backslash character, or the entire value must be
5544 enclosed in (double or single) quotation marks;
5545 To use quotation marks identical to those used to enclose the value,
5546 escape them with a backslash character.
5547 The backslash character has no special meaning except in these cases.
5549 .Bd -literal -offset indent
5550 set 1=val\e one 2="val two" 3='val "three"' 4='val \e'four\e''
5556 Booleans are special string values that must either be set to decimal
5557 integers (in which case
5561 and any other value is true) or to any of
5566 for a false boolean and
5571 for a true boolean; matching is performed case-insensitively.
5572 And there exists a special kind of boolean, the
5574 this is expected to either name a boolean or one of the strings
5580 followed by a valid boolean, case-insensitively);
5581 if one of the latter is set then in interactive mode the user will be
5582 prompted with the default value (also used for empty user input) set to
5583 the given boolean, whereas in non-interactive the given default will
5586 .Bl -tag -width ".It Va _utoprin_"
5587 .Mx Va agent-shell-lookup
5588 .It Va agent-shell-lookup-USER@HOST , agent-shell-lookup-HOST , \
5590 \*(IN \*(OP Account passwords can be fetched via an external agent
5591 program in order to permit encrypted password storage \(en see
5592 .Sx "On URL syntax and credential lookup"
5593 for more on credential lookup.
5594 If this is set then the content is interpreted as a shell command the
5595 output of which (with newline characters removed) is treated as the
5596 account password shall the command succeed (and have produced non-empty
5597 non-newline output); e.g., via
5599 .Bd -literal -offset indent
5600 $ echo PASSWORD > .pass
5602 $ eval `gpg-agent --daemon \e
5603 --pinentry-program=/usr/bin/pinentry-curses \e
5604 --max-cache-ttl 99999 --default-cache-ttl 99999`
5605 $ echo 'set agent-shell-lookup="gpg -d .pass.gpg"' \e
5609 A couple of environment variables will be set for the agent:
5611 .Bl -tag -compact -width ".It Ev _AIL_TMPDIR[337]"
5613 The temporary directory that \*(UA uses.
5614 Usually identical to
5616 but guaranteed to be set and usable by child processes;
5617 to ensure the latter condition for
5623 for which the password is looked up.
5624 .It Ev NAIL_USER_ENC
5625 The URL percent-encoded variant of
5628 The plain machine hostname of the user account.
5629 .It Ev NAIL_HOST_PORT
5632 (hostname possibly including port) of the user account.
5637 A sequence of characters to print in the
5641 as shown in the header display; each for one type of messages (see
5642 .Sx "Message states" ) ,
5643 with the default being
5646 .Ql NU\ \ *HMFAT+\-$~
5651 environment variable are set, in the following order:
5653 .Bl -tag -compact -offset indent -width ".It Ql _"
5675 start of a collapsed thread.
5681 classified as possible spam.
5686 Specifies a list of recipients to which a blind carbon copy of each
5687 outgoing message will be sent automatically.
5691 Specifies a list of recipients to which a carbon copy of each outgoing
5692 message will be sent automatically.
5696 Causes sorted mode (see the
5698 command) to be entered automatically with the value of this option as
5699 sorting method when a folder is opened.
5703 The value that should appear in the
5707 MIME header fields when no character set conversion of the message data
5709 This defaults to US-ASCII, and the chosen character set should be
5710 US-ASCII compatible.
5714 \*(OP The default 8-bit character set that is used as an implicit last
5715 member of the variable
5717 This defaults to UTF-8.
5718 If no character set conversion capabilities are available in \*(UA then
5719 the only supported character set is
5721 Refer to the section
5722 .Sx "Character sets"
5723 for the complete picture of character set conversion in \*(UA.
5726 .It Va charset-unknown-8bit
5727 \*(OP RFC 1428 specifies conditions when internet mail gateways shall
5729 the content of a mail message by using a character set with the name
5731 Because of the unclassified nature of this character set \*(UA will not
5732 be capable to convert this character set to any other character set.
5733 If this variable is set any message part which uses the character set
5735 is assumed to really be in the character set given in the value,
5736 otherwise the (final) value of
5738 is used for this purpose.
5742 The default value for the
5748 \*(OP The colour specification for so-called
5752 .Sx "Coloured message display"
5753 for the format of the value.
5756 .It Va colour-header
5757 \*(OP The colour specification for header lines.
5760 .It Va colour-msginfo
5761 \*(OP The colour specification for the introductional message info line.
5764 .It Va colour-partinfo
5765 \*(OP The colour specification for MIME part info lines.
5769 \*(OP A comma-separated list of
5771 inals for which coloured message display can be used.
5772 Entries only need to be added if the string
5774 isn't part of the terminal name itself; the default value is
5776 .Dl cons25,linux,rxvt,rxvt-unicode,\:screen,\:sun,\:vt100,\:vt220,\:\
5780 .It Va colour-uheader
5781 \*(OP The colour specification for those header lines that have been
5783 .Va colour-user-headers
5786 .Sx "Coloured message display" .
5789 .It Va colour-user-headers
5790 A comma separated list of (case-insensitive) header names which should
5791 be colourized with the alternative
5794 The default value is
5799 In a(n interactive) terminal session, then if this valued option is set
5800 it'll be used as a threshold to determine how many lines the given
5801 output has to span before it will be displayed via the configured
5805 can be forced by setting this to the value
5807 setting it without a value will deduce the current height of the
5808 terminal screen to compute the treshold (see
5815 The date in a header summary is normally the date of the mailbox
5817 line of the message.
5818 If this variable is set, then the date as given in the
5820 field is used, converted to local time.
5821 It is possible to control the display of the date by assigning a value,
5824 function will be used to format the date accordingly.
5825 Please read your system manual for the available formats.
5828 format should not be used, because \*(UA doesn't take embedded newlines
5829 into account when calculating how many lines fit onto the screen.
5832 .It Va datefield-markout-older
5833 This option, when set in addition to
5837 messages (concept is rather comparable to the
5839 option of the POSIX utility
5841 The content interpretation is identical to
5846 Suggestion for the MIME encoding to use in outgoing text messages
5848 Valid values are the default
5849 .Ql quoted-printable ,
5854 may cause problems when transferring mail messages over channels that
5855 are not ESMTP (RFC 1869) compliant.
5856 If there is no need to encode a message,
5858 transfer mode is always used regardless of this variable.
5859 Binary data is always encoded as
5864 If defined, the first character of this option
5865 gives the character to use in place of
5868 .Sx "TILDE ESCAPES" .
5872 If not set then file and command pipeline targets are not allowed,
5873 and any such address will be filtered out, giving a warning message.
5874 If set without a value then all possible recipient address
5875 specifications will be accepted \(en see the section
5878 To accept them, but only in interactive mode, or when tilde commands
5879 were enabled explicitly by using one of the command line options
5883 set this to the (case-insensitive) value
5885 (note right now this is actually like setting
5886 .Ql restrict,-all,+name,+addr ) .
5888 In fact the value is interpreted as a comma-separated list of values.
5891 then the existence of disallowed specifications is treated as a hard
5892 send error instead of only filtering them out.
5893 The remaining values specify whether a specific type of recipient
5894 address specification is allowed (optionally indicated by a plus sign
5896 prefix) or disallowed (prefixed with a hyphen
5900 addresses all possible address specifications,
5904 command pipeline targets,
5906 plain user names and (MTA) aliases (\*(OB
5908 may be used as an alternative syntax to
5913 These kind of values are interpreted in the given order, so that
5914 .Ql restrict,\:fail,\:+file,\:-all,\:+addr
5915 will cause hard errors for any non-network address recipient address
5916 unless \*(UA is in interactive mode or has been started with the
5920 command line option; in the latter case(s) any address may be used, then.
5924 Unless this variable is set additional mail-transfer-agent (MTA)
5925 arguments from the command line, as can be given after a
5927 separator, are ignored due to safety reasons.
5928 However, if set to the special value
5930 then the presence of additional MTA arguments is treated as a hard
5931 error that causes \*(UA to exit with failure status.
5932 A lesser strict variant is the otherwise identical
5934 which does accept such arguments in interactive mode, or if tilde
5935 commands were enabled explicitly by using one of the command line options
5942 \*(RO Information on the features compiled into \*(UA \(en the content
5943 of this variable is identical to the output of the command
5948 .It Va file-hook-load-EXTENSION , file-hook-save-EXTENSION
5949 It is possible to install file hooks which will be used by the
5951 command in order to be able to transparently handle (through an
5952 intermediate temporary file) files with specific
5954 s: the variable values can include shell snippets and are expected to
5955 write data to standard output / read data from standard input,
5957 \*(ID The variables may not be changed while there is a mailbox
5959 .Bd -literal -offset indent
5960 set file-hook-load-xy='echo >&2 XY-LOAD; gzip -cd' \e
5961 file-hook-save-xy='echo >&2 XY-SAVE; gzip -c' \e
5962 record=+null-sent.xy
5967 The name of the directory to use for storing folders of messages.
5968 All folder names that begin with
5970 refer to files below it.
5971 The same special conventions as documented for the
5973 command may be used when specifying a new value for
5975 but be aware that the expansion is fully performed immediately.
5976 E.g., if the expanded name refers to an IMAP account, all names that
5977 begin with `+' refer to IMAP mailboxes below the
5981 Note: for IMAP it makes a difference whether
5983 ends with a directory separator solidus or not in respect to the
5984 automatic append of `INBOX' strings.
5985 Ssome IMAP servers do not accept the creation of mailboxes in
5986 the hierarchy base, but require that they are created as subfolders of
5987 `INBOX' \(en with such servers a folder name of the form
5989 .Dl imaps://mylogin@imap.myisp.example/INBOX.
5991 should be used (the last character is the server's hierarchy delimiter).
5992 Folder names prefixed by `+' will then refer to folders below `INBOX',
5993 while folder names prefixed by `@' refer to folders below the hierarchy
5997 namespace command for a method to detect the appropriate prefix and
6002 When a folder is opened and this variable is set,
6003 the macro corresponding to the value of this variable is executed.
