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 - 2014 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
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17 .\" This product includes software developed by the University of
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19 .\" This product includes software developed by Gunnar Ritter
20 .\" and his contributors.
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41 .ds UV \\%S-nail dirty
45 .\" If not ~/.mailrc, it breaks POSIX compatibility. And adjust main.c.
50 .ds OU [no v15-compat]
55 .Nd send and receive Internet mail
62 .Op Fl a Ar attachment
65 .Op Fl O Ar mta-option
66 .Op Fl q Ar quote-file
68 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
77 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
85 .Op Fl S Ar variable Ns Op Ns = Ns Ar value
91 .Bd -filled -offset indent -compact
92 .Sy Compatibility note:
93 \*(UA and part of its configuration syntax will change in v15.0.
94 Until then there will exist a partial but growing number of
95 backward and forward compatibility configuration options.
96 To choose the new syntax and behaviour already today, the binary option
99 The manual will refer to it via \*(IN and \*(OU as necessary.
102 \*(UA is a mail processing system with a command syntax reminiscent of
104 with lines replaced by messages.
105 It is intended to provide the functionality of the POSIX
107 command and offers (mostly optional) extensions for line editing, IDNA,
108 MIME, S/MIME, SMTP and POP3 (and IMAP).
109 It is usable as a mail batch language.
111 In the following list of supported command line options,
119 are implemented by means of setting the respective option, as via
122 .Bl -tag -width ".Fl A Ar account"
126 command (see below) for
128 after the startup files have been read.
130 Attach the given file to the message.
131 The same filename conventions as described in the section
135 Make standard input and standard output line-buffered.
137 Send blind carbon copies to the given list of addresses.
139 below goes into more detail on that.
141 Send carbon copies to the given list of addresses.
149 variable, which enables debug messages and disables message delivery.
150 Note that this is not a real `sandbox' mode.
154 variable and thus discard messages with an empty message part body.
155 This is useful for sending messages from scripts.
157 Just check if mail is present in the system mailbox.
158 If yes, return an exit status of zero, a non-zero value otherwise.
160 Save the message to send in a file named after the local part of the
161 first recipient's address.
163 Read in the contents of the user's mbox (or the specified file)
165 when \*(UA is quit, it writes undeleted messages back to this file.
168 is interpreted as described for the
173 is not a direct argument to the flag
175 but is instead taken from the command line after option processing has
178 Print a header summary of all messages and exit.
179 A configurable summary view is available via the
185 variable to ignore tty interrupt signals.
186 .It Fl L Ar spec-list
187 Print a header summary of only those messages that match the given
191 .Sx "Specifying messages"
196 option has been given in addition to
198 then printing of the header summary is suppressed,
199 and \*(UA will instead indicate via its exit status wether
201 matched any messages (`0') or not (`1');
202 note that messages are forcefully suppressed, then, and unless verbosity
203 is explicitly enabled (e.g., by using the
209 variable and thus inhibits the initial display of message headers when
210 reading mail or editing a mail folder.
212 Inhibits reading \*(UR upon startup.
213 This option should be activated for \*(UA scripts that are invoked on
214 more than one machine, because the contents of that file may differ
216 (The same behaviour can be achieved by setting the
217 .Ev NAIL_NO_SYSTEM_RC
218 environment variable.)
219 .It Fl O Ar mta-option
220 Pass the given option through to the mail-transfer-agent (MTA).
221 This option has no effect when mail is send via SMTP.
223 .Ns ` Ns Li "-O-h -Onumber" Ns '
224 to specify the hop count for an old
226 Options set like that persist for an entire (interactive) session.
228 Start the message with the contents of the specified file.
229 May be given in send mode only.
231 Opens any folders read-only.
233 Sets the envelope sender address by passing an
236 option to the MTA when a message is send.
239 argument is given it'll be checked for validity and then fixated to
240 the given value, but otherwise the content of the variable
242 will be used for that purpose \(en i.e., it'll be passed through to
245 option whenever a message is send.
246 A valid non-empty value will also be set as if an additional
247 .Ns ` Ns Li "-Sfrom=VALUE" Ns '
248 option had been used and therefore affect sending of messages via SMTP
249 (as a consideration for `From:').