6004 The macro is also invoked when new mail arrives,
6005 but message lists for commands executed from the macro
6006 only include newly arrived messages then.
6009 are activated in a folder hook, then the covered settings will be
6010 reverted once the folder is left again.
6013 .It Va folder-hook-FOLDER
6018 Unlike other folder specifications, the fully expanded name of a folder,
6019 without metacharacters, is used to avoid ambiguities.
6020 However, if the mailbox resides under
6024 specification is tried in addition, e.g., if
6028 (and thus relative to the user's home directory) then
6029 .Pa /home/usr1/mail/sent
6031 .Ql folder-hook-/home/usr1/mail/sent
6032 first, but then followed by
6033 .Ql folder-hook-+sent .
6036 .It Va followup-to-honour
6038 .Ql Mail-Followup-To:
6039 header is honoured when group-replying to a message via
6043 This is a quadoption; if set without a value it defaults to
6054 The address (or a list of addresses) to put into the
6056 field of the message header, quoting RFC 5322:
6057 the author(s) of the message, that is, the mailbox(es) of the person(s)
6058 or system(s) responsible for the writing of the message.
6059 If replying to messages these addresses are handled as if they were in
6063 If the machine's hostname is not valid at the Internet (for example at
6064 a dialup machine) then either this variable or
6069 adds even more fine-tuning capabilities),
6073 contains more than one address,
6076 variable is required (according to the standard RFC 5322).
6080 The string to print before the text of a message with the
6084 .Va forward-as-attachment
6087 .Dq -------- Original Message --------
6088 if unset; No heading is printed if it is set to the empty string.
6092 A format string to use for the header summary,
6098 introduces a format specifier that may be followed by a number
6099 indicating the field width;
6100 If the (possibly implicitly implied) field width is negative, the field
6101 is to be left-aligned.
6102 Valid format specifiers are:
6104 .Bl -tag -compact -offset indent -width "_%%_"
6106 A plain percent character.
6108 A space character but for the current message, for which it expands to
6111 A space character but for the current message, for which it expands to
6114 \*(OP The spam score of the message, as has been classified via the
6117 Prints only a replacement character if there is no spam support.
6119 Message attribute character (status flag); the actual content can be
6123 The date when the message was received.
6125 The indenting level in threaded mode.
6127 The address of the message sender.
6129 The message thread structure.
6130 (Note that this format doesn't support a field width.)
6132 The number of lines of the message.
6136 The number of octets (bytes) in the message.
6138 Message subject (if any).
6140 Message subject (if any) in double quotes.
6142 Message recipient flags: is the addressee of the message a known or
6143 subscribed mailing list \(en see
6148 The position in threaded/sorted order.
6152 .Ql %>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s ,
6154 .Ql %>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S
6164 .It Va headline-bidi
6165 Bidirectional text requires special treatment when displaying headers,
6166 because numbers (in dates or for file sizes etc.) will not affect the
6167 current text direction, in effect resulting in ugly line layouts when
6168 arabic or other right-to-left text is to be displayed.
6169 On the other hand only a minority of terminals is capable to correctly
6170 handle direction changes, so that user interaction is necessary for
6172 Note that extended host system support is required nonetheless, e.g.,
6173 detection of the terminal character set is one precondition;
6174 and this feature only works in an Unicode (i.e., UTF-8) locale.
6176 In general setting this variable will cause \*(UA to encapsulate text
6177 fields that may occur when printing
6179 (and some other fields, like dynamic expansions in
6181 with special Unicode control sequences;
6182 it is possible to fine-tune the terminal support level by assigning
6184 no value (or any value other than
6189 will make \*(UA assume that the terminal is capable to properly deal
6190 with Unicode version 6.3, in which case text is embedded in a pair of
6191 U+2068 (FIRST STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE)
6193 In addition no space on the line is reserved for these characters.
6195 Weaker support is chosen by using the value
6197 (Unicode 6.3, but reserve the room of two spaces for writing the control
6198 sequences onto the line).
6203 select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT MARK); the latter
6204 again reserves room for two spaces in addition.
6208 Use this string as hostname when expanding local addresses instead of
6209 the value obtained from
6220 transport is not used then it is normally the responsibility of the MTA
6221 to create these fields, \*(IN in conjunction with
6225 also influences the results;
6226 you should produce some test messages with the desired combination of
6234 .It Va imap-auth-USER@HOST , imap-auth
6235 \*(OP Sets the IMAP authentication method.
6236 Valid values are `login' for the usual password-based authentication
6238 `cram-md5', which is a password-based authentication that does not send
6239 the password over the network in clear text,
6240 and `gssapi' for GSS-API based authentication.
6244 \*(OP Enables caching of IMAP mailboxes.
6245 The value of this variable must point to a directory that is either
6246 existent or can be created by \*(UA.
6247 All contents of the cache can be deleted by \*(UA at any time;
6248 it is not safe to make assumptions about them.
6251 .It Va imap-delim-USER@HOST , imap-delim-HOST , imap-delim
6252 \*(OP The hierarchy separator used by the IMAP server.
6253 Whenever an IMAP path is specified it will undergo normalization.
6254 One of the normalization steps is the squeeze and adjustment of
6255 hierarchy separators.
6256 If this variable is set, any occurrence of any character of the given
6257 value that exists in the path will be replaced by the first member of
6258 the value; an empty value will cause the default to be used, it is
6260 If not set, we will reuse the first hierarchy separator character that
6261 is discovered in a user-given mailbox name.
6263 .Mx Va imap-keepalive
6264 .It Va imap-keepalive-USER@HOST , imap-keepalive-HOST , imap-keepalive
6265 \*(OP IMAP servers may close the connection after a period of
6266 inactivity; the standard requires this to be at least 30 minutes,
6267 but practical experience may vary.
6268 Setting this variable to a numeric `value' greater than 0 causes
6269 a `NOOP' command to be sent each `value' seconds if no other operation
6273 .It Va imap-list-depth
6274 \*(OP When retrieving the list of folders on an IMAP server, the
6276 command stops after it has reached a certain depth to avoid possible
6278 The value of this variable sets the maximum depth allowed.
6280 If the folder separator on the current IMAP server is a slash `/',
6281 this variable has no effect and the
6283 command does not descend to subfolders.
6287 If this is set it will be used for expansions of
6292 \*(ID IMAP users may set this to the empty string to force bypassing the
6295 The value supports a subset of filename expansions itself.
6306 option for indenting messages,
6307 in place of the normal tabulator character
6309 which is the default.
6310 Be sure to quote the value if it contains spaces or tabs.
6313 .It Va line-editor-cursor-right
6314 \*(OP If the builtin command line editor is used, actions which are
6315 based on rightwise movement may not work on some terminals.
6316 If you encounter such problems, set this variable to the terminal
6317 control sequence that is necessary to move the cursor one column to the
6321 which should work for most terminals.
6328 and other control character have to be written as shell-style escape
6335 .It Va mime-counter-evidence
6338 field is used to decide how to handle MIME parts.
6339 Some MUAs however don't use
6341 or a similar mechanism to correctly classify content, but simply specify
6342 .Ql application/octet-stream ,
6343 even for plain text attachments like
6345 If this variable is set then \*(UA will try to classify such MIME
6346 message parts on its own, if possible, and through their file name.
6347 This variable can also be given a non-empty value, in which case the
6348 value is expected to be a number, actually a carrier of bits.
6349 Creating the bit-carrying number is a simple addition:
6350 .Bd -literal -offset indent
6351 ? !echo Value should be set to $((2 + 4))
6352 Value should be set to 6
6355 .Bl -bullet -compact
6357 If bit two is set (2) then the detected
6359 content-type will be carried along with the message and be used for
6361 .Va pipe-TYPE/SUBTYPE
6362 is responsible for the MIME part, shall that question arise;
6363 when displaying such a MIME part the part-info will indicate the
6364 overridden content-type by showing a plus-sign
6367 If bit three is set (4) then the counter-evidence is always produced
6368 and a positive result will be used as the MIME type, even forcefully
6369 overriding the parts given MIME type.
6371 .\"If bit four is set (8) then as a last resort the content of
6372 .\".Ql application/octet-stream
6373 .\"parts will be inspected, so that data that looks like (english) plain
6374 .\"text can be treated as such.
6378 .It Va mimetypes-load-control
6379 This option can be used to control which of the
6381 databases are loaded by \*(UA, as furtherly described in the section
6382 .Sx "The mime.types files" .
6385 is part of the option value, then the user's personal
6387 file will be loaded (if it exists); likewise the letter
6389 controls loading of the system wide
6390 .Pa /etc/mime.types ;
6391 the user file is loaded first, letter matching is case-insensitive.
6392 If this option is not set \*(UA will try to load both files instead.
6393 Incorporation of the \*(UA-builtin MIME types cannot be suppressed,
6394 but they will be matched last.
6396 More sources can be specified by using a different syntax: if the
6397 value string contains an equals sign
6399 then it is instead parsed as a comma-separated list of the described
6402 pairs; the given filenames will be expanded and loaded, and their
6403 content may use the extended syntax that is described in the section
6404 .Sx "The mime.types files" .
6407 .It Va NAIL_EXTRA_RC
6408 The name of an optional startup file to be read after
6410 This variable has an effect only if it is set in
6414 it is not imported from the environment in order to honour
6415 .Ql MAILRC=/dev/null Ns /
6418 Use this file for commands that are not understood by other POSIX
6424 A string to put at the beginning of each new message.
6425 The escape sequences tabulator
6432 .It Va NAIL_HISTFILE
6433 \*(OP If a command line editor is available then this can be set to
6434 name the (expandable) path of the location of a permanent history file.
6437 .It Va NAIL_HISTSIZE
6438 \*(OP If a command line editor is available this value restricts the
6439 amount of history entries that are saved into a set and valid
6441 A value of less than 0 disables this feature;
6442 note that loading and incorporation of
6444 upon program startup can also be suppressed by doing this.
6445 An unset or invalid value, or 0, causes a default value to be used.
6446 Dependent on the available command line editor this will also define the
6447 number of history entries in memory;
6448 it is also editor-specific whether runtime updates of this value will be
6453 A string to put at the end of each new message.
6454 The escape sequences tabulator
6462 If this variable has the value
6464 newly created local folders will be in Maildir format.
6468 Checks for new mail in the current folder each time the prompt is
6470 For IMAP mailboxes the server is then polled for new mail,
6471 which may result in delayed operation if the connection to the server is
6473 A Maildir folder must be re-scanned to determine if new mail has arrived.
6475 If this variable is set to the special value
6477 an IMAP server is not actively asked for new mail, but new mail may
6478 still be detected and announced with any other IMAP command that is sent
6480 In either case the IMAP server may send notifications about messages
6481 that have been deleted on the server by another process or client.
6483 .Dq Expunged X messages
6484 is printed regardless of this variable, and message numbers may have
6487 If this variable is set to the special value
6489 then a Maildir folder will not be rescanned completely, but only
6490 timestamp changes are detected.
6494 The value to put into the
6496 field of the message header.
6499 .It Va password-USER@HOST , password-HOST , password
6500 \*(IN Variable chain that sets a password, which is used in case none has
6501 been given in the protocol and account-specific URL;
6502 as a last resort \*(UA will ask for a password on the user's terminal if
6503 the authentication method requires a password.
6504 Specifying passwords in a startup file is generally a security risk;
6505 the file should be readable by the invoking user only.
6507 .It Va password-USER@HOST
6508 \*(OU (see the chain above for \*(IN)
6509 Set the password for
6513 If no such variable is defined for a host,
6514 the user will be asked for a password on standard input.
6515 Specifying passwords in a startup file is generally a security risk;
6516 the file should be readable by the invoking user only.
6519 .It Va pipe-TYPE/SUBTYPE
6520 When a MIME message part of type
6522 (normalized to lowercase) is displayed or quoted,
6523 its text is filtered through the value of this variable interpreted as
6527 can be used to force interpretation of the message part as plain text, e.g.,
6528 .Ql set pipe-application/pgp-signature=@
6529 will henceforth treat signatures as plain text and display them "as is".
6530 (The same can also be achieved, in a more useful context, by using the
6532 command in conjunction with a type marker.)
6534 Also, if a shell command is prefixed with
6536 then the command will only be used to prepare the MIME message part if
6537 the message is displayed by itself, but not when multiple messages are
6540 Finally, if a shell command is prefixed with
6542 then, in addition to what has been described for the plain
6544 shell command prefix, the command will be run asynchronously, i.e.,
6545 without blocking \*(UA, which may be a handy way to display a, e.g., PDF
6546 file while also continuing to read the mail message.
6547 Some information about the MIME part to be displayed is embedded into
6548 the environment of the shell command:
6550 .Bl -tag -compact -width ".It Ev _AIL__ILENAME__ENERATED"
6553 The temporary directory that \*(UA uses.
6554 Usually identical to
6556 but guaranteed to be set and usable by child processes;
6557 to ensure the latter condition for
6561 .It Ev NAIL_FILENAME
6562 The filename, if any is set, the empty string otherwise.
6564 .It Ev NAIL_FILENAME_GENERATED
6568 The MIME content-type of the part, if known, the empty string otherwise.
6570 .It Ev NAIL_CONTENT_EVIDENCE
6572 .Va mime-counter-evidence
6573 includes the carry-around-bit (2), then this will be set to the detected
6574 MIME content-type; not only then identical to
6575 .Ev \&\&NAIL_CONTENT
6580 .It Va pipe-EXTENSION
6581 This is identical to
6582 .Va pipe-TYPE/SUBTYPE
6585 (normalized to lowercase using character mappings of the ASCII charset)
6586 names a file extension, e.g.,
6588 Handlers registered using this method take precedence.
6590 .Mx Va pop3-keepalive
6591 .It Va pop3-keepalive-USER@HOST , pop3-keepalive-HOST , pop3-keepalive
6592 \*(OP POP3 servers close the connection after a period of inactivity;
6593 the standard requires this to be at least 10 minutes,
6594 but practical experience may vary.
6595 Setting this variable to a numeric value greater than
6599 command to be sent each value seconds if no other operation is performed.
6603 The string printed when a command is accepted.
6604 Prompting may be prevented by either setting this to the null string
6607 The same XSI escape sequences that are understood by the
6609 command may be used within
6612 In addition, the following \*(UA specific additional sequences are
6619 is set, in which case it expands to
6623 is the default value of
6626 which will expand to
6628 if the last command failed and to
6632 which will expand to the name of the currently active
6634 if any, and to the empty string otherwise, and
6636 which will expand to the name of the currently active mailbox.
6637 (Note that the prompt buffer is size-limited, excess is cut off.)
6643 to encapsulate the expansions of the
6647 escape sequences as necessary to correctly display bidirectional text,
6648 this is not true for the final string that makes up
6650 as such, i.e., real BIDI handling is not supported.
6652 When a newer version of the
6654 .Sx "Command line editor"
6655 is used, any escape sequence must itself be encapsulated with another
6656 escape character for usage with the
6658 mechanism: \*(UA configures the control character
6664 If set, \*(UA starts a replying message with the original message
6665 prefixed by the value of the variable
6667 Normally, a heading consisting of
6668 .Dq Fromheaderfield wrote:
6669 is printed before the quotation.
6674 variable, this heading is omitted.
6677 is assigned, the headers selected by the
6678 .Ic ignore Ns / Ns Ic retain
6679 commands are printed above the message body,
6682 acts like an automatic
6688 is assigned, all headers are printed above the message body and all MIME
6689 parts are included, making
6691 act like an automatic
6694 .Va quote-as-attachment .
6698 \*(OP Can be set in addition to
6700 Setting this turns on a more fancy quotation algorithm in that leading
6701 quotation characters are compressed and overlong lines are folded.
6703 can be set to either one or two (space separated) numeric values,
6704 which are interpreted as the maximum (goal) and the minimum line length,
6705 respectively, in a spirit rather equal to the
6707 program, but line-, not paragraph-based.
6708 If not set explicitly the minimum will reflect the goal algorithmically.
6709 The goal can't be smaller than the length of
6711 plus some additional pad.
6712 Necessary adjustments take place silently.
6716 If defined, gives the pathname of the folder used to record all outgoing
6718 If not defined, then outgoing mail is not saved.
6719 When saving to this folder fails the message is not sent,
6720 but instead saved to
6724 .It Va reply_strings
6725 Can be set to a comma-separated list of (case-insensitive according to
6726 ASCII rules) strings which shall be recognized in addition to the
6729 reply message indicators \(en builtin are
6731 which is mandated by RFC 5322, as well as the german
6736 A list of addresses to put into the
6738 field of the message header.
6739 Members of this list are handled as if they were in the
6744 .It Va reply-to-honour
6747 header is honoured when replying to a message via
6751 This is a quadoption; if set without a value it defaults to
6756 When \*(UA initially prints the message headers it determines the number
6757 to print by looking at the speed of the terminal.
6758 The faster the terminal, the more it prints.
6759 This option overrides this calculation and specifies how many message
6760 headers are printed.
6761 This number is also used for scrolling with the
6767 \*(OP A comma-separated list of character set names that can be used in
6768 outgoing internet mail.
6769 The value of the variable
6771 is automatically appended to this list of character-sets.
6772 If no character set conversion capabilities are compiled into \*(UA then
6773 the only supported charset is
6776 .Va sendcharsets-else-ttycharset
6777 and refer to the section
6778 .Sx "Character sets"
6779 for the complete picture of character set conversion in \*(UA.
6783 An address that is put into the
6785 field of outgoing messages, quoting RFC 5322: the mailbox of the agent
6786 responsible for the actual transmission of the message.
6787 This field should normally not be used unless the
6789 field contains more than one address, on which case it is required.
6792 address is handled as if it were in the
6798 To use an alternate mail transport agent (MTA),
6799 set this option to the full pathname of the program to use.
6800 It may be necessary to set
6801 .Va sendmail-progname
6804 The MTA will be passed command line arguments from several possible
6805 sources: from the variable
6806 .Va sendmail-arguments
6807 if set, from the command line if given and the variable
6810 Argument processing of the MTA will be terminated with a
6814 The otherwise occurring implicit usage of the following MTA command line
6815 arguments can be disabled by setting the boolean option
6816 .Va sendmail-no-default-arguments
6817 (which will also disable passing
6821 (for not treating a line with only a dot
6823 character as the end of input),
6831 option is set); in conjunction with the
6833 command line option \*(UA will also pass
6839 .It Va sendmail-arguments
6840 Arguments to pass through to the Mail-Transfer-Agent can be given via
6842 The content of this variable will be split up in a vector of arguments
6843 which will be joined onto other possible MTA options:
6845 .Dl set sendmail-arguments='-t -X \&"/tmp/my log\&"'
6848 .It Va sendmail-no-default-arguments
6849 \*(BY Unless this option is set \*(UA will pass some well known
6850 standard command line options to the defined
6852 program, see there for more.
6855 .It Va sendmail-progname
6856 Many systems use a so-called
6858 environment to ensure compatibility with
6860 This works by inspecting the name that was used to invoke the mail
6862 If this variable is set then the mailwrapper (the program that is
6863 actually executed when calling
6865 will treat its contents as that name.
6871 A string for use with the
6877 A string for use with the
6883 Must correspond to the name of a readable file if set.
6884 The file's content is then appended to each singlepart message
6885 and to the first part of each multipart message.
6886 Be warned that there is no possibility to edit the signature for an
6891 \*(OP Specifies a directory with CA certificates in PEM (Privacy
6892 Enhanced Mail) format for verification of S/MIME signed messages.
6895 .It Va smime-ca-file
6896 \*(OP Specifies a file with CA certificates in PEM format for
6897 verification of S/MIME signed messages.