250 .It Fl S Ar variable Ns Op = Ns value
251 Sets the internal option
253 and, in case of a value option, assigns
256 Even though options set via
258 may be overwritten from within resource files,
259 the command line setting will be reestablished after all resources have
262 Specify the subject on the command line
263 (be careful to quote subjects containing spaces).
265 The message to be sent is expected to contain a message header with
266 `To:', `Cc:', or `Bcc:' fields giving its recipients and `Subject:'
267 giving the subject of the message.
268 Recipients and subject specified on the command line are ignored.
270 Read the system mailbox of
272 (appropriate privileges presumed), and `assume to be'
274 in some aspects, e.g. in respect to expansions of `%' etc.
278 Print \*(UA's version and exit.
282 option causes some verbosity (like printing of certificate chains).
283 Using it twice increases the level of verbosity.
285 Enable tilde escapes even if not in interactive mode.
287 This sets multiple options to prepare \*(UA for working in batch mode
288 (most likely in non-interactive mode):
300 it also enables processing of tilde escapes.
301 E.g., the following should send an email message to `alias'.
303 .Dl printf 'm alias\en~s Subject\enBody\en.\enx\en' | \
304 MAILRC=/dev/null s-nail -n -#
308 .\" .Ss "Sending mail" {{{
310 To send a message to one or more people,
311 \*(UA can be invoked with arguments which are the names of people to
312 whom the mail will be sent.
315 es, plain addresses or full address specifications including user names
317 in which case care for proper quoting may be necessary.
318 If this manual refers to a \fIlist of addresses\fR,
319 then \*(UA expects a comma-separated list of such names.
321 .Sx "Recipient address specifications"
322 below explains the interpretation of names in more detail.
323 The user is then expected to type in his message, followed by a
325 at the beginning of a line.
327 .Sx "Replying to or originating mail"
328 describes some features of \*(UA available to help when composing
332 .\" .Ss "Reading mail" {{{
334 In normal usage \*(UA is given no arguments and checks the user's mail
335 out of the post office,
336 then prints out a one line header of each message found.
337 The current message is initially the first message (numbered 1) and can
340 command, which can be abbreviated `p'.
341 The commands `p+' and `p\-' move forward to the next and backward to the
342 previous message, respectively, and messages can be addressed directly
343 by specifying their message number, as in `p 1'.
346 .\" .Ss "Disposing of mail" {{{
347 .Ss "Disposing of mail"
348 After examining a message the user can
353 Deletion causes the \*(UA program to forget about the message.
354 This is not irreversible;
357 (`u') the message by giving its number,
358 or the \*(UA session can be ended by giving the
361 Deleted messages will, however, usually disappear never to be seen
365 .\" .Ss "Specifying messages" {{{
366 .Ss "Specifying messages"
367 Commands such as print and delete can be given a list of message numbers
368 as arguments to apply to a number of messages at once.
370 .Ns ` Ns Li "delete 1 2" Ns '
371 deletes messages 1 and 2,
373 .Ns ` Ns Li "delete 1-5" Ns '
374 will delete the messages 1 through 5.
375 In sorted or threaded mode (see the
380 .Ns ` Ns Li "delete 1-5" Ns '
381 will delete the messages that are located between (and including)
382 messages 1 through 5 in the sorted/threaded order, as shown in the
384 The following special message names exist:
386 .Bl -tag -width ".It .Ar :n:u"
390 All old messages (any not in state read or new).
394 All deleted messages (for the
400 All `flagged' messages.
402 All answered messages
407 All messages marked as draft.
409 \*(OP All messages classified as spam.
413 The message that was previously the current message.
415 The parent message of the current message,
416 that is the message with the Message-ID given in the `In-Reply-To:' field
417 or the last entry of the `References:' field of the current message.
419 The next previous undeleted message,
420 or the next previous deleted message for the
423 In sorted/threaded mode,
424 the next previous such message in the sorted/threaded order.
426 The next undeleted message,
427 or the next deleted message for the
430 In sorted/threaded mode,
431 the next such message in the sorted/threaded order.