6900 .It Va smime-cipher-USER@HOST , smime-cipher
6901 \*(OP Specifies the cipher to use when generating S/MIME encrypted
6902 messages (for the specified account).
6903 RFC 5751 mandates a default of
6906 Possible values are (case-insensitive and) in decreasing cipher strength:
6914 (DES EDE3 CBC, 168 bits; default if
6916 isn't available) and
6920 The actually available cipher algorithms depend on the cryptographic
6921 library that \*(UA uses.
6922 \*(OP Support for more cipher algorithms may be available through
6923 dynamic loading via, e.g.,
6924 .Xr EVP_get_cipherbyname 3
6925 (OpenSSL) if \*(UA has been compiled to support this.
6928 .It Va smime-crl-dir
6929 \*(OP Specifies a directory that contains files with CRLs in PEM format
6930 to use when verifying S/MIME messages.
6933 .It Va smime-crl-file
6934 \*(OP Specifies a file that contains a CRL in PEM format to use when
6935 verifying S/MIME messages.
6938 .It Va smime-encrypt-USER@HOST
6939 \*(OP If this variable is set, messages send to the given receiver are
6940 encrypted before sending.
6941 The value of the variable must be set to the name of a file that
6942 contains a certificate in PEM format.
6944 If a message is sent to multiple recipients,
6945 each of them for whom a corresponding variable is set will receive an
6946 individually encrypted message;
6947 other recipients will continue to receive the message in plain text
6949 .Va smime-force-encryption
6951 It is recommended to sign encrypted messages, i.e., to also set the
6955 .Mx Va smime-sign-cert
6956 .It Va smime-sign-cert-USER@HOST , smime-sign-cert
6957 \*(OP Points to a file in PEM format.
6958 For the purpose of signing and decryption this file needs to contain the
6959 user's private key as well as his certificate.
6963 is always derived from the value of
6965 (or, if that contains multiple addresses,
6967 For the purpose of encryption the recipient's public encryption key
6968 (certificate) is expected; the command
6970 can be used to save certificates of signed messages (the section
6971 .Sx "Signed and encrypted messages with S/MIME"
6972 gives some details).
6973 This mode of operation is usually driven by the specialized form.
6975 When decrypting messages the account is derived from the recipient
6980 of the message, which are searched for addresses for which such
6982 \*(UA always uses the first address that matches,
6983 so if the same message is sent to more than one of the user's addresses
6984 using different encryption keys, decryption might fail.
6986 .Mx Va smime-sign-include-certs
6987 .It Va smime-sign-include-certs-USER@HOST , smime-sign-include-certs
6988 \*(OP If used, this is supposed to a consist of a comma-separated list
6989 of files, each of which containing a single certificate in PEM format to
6990 be included in the S/MIME message in addition to the
6993 This is most useful for long certificate chains if it is desired to aid
6994 the receiving party's verification process.
6995 Note that top level certificates may also be included in the chain but
6996 don't play a role for verification.
6998 .Va smime-sign-cert .
6999 Remember that for this
7001 refers to the variable
7003 (or, if that contains multiple addresses,
7006 .Mx Va smime-sign-message-digest
7007 .It Va smime-sign-message-digest-USER@HOST , smime-sign-message-digest
7008 \*(OP Specifies the message digest to use when signing S/MIME messages.
7009 RFC 5751 mandates a default of
7011 Possible values are (case-insensitive and) in decreasing cipher strength:
7019 The actually available message digest algorithms depend on the
7020 cryptographic library that \*(UA uses.
7021 \*(OP Support for more message digest algorithms may be available
7022 through dynamic loading via, e.g.,
7023 .Xr EVP_get_digestbyname 3
7024 (OpenSSL) if \*(UA has been compiled to support this.
7025 Remember that for this
7027 refers to the variable
7029 (or, if that contains multiple addresses,
7034 \*(OP Normally \*(UA invokes the program defined via
7036 to transfer messages, as described in
7037 .Sx "Sending mail" .
7040 variable will instead cause SMTP network connections be made to the
7041 server specified therein in order to directly submit the message.
7042 \*(UA knows about three different
7043 .Dq SMTP protocols :
7045 .Bl -bullet -compact
7047 The plain SMTP protocol (RFC 5321) that normally lives on the
7048 server port 25 and requires setting the
7049 .Va smtp-use-starttls
7050 variable to enter a SSL/TLS encrypted session state.
7051 Assign a value like \*(IN
7052 .Ql [smtp://][user[:password]@]server[:port]
7054 .Ql [smtp://]server[:port] )
7055 to choose this protocol.
7057 Then the so-called SMTPS which is supposed to live on server port 465
7058 and is automatically SSL/TLS secured.
7059 Unfortunately it never became a standardized protocol and may thus not
7060 be supported by your hosts network service database
7061 \(en in fact the port number has already been reassigned to other
7064 SMTPS is nonetheless a commonly offered protocol and thus can be
7065 chosen by assigning a value like \*(IN
7066 .Ql smtps://[user[:password]@]server[:port]
7068 .Ql smtps://server[:port] ) ;
7069 due to the mentioned problems it is usually necessary to explicitly
7074 Finally there is the SUBMISSION protocol (RFC 6409), which usually
7075 lives on server port 587 and is practically identically to the SMTP
7076 protocol from \*(UAs point of view beside that; it requires setting the
7077 .Va smtp-use-starttls
7078 variable to enter a SSL/TLS secured session state.
7079 Assign a value like \*(IN
7080 .Ql submission://[user[:password]@]server[:port]
7082 .Ql submission://server[:port] ) .
7085 For more on credentials etc. please see
7086 .Sx "On URL syntax and credential lookup" .
7087 The SMTP transfer is executed in a child process, which runs
7088 asynchronously unless either the
7093 If it receives a TERM signal, it will abort and save the message to
7097 .It Va smtp-auth-USER@HOST , smtp-auth-HOST , smtp-auth
7098 \*(OP Variable chain that sets the SMTP authentication method.
7105 as well as the \*(OPal methods
7111 method doesn't need any user credentials,
7113 requires a user name and all other methods require a user name and
7121 .Va smtp-auth-password
7123 .Va smtp-auth-user ) .
7128 .Va smtp-auth-USER@HOST :
7129 may override dependend on sender address in the variable
7132 .It Va smtp-auth-password
7133 \*(OP \*(OU Sets the global fallback password for SMTP authentication.
7134 If the authentication method requires a password, but neither
7135 .Va smtp-auth-password
7137 .Va smtp-auth-password-USER@HOST
7139 \*(UA will ask for a password on the user's terminal.
7141 .It Va smtp-auth-password-USER@HOST
7143 .Va smtp-auth-password
7144 for specific values of sender addresses, dependent upon the variable
7147 .It Va smtp-auth-user
7148 \*(OP \*(OU Sets the global fallback user name for SMTP authentication.
7149 If the authentication method requires a user name, but neither
7152 .Va smtp-auth-user-USER@HOST
7154 \*(UA will ask for a user name on the user's terminal.
7156 .It Va smtp-auth-user-USER@HOST
7159 for specific values of sender addresses, dependent upon the variable
7163 .It Va smtp-hostname
7164 \*(IN Normally \*(UA uses the variable
7166 to derive the necessary
7168 information to issue a
7173 can be used to use the
7175 from the SMTP account
7182 from the content of this variable (or, if that is the empty string,
7184 or the local hostname as a last resort).
7185 This often allows using an address that is itself valid but hosted by
7186 a provider other than which (in
7188 is about to send the message.
7189 Setting this variable also influences the generated
7194 .It Va spam-interface
7195 \*(OP In order to use any of the spam-related commands (like, e.g.,
7197 the desired spam interface must be defined by setting this variable.
7198 Please refer to the manual section
7200 for the complete picture of spam handling in \*(UA.
7201 All or none of the following interfaces may be available:
7203 .Bl -tag -width ".It Ql _ilte_"
7209 .Pf ( Lk http://spamassassin.apache.org SpamAssassin )
7211 Different to the generic filter interface \*(UA will automatically add
7212 the correct arguments for a given command and has the necessary
7213 knowledge to parse the program's output.
7216 will have been compiled into the \*(UA binary if
7221 Shall it be necessary to define a specific connection type (rather than
7222 using a configuration file for that), the variable
7224 can be used as in, e.g.,
7225 .Ql -d server.example.com -p 783 .
7226 It is also possible to specify a per-user configuration via
7228 Note that this interface doesn't inspect the
7230 flag of a message for the command
7234 \*(UA will directly communicate with the
7240 stream socket as specified in
7242 It is possible to specify a per-user configuration via
7246 generic spam filter support via freely configurable hooks.
7247 This interface is ment for programs like
7251 and requires according behaviour in respect to the hooks' exit
7252 status for at least the command
7255 meaning a message is spam,
7259 for unsure and any other return value indicating a hard error);
7260 since the hooks can include shell code snippets diverting behaviour
7261 can be intercepted as necessary.
7263 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
7266 .Va spamfilter-spam ;
7269 contains examples for some programs.
7270 The process environment of the hooks will have the variables
7271 .Ev NAIL_TMPDIR , TMPDIR
7273 .Ev NAIL_FILENAME_GENERATED
7275 Note that spam score support for
7277 isn't supported unless the \*(OPtional regular expression support is
7279 .Va spamfilter-rate-scanscore
7286 \*(OP Messages that exceed this size won't be passed through to the
7288 .Va spam-interface .
7289 The default is 420000 bytes.
7292 .It Va spamc-command
7293 \*(OP The path to the
7297 .Va spam-interface .
7298 Note that the path is not expanded, but used
7300 A fallback path will have been compiled into the \*(UA binary if the
7301 executable had been found during compilation.
7304 .It Va spamc-arguments
7305 \*(OP Even though \*(UA deals with most arguments for the
7308 automatically, it may at least sometimes be desirable to specifiy
7309 connection-related ones via this variable, e.g.,
7310 .Ql -d server.example.com -p 783 .
7314 \*(OP Specify a username for per-user configuration files for the
7316 .Va spam-interface .
7317 If this is set to the empty string then \*(UA will use the name of the
7323 \*(OP Specify the path of the
7325 domain socket on which
7327 listens for connections for the
7329 .Va spam-interface .
7330 Note that the path is not expanded, but used
7335 \*(OP Specify a username for per-user configuration files for the
7337 .Va spam-interface .
7338 If this is set to the empty string then \*(UA will use the name of the
7347 .It Va spamfilter-ham , spamfilter-noham , \
7348 spamfilter-nospam , spamfilter-rate , spamfilter-spam
7349 \*(OP Command and argument hooks for the
7351 .Va spam-interface .
7354 contains examples for some programs.
7357 .It Va spamfilter-rate-scanscore
7358 \*(OP Because of the generic nature of the
7361 spam scores are not supported for it by default, but if the \*(OPtional
7362 regular expression support is available then setting this variable can
7363 be used to overcome this restriction.
7364 It is interpreted as follows: first a number (digits) is parsed that
7365 must be followed by a semicolon
7367 and a regular expression.
7368 Then the latter is used to parse the first output line of the
7370 hook, and, in case the evaluation is successful, the group that has been
7371 specified via the number is interpreted as a floating point scan score.
7375 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
7376 Enhanced Mail) for verification of of SSL/TLS server certificates.
7378 .Xr SSL_CTX_load_verify_locations 3
7379 for more information.
7383 \*(OP Specifies a file with CA certificates in PEM format for
7384 verification of SSL/TLS server certificates.
7386 .Xr SSL_CTX_load_verify_locations 3
7387 for more information.
7390 .It Va ssl-cert-USER@HOST , ssl-cert-HOST , ssl-cert
7391 \*(OP Variable chain that sets the file name for a SSL/TLS client
7392 certificate required by some servers.
7393 This is a direct interface to the
7397 function of the OpenSSL library, if available.
7399 .Mx Va ssl-cipher-list
7400 .It Va ssl-cipher-list-USER@HOST , ssl-cipher-list-HOST , ssl-cipher-list
7401 \*(OP Specifies a list of ciphers for SSL/TLS connections.
7402 This is a direct interface to the
7406 function of the OpenSSL library, if available; see
7408 for more information.
7409 By default \*(UA doesn't set a list of ciphers, which in effect will use a
7411 specific cipher (protocol standards ship with a list of acceptable
7412 ciphers), possibly cramped to what the actually used SSL/TLS library
7413 supports \(en the manual section
7414 .Sx "An example configuration"
7415 also contains a SSL/TLS use case.
7418 .It Va ssl-config-file
7419 \*(OP If this variable is set \*(UA will call
7420 .Xr CONF_modules_load_file 3
7421 to allow OpenSSL to be configured according to the host system wide
7423 If a non-empty value is given then this will be used to specify the
7424 configuration file to be used instead of the global OpenSSL default;
7425 note that in this case it is an error if the file cannot be loaded.
7426 The application name will always be passed as
7431 \*(OP Specifies a file that contains a CRL in PEM format to use when
7432 verifying SSL/TLS server certificates.
7436 \*(OP Specifies a directory that contains files with CRLs in PEM format
7437 to use when verifying SSL/TLS server certificates.
7440 .It Va ssl-key-USER@HOST , ssl-key-HOST , ssl-key
7441 \*(OP Variable chain that sets the file name for the private key of
7442 a SSL/TLS client certificate.
7443 If unset, the name of the certificate file is used.
7444 The file is expected to be in PEM format.
7445 This is a direct interface to the
7449 function of the OpenSSL library, if available.
7452 .It Va ssl-method-USER@HOST , ssl-method-HOST , ssl-method
7454 \*(OB Please use the newer and more flexible
7456 instead: if both values are set,
7458 will take precedence!
7459 Can be set to the following values, the actually used
7461 specification to which it is mapped is shown in parenthesis:
7463 .Pf ( Ql -ALL, TLSv1.2 ) ,
7465 .Pf ( Ql -ALL, TLSv1.1 ) ,
7467 .Pf ( Ql -ALL, TLSv1 )
7470 .Pf ( Ql -ALL, SSLv3 ) ;
7475 and thus includes the SSLv3 protocol.
7476 Note that SSLv2 is no longer supported at all.
7479 .It Va ssl-protocol-USER@HOST , ssl-protocol-HOST , ssl-protocol
7480 \*(OP Specify the used SSL/TLS protocol.
7481 This is a direct interface to the
7485 function of the OpenSSL library, if available;
7486 otherwise an \*(UA internal parser is used which understands the
7487 following subset of (case-insensitive) command strings:
7493 as well as the special value
7495 Multiple specifications may be given via a comma-separated list which
7496 ignores any whitespace.
7499 plus prefix will enable a protocol, a
7501 minus prefix will disable it, so that
7503 will enable only the TLSv1.2 protocol.
7505 It depends upon the used TLS/SSL library which protocols are actually
7506 supported and which protocols are used if
7508 is not set, but note that SSLv2 is no longer supported at all and
7510 Especially for older protocols explicitly securing
7512 may be worthwile, see
7513 .Sx "An example configuration" .
7517 \*(OP Gives the pathname to an entropy daemon socket, see
7519 Not all SSL/TLS libraries support this.
7522 .It Va ssl-rand-file
7523 \*(OP Gives the pathname to a file with entropy data, see
7524 .Xr RAND_load_file 3 .
7525 If the file is a regular file writable by the invoking user,
7526 new data is written to it after it has been loaded.
7529 .It Va ssl-verify-USER@HOST , ssl-verify-HOST , ssl-verify
7530 \*(OP Variable chain that sets the action to be performed if an error
7531 occurs during SSL/TLS server certificate validation.
7532 Valid (case-insensitive) values are
7534 (fail and close connection immediately),
7536 (ask whether to continue on standard input),
7538 (print a warning and continue),
7540 (do not perform validation).
7546 If only set without an assigned value, then this option inhibits the
7551 header fields that include obvious references to \*(UA.
7552 There are two pitfalls associated with this:
7553 First, the message id of outgoing messages is not known anymore.
7554 Second, an expert may still use the remaining information in the header
7555 to track down the originating mail user agent.
7560 suppression doesn't occur.
7564 If defined, gives the number of lines of a message to be printed out
7565 with the top command; normally, the first five lines are printed.
7569 The character set of the terminal \*(UA operates on,
7570 and the one and only supported character set that \*(UA can use if no
7571 character set conversion capabilities have been compiled into it,
7572 in which case it defaults to ISO-8859-1 unless it can deduce a value
7576 Refer to the section
7577 .Sx "Character sets"
7578 for the complete picture about character sets.
7581 .It Va user-HOST , user
7582 \*(IN Variable chain that sets a global fallback user name, which is
7583 used in case none has been given in the protocol and account-specific
7585 This variable defaults to the value of
7592 .It Va version , version-major , version-minor , version-update
7593 \*(RO \*(UA version information: the first variable contains a string
7594 containing the complete version identification \(en this is identical to
7595 the output of the command
7597 The latter three contain only digits: the major, minor and update
7601 .\" }}} (Variable options)
7604 .\" .Sh ENVIRONMENT {{{
7608 .Dq environment variable
7609 should be considered an indication that the following variables are
7610 either standardized as being vivid parts of process environments, or
7611 are commonly found in there.
7612 Unless otherwise explicitly noted they integrate into the normal
7613 variable handling, as documented above, from \*(UAs point of view.
7615 .Bl -tag -width ".It Ev _AILR_"
7618 The user's preferred width in column positions for the terminal screen
7620 Queried and used once on program startup.
7624 The name of the file to use for saving aborted messages if
7626 is set; this defaults to
7634 Pathname of the text editor to use in the
7638 .Sx "TILDE ESCAPES" .
7639 A default editor is used if this value is not defined.
7643 The user's home directory.
7644 This variable is only used when it resides in the process environment.
7647 to update the value at runtime.
7654 .It Ev LANG , LC_ALL , LC_COLLATE , LC_CTYPE , LC_MESSAGES
7658 .Sx "Character sets" .
7662 The user's preferred number of lines on a page or the vertical screen
7663 or window size in lines.
7664 Queried and used once on program startup.
7668 Pathname of the directory lister to use in the
7670 command when operating on local mailboxes.
7673 (path search through
7678 The name of the user's mbox file.
7679 Supports a logical subset of the special conventions that are
7685 The fallback default is
7693 Is used as the user's primary system mailbox, unless
7697 This is assumed to be an absolute pathname.
7701 Is used as a startup file instead of
7704 When \*(UA scripts are invoked on behalf of other users,
7705 this variable should be set to
7707 to avoid side-effects from reading their configuration files.
7708 This variable is only used when it resides in the process environment.
7711 .It Ev NAIL_NO_SYSTEM_RC
7712 If this variable is set then reading of
7714 at startup is inhibited, i.e., the same effect is achieved as if \*(UA
7715 had been started up with the option
7717 This variable is only used when it resides in the process environment.
7721 \*(IN \*(OP This variable overrides the default location of the user's
7727 Pathname of the program to use in the more command or when the
7730 The default paginator is
7732 (path search through
7737 A list of directories that is searched by the shell when looking for
7738 commands (as such only recognized in the process environment).
7742 The shell to use for the commands
7748 and when starting subprocesses.
7749 A default shell is used if this option is not defined.
7753 Changes the letters printed in the first column of a header summary.
7757 \*(OP The terminal type for which output is to be prepared.
7761 Used as directory for temporary files instead of
7764 This variable is only used when it resides in the process environment.
7767 to update the value at runtime.
7771 Force identification as the given user, i.e., identical to the
7773 command line option.
7774 This variable is only used when it resides in the process environment.
7777 to update the value at runtime, but note that doing so won't trigger any
7778 of those validation checks that were performed on program startup (again).
7782 Pathname of the text editor to use in the
7786 .Sx "TILDE ESCAPES" .
7794 .Bl -tag -width ".It Pa _etc/mime.type_"
7796 File giving initial commands.
7799 System wide initialization file.
7802 .It Pa ~/.mime.types
7803 Personal MIME types, see
7804 .Sx "The mime.types files" .
7807 .It Pa /etc/mime.types
7808 System wide MIME types, see
7809 .Sx "The mime.types files" .
7813 \*(IN \*(OP The default location of the users
7815 file \(en the section
7816 .Sx "The .netrc file"
7817 documents the file format.
7820 .\" .Ss "The mime.types files" {{{
7821 .Ss "The mime.types files"
7823 When sending messages \*(UA tries to determine the content type of all
7825 When displaying message content or attachments \*(UA uses the content
7826 type to decide whether it can directly display data or whether it needs to
7827 deal with content handlers, as can be defined via
7828 .Va pipe-TYPE/SUBTYPE
7830 .Va pipe-EXTENSION )
7831 variables, to do so.
7834 It learns about MIME types and how to treat them by reading
7836 files, the loading of which can be controlled by setting the variable
7837 .Va mimetypes-load-control .
7840 can also be used to deal with MIME types.)
7842 files have the following syntax:
7845 .Dl type/subtype extension [extension ...]
7850 are strings describing the file contents, and one or multiple
7852 s, separated by whitespace, name the part of a filename starting after
7853 the last dot (of interest).
7854 Comments may be introduced anywhere on a line with a number sign
7856 causing the remaining line to be discarded.
7858 \*(UA also supports an extended, non-portable syntax in specially
7859 crafted files, which can be loaded via the alternative value syntax of
7860 .Va mimetypes-load-control
7861 and prepends an optional
7865 .Dl [type-marker ]type/subtype extension [extension ...]
7868 The following type markers are supported:
7871 .Bl -tag -compact -offset indent -width ".It Ar _n_u"
7873 Treat message parts with this content as plain text.
7878 Treat message parts with this content as HTML tagsoup.
7879 If the \*(OPal HTML-tagsoup-to-text converter is not available treat
7880 the content as plain text instead.
7884 but instead of falling back to plain text require an explicit content
7885 handler to be defined.
7890 for sending messages:
7891 .Va mime-allow-text-controls .
7892 For reading etc. messages:
7893 .Sx "Viewing HTML mail and MIME attachments" ,
7894 .Va mime-counter-evidence ,
7895 .Va pipe-TYPE/SUBTYPE ,
7896 .Va pipe-EXTENSION .
7899 .\" .Ss "The .netrc file" {{{
7900 .Ss "The .netrc file"
7904 file contains user credentials for machine accounts.
7905 The default location in the user's
7907 directory may be overridden by the
7909 environment variable.
7910 The file consists of space, tabulator or newline separated tokens.
7911 \*(UA implements a parser that supports a superset of the original BSD
7912 syntax, but users should nonetheless be aware of portability glitches
7913 of that file format, shall their
7915 be usable across multiple programs and platforms:
7918 .Bl -bullet -compact
7920 BSD doesn't support single, but only double quotation marks, e.g.,
7921 .Ql password="pass with spaces" .
7923 BSD (only?) supports escaping of single characters via a backslash
7924 (e.g., a space can be escaped via
7926 in- as well as outside of a quoted string.
7928 BSD doesn't require the final quotation mark of the final user input token.
7930 At least Hewlett-Packard seems to support a format which also allows
7931 tokens to be separated with commas \(en this format is not supported!
7933 Whereas other programs may require that the
7935 file is accessible by only the user if it contains a
7941 \*(UA will always require these strict permissions.
7945 Of the following list of supported tokens \*(UA only uses (and caches)
7951 .Bl -tag -width password
7952 .It Cd machine Ar name
7953 The hostname of the entries' machine, lowercase-normalized by \*(UA
7955 Any further file content, until either end-of-file or the occurrence
7960 first-class token is bound (only related) to the machine
7963 As an extension that shouldn't be the cause of any worries
7964 \*(UA supports a single wildcard prefix for
7966 .Bd -literal -offset indent
7967 machine *.example.com login USER password PASS
7968 machine pop3.example.com login USER password PASS
7969 machine smtp.example.com login USER password PASS
7975 .Ql pop3.example.com ,
7979 .Ql local.smtp.example.com .
7980 Note that in the example neither
7981 .Ql pop3.example.com
7983 .Ql smtp.example.com
7984 will be matched by the wildcard, since the exact matches take
7985 precedence (it is however faster to specify it the other way around).
7990 except that it is a fallback entry that is used shall none of the
7991 specified machines match; only one default token may be specified,
7992 and it must be the last first-class token.
7994 .It Cd login Ar name
7995 The user name on the remote machine.
7997 .It Cd password Ar string
7998 The user's password on the remote machine.
8000 .It Cd account Ar string
8001 Supply an additional account password.
8002 This is merely for FTP purposes.
8004 .It Cd macdef Ar name
8006 A macro is defined with the specified
8008 it is formed from all lines beginning with the next line and continuing
8009 until a blank line is (consecutive newline characters are) encountered.
8012 entries cannot be utilized by multiple machines, too, but must be
8013 defined following the
8015 they are intended to be used with.)
8018 exists, it is automatically run as the last step of the login process.
8019 This is merely for FTP purposes.
8026 .\" .Sh EXAMPLES {{{
8029 .\" .Ss "An example configuration" {{{
8030 .Ss "An example configuration"
8032 .Bd -literal -offset indent
8033 # This example assumes v15.0 compatibility mode
8036 # Where are the up-to-date SSL certificates?
8037 #set ssl-ca-dir=/etc/ssl/certs
8038 set ssl-ca-file=/etc/ssl/certs/ca-certificates.crt
8040 # (Since we manage up-to-date ones explicitly, don't use any,
8041 # possibly outdated, default certificates shipped with OpenSSL
8042 set ssl-no-default-ca
8044 # Don't use protocols olders than TLS v1.2.
8045 # Change this only when the remote server doesn't support it:
8046 # maybe use ssl-protocol-HOST (or -USER@HOST) syntax to define
8047 # such explicit exceptions, then
8048 set ssl-protocol="-ALL,+TLSv1.2"
8050 # Explicitly define the list of ciphers, which may improve security,
8051 # especially with protocols older than TLS v1.2. See ciphers(1).
8052 # Hint: it is important to include "@STRENGTH": only with it the
8053 # final list will be sorted by algorithm strength.
8054 # This is an example: in reality it is possibly best to only use
8055 # ssl-cipher-list-HOST (or -USER@HOST), as necessary, again..
8056 set ssl-cipher-list="ALL:!aNULL:!MEDIUM:!LOW:\e
8057 !MD5:!RC4:!EXPORT:@STRENGTH"
8059 # Request strict transport security checks!
8060 set ssl-verify=strict
8062 # Essential setting: select allowed character sets
8063 set sendcharsets=utf-8,iso-8859-1
8065 # A very kind option: when replying to a message, first try to
8066 # use the same encoding that the original poster used herself!
8067 set reply-in-same-charset
8069 # When replying to or forwarding a message the comment and name
8070 # parts of email addresses are removed unless this variable is set
8073 # When sending messages, wait until the Mail-Transfer-Agent finishs.
8074 # Only like this you'll be able to see errors reported through the
8075 # exit status of the MTA (including the builtin SMTP one)!
8078 # Only use builtin MIME types, no mime.types(5) files
8079 set mimetypes-load-control
8081 # Default directory where we act in (relative to $HOME)
8082 set folder=mail MBOX=+mbox.mbox record=+sent.mbox \e
8085 # Make "file mymbox" and "file myrec" go to..
8086 shortcut mymbox %:+mbox.mbox myrec +sent.mbox
8088 # Not really optional, e.g., for S/MIME
8089 set from="Your Name <youremail@domain>"
8091 # It may be necessary to set hostname and/or smtp-hostname
8092 # if the "SERVER" of smtp and "domain" of from don't match.
8093 # The `urlcodec' command can be used to encode USER and PASS
8094 set smtp=(smtp[s]/submission)://[USER[:PASS]@]SERVER[:PORT] \e
8095 smtp-auth=login/plain... \e
8098 # Never refuse to start into interactive mode, and more
8100 colour-pager crt= followup-to followup-to-honour=ask-yes \e
8101 history-gabby mime-counter-evidence=6 \e
8102 prompt="\e033[31m?\e?[\e$ \e@]\e& \e033[0m" \e
8103 NAIL_HISTFILE=+.s-nailhist NAIL_HISTSIZE=-1 \e
8104 reply-to-honour=ask-yes
8106 # When `p'rinting messages, show only these headers
8107 # (use `P'rint for all headers and `S'how for raw message)
8108 retain date from to cc subject
8110 # Some mailing lists
8111 mlist @xyz-editor.xyz$ @xyzf.xyz$
8112 mlsubscribe ^xfans@xfans.xyz$
8114 # A real life example of a very huge free mail provider
8117 set from="Your Name <youremail@domain>"
8118 # (The plain smtp:// proto is optional)
8119 set smtp=USER:PASS@smtp.gmXil.com smtp-use-starttls
8122 # Here is a pretty large one which does not allow sending mails
8123 # if there is a domain name mismatch on the SMTP protocol level,
8124 # which would bite us if the value of from does not match, e.g.,
8125 # for people who have a sXXXXeforge project and want to speak
8126 # with the mailing list under their project account (in from),
8127 # still sending the message through their normal mail provider
8130 set from="Your Name <youremail@domain>"
8131 set smtp=smtps://USER:PASS@smtp.yaXXex.ru:465 \e
8132 hostname=yaXXex.com smtp-hostname=
8135 # Create some new commands so that, e.g., `ls /tmp' will..
8146 ghost llS !ls -aFlrS
8149 # We don't support gpg(1) directly yet. But simple --clearsign'd
8150 # message parts can be dealt with as follows:
8153 set pipe-text/plain="set -C;\e
8154 : > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" \e
8155 trap \e"rm -f \e\e\e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e\e\e"\e" \e
8156 EXIT INT QUIT PIPE TERM;\e
8158 cat > \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e";\e
8159 < \e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" awk \e
8160 -v TMPFILE=\e"${TMPDIR}/${NAIL_FILENAME_GENERATED}\e" '\e
8162 /^-----BEGIN PGP SIGNED MESSAGE-----/,/^$/ {\e
8165 print \e"--- GPG --verify ---\e";\e
8166 system(\e"gpg --verify \e" TMPFILE \e" 2>&1\e");\e
8167 print \e"--- GPG --verify ---\e";\e
8171 /^-----BEGIN PGP SIGNATURE-----/,\e
8172 /^-----END PGP SIGNATURE-----/ {\e
8182 !printf 'Key IDs to gpg --recv-keys: ';\e
8184 gpg --recv-keys ${keyids};
8190 When storing passwords in
8192 appropriate permissions should be set on this file with
8193 .Ql $ chmod 0600 \*(ur .
8196 is available user credentials can be stored in the central
8198 file instead; e.g., here is a different version of the example account
8199 that sets up SMTP and POP3:
8201 .Bd -literal -offset indent
8204 set from="Your Name <youremail@domain>"
8206 #set agent-shell-lookup="gpg -d .pass.gpg"
8208 set smtp=smtps://smtp.yXXXXx.ru:465 \e
8209 smtp-hostname= hostname=yXXXXx.com
8210 set pop3-keepalive=240 pop3-no-apop-pop.yXXXXx.ru
8211 ghost xp fi pop3s://pop.yXXXXx.ru
8220 .Bd -literal -offset indent
8221 machine *.yXXXXx.ru login USER password PASS
8226 .Va agent-shell-lookup
8227 is available things could be diversified further by using encrypted
8228 password storage: for this, don't specify
8232 file and instead uncomment the line that defines agent lookup in the
8235 above, then create the encrypted password storage file
8238 .Bd -literal -offset indent
8241 $ eval `gpg-agent --daemon \e
8242 --pinentry-program=/usr/bin/pinentry-curses \e
8243 --max-cache-ttl 99999 --default-cache-ttl 99999`
8247 This configuration should now work just fine (use the
8249 command line option for a(n almost) dry-run):
8252 .Dl $ echo text | \*(ua -vv -AXandeX -s Subject some@where
8255 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
8256 .Ss "Signed and encrypted messages with S/MIME"
8258 \*(OP S/MIME provides two central mechanisms:
8259 message signing and message encryption.
8260 A signed message contains some data in addition to the regular text.
8261 The data can be used to verify that the message was sent using a valid
8262 certificate, that the sender's address in the message header matches
8263 that in the certificate, and that the message text has not been altered.
8264 Signing a message does not change its regular text;
8265 it can be read regardless of whether the recipient's software is able to
8269 It is thus usually possible to sign all outgoing messages if so desired.
8270 Encryption, in contrast, makes the message text invisible for all people
8271 except those who have access to the secret decryption key.
8272 To encrypt a message, the specific recipient's public encryption key
8274 It is therefore not possible to send encrypted mail to people unless their
8275 key has been retrieved from either previous communication or public key
8277 A message should always be signed before it is encrypted.
8278 Otherwise, it is still possible that the encrypted message text is
8282 A central concept to S/MIME is that of the certification authority (CA).
8283 A CA is a trusted institution that issues certificates.
8284 For each of these certificates it can be verified that it really
8285 originates from the CA, provided that the CA's own certificate is
8287 A set of CA certificates is usually delivered with OpenSSL and installed
8289 If you trust the source of your OpenSSL software installation,
8290 this offers reasonable security for S/MIME on the Internet.
8292 .Va ssl-no-default-ca
8296 .Va smime-ca-dir . )
8297 In general, a certificate cannot be more secure than the method its CA
8298 certificate has been retrieved with, though.
8299 Thus if you download a CA certificate from the Internet,
8300 you can only trust the messages you verify using that certificate as
8301 much as you trust the download process.
8304 The first thing you need for participating in S/MIME message exchange is
8305 your personal certificate, including a private key.
8306 The certificate contains public information, in particular your name and
8307 your email address(es), and the public key that is used by others to
8308 encrypt messages for you,
8309 and to verify signed messages they supposedly received from you.
8310 The certificate is included in each signed message you send.
8311 The private key must be kept secret.
8312 It is used to decrypt messages that were previously encrypted with your
8313 public key, and to sign messages.
8316 For personal use it is recommended that you get a S/MIME certificate
8317 from one of the major CAs on the Internet using your WWW browser.
8318 Many CAs offer such certificates for free.
8320 .Lk https://www.CAcert.org
8321 which issues client and server certificates to members of their
8322 community for free; their root certificate
8323 .Pf ( Lk https://\:www.cacert.org/\:certs/\:root.crt )
8324 is often not in the default set of trusted CA root certificates, though,
8325 which means you will have to download their root certificate separately
8326 and ensure it is part of our S/MIME certificate validation chain by
8329 or as a vivid member of the
8331 But let's take a step-by-step tour on how to setup S/MIME with
8332 a certificate from CAcert.org despite this situation!
8335 First of all you will have to become a member of the CAcert.org
8336 community, simply by registrating yourself via the web interface.
8337 Once you are, create and verify all email addresses you want to be able
8338 to create signed and encrypted messages for/with using the corresponding
8339 entries of the web interface.
8340 Now ready to create S/MIME certificates, so let's create a new
8341 .Dq client certificate ,
8342 ensure to include all email addresses that should be covered by the
8343 certificate in the following web form, and also to use your name as the
8347 Create a private key and a certificate request on your local computer
8348 (please see the manual pages of the used commands for more in-depth
8349 knowledge on what the used arguments etc. do):
8352 .Dl openssl req -nodes -newkey rsa:4096 -keyout key.pem -out creq.pem
8355 Afterwards copy-and-paste the content of
8357 into the certificate-request (CSR) field of the web form on the
8358 CAcert.org website (you may need to unfold some
8359 .Dq advanced options
8360 to see the corresponding text field).
8361 This last step will ensure that your private key (which never left your
8362 box) and the certificate belong together (through the public key that
8363 will find its way into the certificate via the certificate-request).
8364 You are now ready and can create your CAcert certified certificate.
8365 Download and store or copy-and-paste it as
8370 In order to use your new S/MIME setup you will have to create
8371 a combined private key/public key (certificate) file:
8374 .Dl cat key.pem pub.crt > ME@HERE.com.paired
8377 This is the file \*(UA will work with.
8378 If you have created your private key with a passphrase then \*(UA will
8379 ask you for it whenever a message is signed or decrypted.
8380 Set the following variables to henceforth use S/MIME (setting
8382 is of interest for verification only):
8384 .Bd -literal -offset indent
8385 set smime-ca-file=ALL-TRUSTED-ROOT-CERTS-HERE \e
8386 smime-sign-cert=ME@HERE.com.paired \e
8387 smime-sign-message-digest=SHA256 \e
8392 From each signed message you send, the recipient can fetch your
8393 certificate and use it to send encrypted mail back to you.
8394 Accordingly if somebody sends you a signed message, you can do the same,
8397 command to check the validity of the certificate.
8400 Options of interest for S/MIME signing:
8404 .Va smime-crl-file ,
8405 .Va smime-no-default-ca ,
8407 .Va smime-sign-cert ,
8408 .Va smime-sign-include-certs
8410 .Va smime-sign-message-digest .
8413 After it has been verified save the certificate via
8415 and tell \*(UA that it should use it for encryption for further
8416 communication with that somebody:
8418 .Bd -literal -offset indent
8420 set smime-encrypt-USER@HOST=FILENAME \e
8421 smime-cipher-USER@HOST=AES256
8425 Additional options of interest for S/MIME en- and decryption:
8428 .Va smime-encrypt-USER@HOST .
8431 You should carefully consider if you prefer to store encrypted messages
8433 If you do, anybody who has access to your mail folders can read them,
8434 but if you do not, you might be unable to read them yourself later if
8435 you happen to lose your private key.
8438 command saves messages in decrypted form, while the
8442 commands leave them encrypted.
8445 Note that neither S/MIME signing nor encryption applies to message
8446 subjects or other header fields yet.
8447 Thus they may not contain sensitive information for encrypted messages,
8448 and cannot be trusted even if the message content has been verified.
8449 When sending signed messages,
8450 it is recommended to repeat any important header information in the
8454 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
8455 .Ss "Using CRLs with S/MIME or SSL/TLS"
8457 \*(OP Certification authorities (CAs) issue certificate revocation
8458 lists (CRLs) on a regular basis.
8459 These lists contain the serial numbers of certificates that have been
8460 declared invalid after they have been issued.
8461 Such usually happens because the private key for the certificate has
8463 because the owner of the certificate has left the organization that is
8464 mentioned in the certificate, etc.
8465 To seriously use S/MIME or SSL/TLS verification,
8466 an up-to-date CRL is required for each trusted CA.
8467 There is otherwise no method to distinguish between valid and
8468 invalidated certificates.
8469 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
8470 the Internet, so you have to retrieve them by some external mechanism.
8473 \*(UA accepts CRLs in PEM format only;
8474 CRLs in DER format must be converted, like, e.\|g.:
8477 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
8480 To tell \*(UA about the CRLs, a directory that contains all CRL files
8481 (and no other files) must be created.
8486 variables, respectively, must then be set to point to that directory.
8487 After that, \*(UA requires a CRL to be present for each CA that is used
8488 to verify a certificate.
8491 .\" .Ss "Handling spam" {{{
8494 \*(OP \*(UA can make use of several spam interfaces for the purpose of
8495 identification of, and, in general, dealing with spam messages.
8496 A precondition of most commands in order to function is that the
8498 variable is set to one of the supported interfaces.
8499 Once messages have been identified as spam their (volatile)
8501 state can be prompted: the
8505 message specifications will address respective messages and their
8507 entries will be used when displaying the
8509 in the header display.
8514 rates the given messages and sets their
8517 If the spam interface offers spam scores those can also be displayed in
8518 the header display by including the
8528 will interact with the Bayesian filter of the chosen interface and learn
8529 the given messages as
8533 respectively; the last command can be used to cause
8535 of messages; it adheres to their current
8537 state and thus reverts previous teachings.
8542 will simply set and clear, respectively, the mentioned volatile
8544 message flag, without any interface interaction.
8551 .Va spam-interface Ns s
8555 require a running instance of the
8557 server in order to function, started with the option
8559 shall Bayesian filter learning be possible.
8561 only works via a local path-based
8563 socket, but otherwise the following will be equivalently fine:
8565 .Bd -literal -offset indent
8566 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
8567 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \e
8568 --daemonize [--local] [--allow-tell]
8572 Thereafter \*(UA can make use of these interfaces:
8574 .Bd -literal -offset indent
8575 $ \*(ua -Sspam-interface=spamd -Sspam-maxsize=500000 \e
8576 -Sspamd-socket=/tmp/.spamsock -Sspamd-user=
8578 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
8579 -Sspamc-command=/usr/local/bin/spamc \e
8580 -Sspamc-arguments="-U /tmp/.spamsock" -Sspamc-user=
8582 $ \*(ua -Sspam-interface=spamc -Sspam-maxsize=500000 \e
8583 -Sspamc-command=/usr/local/bin/spamc \e
8584 -Sspamc-arguments="-d localhost -p 2142" -Sspamc-user=
8588 Using the generic filter approach allows usage of programs like
8592 Here is an example for the former, requiring it to be accessible via
8595 .Bd -literal -offset indent
8596 $ \*(ua -Sspam-interface=filter -Sspam-maxsize=500000 \e
8597 -Sspamfilter-ham="bogofilter -n" \e
8598 -Sspamfilter-noham="bogofilter -N" \e
8599 -Sspamfilter-nospam="bogofilter -S" \e
8600 -Sspamfilter-rate="bogofilter -TTu 2>/dev/null" \e
8601 -Sspamfilter-spam="bogofilter -s" \e
8602 -Sspamfilter-rate-scanscore="1;^(.+)$"
8606 Because messages must exist on local storage in order to be scored (or
8607 used for Bayesian filter training), it is possibly a good idea to
8608 perform the local spam check last:
8610 .Bd -literal -offset indent
8611 define spamdelhook {
8613 spamset (header x-dcc-brand-metrics "bulk")
8614 # Server-side spamassassin(1)
8615 spamset (header x-spam-flag "YES")
8616 del :s # TODO we HAVE to be able to do `spamrate :u ! :sS'
8622 set folder-hook-FOLDER=spamdelhook
8626 See also the documentation for the variables
8627 .Va spam-interface , spam-maxsize ,
8628 .Va spamc-command , spamc-arguments , spamc-user ,
8629 .Va spamd-socket , spamd-user ,
8630 .Va spamfilter-ham , spamfilter-noham , spamfilter-nospam , \
8633 .Va spamfilter-rate-scanscore .
8641 .\" .Ss "\*(UA shortly hangs on startup" {{{
8642 .Ss "\*(UA shortly hangs on startup"
8644 This can have two reasons, one is the necessity to wait for a file lock
8645 and can't be helped, the other being that \*(UA calls the function
8647 in order to query the nodename of the box (sometimes the real one is
8648 needed instead of the one represented by the internal variable
8650 You may have varying success by ensuring that the real hostname and
8654 or, more generally, that the name service is properly setup \(en
8657 return what you'd expect?
8660 .\" .Ss "I can't login to Google mail a.k.a. GMail" {{{
8661 .Ss "I can't login to Google mail a.k.a. GMail"
8663 Since 2014 some free service providers classify programs as
8665 unless they use a special authentification method (OAuth 2.0) which
8666 wasn't standardized for non-HTTP protocol authentication token query
8667 until August 2015 (RFC 7628).
8670 Different to Kerberos / GSSAPI, which is developed since the mid of the
8671 1980s, where a user can easily create a local authentication ticket for
8672 her- and himself with the locally installed
8674 program, that protocol has no such local part but instead requires
8675 a world-wide-web query to create or fetch a token; since there is no
8676 local cache this query has to be performed whenever \*(UA is invoked
8677 from the command line (in interactive sessions situation may differ).
8680 \*(UA doesn't support OAuth.
8681 Because of this it is necessary to declare \*(UA a
8683 (on the providers account web page) in order to read and send mail.
8684 However, it also seems possible to take the following steps instead:
8689 give the provider the number of a mobile phone,
8692 .Dq 2-Step Verification ,
8694 create an application specific password (16 characters), and
8696 use that special password instead of your real Google account password in
8697 S-nail (for more on that see the section
8698 .Sx "On URL syntax and credential lookup" ) .
8704 .\" .Sh "SEE ALSO" {{{
8722 .Xr spamassassin 1 ,
8749 command appeared in Version 1 AT&T Unix.
8750 Berkeley Mail was written in 1978 by Kurt Shoens.
8751 This man page is derived from from
8752 .Dq The Mail Reference Manual
8753 originally written by Kurt Shoens.
8755 enhancements are maintained and documented by Gunnar
8758 is maintained and documented by Steffen (Daode) Nurpmeso.
8761 Portions of this text are reprinted and reproduced in electronic form
8762 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
8763 \(en Operating System Interface (POSIX), The Open Group Base
8764 Specifications Issue 6, Copyright \(co 2001-2003 by the Institute of
8765 Electrical and Electronics Engineers, Inc and The Open Group.
8766 In the event of any discrepancy between this version and the original
8767 IEEE and The Open Group Standard, the original IEEE and The Open Group
8768 Standard is the referee document.
8769 The original Standard can be obtained online at
8770 .Lk http://www.opengroup.org/unix/online.html OpenGroup.org
8771 Redistribution of this material is permitted so long as this notice
8779 .An "Christos Zoulas" ,
8780 .An "Gunnar Ritter" ,
8781 .An "Steffen Nurpmeso" Aq Mt s-nail-users@lists.sourceforge.net
8783 .Mt s-mailx@sdaoden.eu ) .
8789 The character set conversion uses and relies upon the
8792 Its functionality differs widely between the various system environments
8796 Limitations with IMAP mailboxes are:
8797 It is not possible to edit messages, but it is possible to append them.
8798 Thus to edit a message, create a local copy of it, edit it, append it,
8799 and delete the original.
8800 The line count for the header display is only appropriate if the entire
8801 message has been downloaded from the server.
8802 The marking of messages as `new' is performed by the IMAP server;
8807 will not cause it to be reset, and if the
8809 variable is unset, messages that arrived during a session will not be
8810 in state `new' anymore when the folder is opened again.
8811 Also if commands queued in disconnected mode are committed,
8812 the IMAP server will delete the `new' flag for all messages in the
8814 and new messages will appear as unread when it is selected for viewing
8816 The `flagged', `answered', and `draft' attributes are usually permanent,
8817 but some IMAP servers are known to drop them without notification.
8818 Message numbers may change with IMAP every time before the prompt is
8819 printed if \*(UA is notified by the server that messages have been
8820 deleted by some other client or process.
8821 In this case, `Expunged n messages' is printed, and message numbers may
8825 Limitations with POP3 mailboxes are:
8826 It is not possible to edit messages, they can only be copied and deleted.
8827 The line count for the header display is only appropriate if the entire
8828 message has been downloaded from the server.
8829 The status field of a message is maintained by the server between
8830 connections; some servers do not update it at all, and with a server
8833 command will not cause the message status to be reset.
8838 variable have no effect.
8839 It is not possible to rename or to remove POP3 mailboxes.
8846 is typed while an IMAP or POP3 operation is in progress, \*(UA will wait
8847 until the operation can be safely aborted, and will then return to the
8848 command loop and print the prompt again.
8851 is typed while \*(UA is waiting for the operation to complete, the
8852 operation itself will be cancelled.
8853 In this case, data that has not been fetched yet will have to be fetched
8854 before the next command can be performed.
8855 If the cancelled operation was using an SSL/TLS encrypted channel,
8856 an error in the SSL transport will very likely result and render the
8857 connection unusable.
8860 As \*(UA is a mail user agent, it provides only basic SMTP services.
8861 If it fails to contact its upstream SMTP server, it will not make
8862 further attempts to transfer the message at a later time,
8863 and it does not leave other information about this condition than an
8864 error message on the terminal and an entry in
8866 This is usually not a problem if the SMTP server is located in the same
8867 local network as the computer on which \*(UA is run.
8868 However, care should be taken when using a remote server of an ISP;
8869 it might be better to set up a local SMTP server then which just acts as
8873 \*(UA immediately contacts the SMTP server (or
8875 ) even when operating in
8878 It would not make much sense for \*(UA to defer outgoing mail since SMTP
8879 servers usually provide much more elaborated delay handling than \*(UA
8880 could perform as a client.
8881 Thus the recommended setup for sending mail in
8883 mode is to configure a local SMTP server such that it sends outgoing
8884 mail as soon as an external network connection is available again,
8885 i.e., to advise it to do that from a network startup script.
8891 IMAP support is very basic.
8892 Interrupting an IMAP operation can lead to endless iterations of the
8894 With IMAP, at least if the IMAP cache is used, if multiple
8898 cycles happen without an intervening change of the active mailbox then
8899 \*(UA will at some time loose the ability to keep the local state
8900 up-to-date, meaning that, e.g., messages show up with false numbers, and
8901 including the possibility that messages are accessed via numbers that
8902 are no(t longer) valid, resulting in program crashes.
8903 The solution is to change the active mailbox before that happens :).
8906 from the distribution or the repository.
8908 After deleting some message of a POP3 mailbox the header summary falsely
8909 claims that there are no messages to display, you need to perform
8910 a scroll or dot movement to restore proper state.
8912 In threaded display a power user may encounter crashes very
8913 occasionally (this is may and very).