433 The first undeleted message,
434 or the first deleted message for the
437 In sorted/threaded mode,
438 the first such message in the sorted/threaded order.
441 In sorted/threaded mode,
442 the last message in the sorted/threaded order.
445 selects the message addressed with
449 is any other message specification,
450 and all messages from the thread that begins at it.
451 Otherwise it is identical to
456 the thread beginning with the current message is selected.
460 All messages that were included in the message list for the previous
462 .It Ar / Ns Ar string
463 All messages that contain
465 in the subject field (case ignored).
472 the string from the previous specification of that type is used again.
473 .It Xo Op Ar @ Ns Ar name-list Ns
476 All messages that contain the given case-insensitive search
478 ession; if the \*(OPal regular expression (see
482 will be interpreted as one if any of the `magic'al regular expression
485 .Ar @ Ns Ar name-list
486 part is missing, the search is restricted to the subject field body,
489 specifies a comma-separated list of header fields to search, as in
491 .Dl '@to,from,cc@Someone i ought to know'
493 The special names `body' and `text' can be used to search in message
494 bodies \(en whereas the former searches only the body, the latter form
495 also performs a fulltext search in the header fields.
496 In order to search for a string that includes a `@' (commercial at)
499 is effectively non-optional, but may be given as the empty string.
503 By default, this is a case-sensitive search for the complete email
508 only the local part of the addresses is evaluated for the comparison.
512 a case-sensitive search for the complete real name of a sender is
515 .Ns ` Ns Li "(from address)" Ns '
516 expression can be used instead if substring matches are desired.
520 \*(OP IMAP-style SEARCH expressions may also be used.
521 This addressing mode is available with all types of folders;
522 for folders not located on IMAP servers,
523 or for servers unable to execute the SEARCH command,
524 \*(UA will perform the search locally.
525 Strings must be enclosed by double quotes `"' in their entirety
526 if they contain white space or parentheses;
528 only backslash `\e' is recognized as an escape character.
529 All string searches are case-insensitive.
530 When the description indicates that the `envelope' representation of an
531 address field is used,
532 this means that the search string is checked against both a list
535 .Dl ( \*q Ns name Ns \*q \*q Ns source Ns \*q \*q Ns \
536 local-part Ns \*q \*q Ns domain-part Ns \*q )
539 and the addresses without real names from the respective header field.
540 These search expressions can be nested using parentheses, see below for
542 .Bl -tag -width ".It .Ar :n:u"
544 All messages that satisfy the given
546 .It Ar ( criterion1 criterion2 ... criterionN )
547 All messages that satisfy all of the given criteria.
548 .It Ar ( or criterion1 criterion2 )
549 All messages that satisfy either
554 To connect more than two criteria using `or',
555 (or) specifications have to be nested using additional parentheses,
557 .Ns ` Ns Li "(or a (or b c))" Ns ',
559 .Ns ` Ns Li "(or a b c)" Ns '
561 .Ns ` Ns Li "((a or b) and c)" Ns '.
562 For a simple `or' operation of independent criteria on the lowest
564 it is possible to achieve similar effects by using three separate
566 .Ns ` Ns Li "(a) (b) (c)" Ns '.
567 .It Ar ( not criterion )
568 All messages that do not satisfy
570 .It Ar ( bcc \*q Ns Ar string Ns Ar \*q )
571 All messages that contain
573 in the `envelope' representation of the `Bcc:' field.
574 .It Ar ( cc \*q Ns Ar string Ns Ar \*q )
575 All messages that contain
577 in the `envelope' representation of the `Cc:' field.
578 .It Ar ( from \*q Ns Ar string Ns Ar \*q )
579 All messages that contain
581 in the `envelope' representation of the `From:' field.
582 .It Ar ( subject \*q Ns Ar string Ns Ar \*q )
583 All messages that contain
585 in the `Subject:' field.
586 .It Ar ( to \*q Ns Ar string Ns Ar \*q )
587 All messages that contain
589 in the `envelope' representation of the `To:' field.
590 .It Ar ( header name \*q Ns Ar string Ns Ar \*q )
591 All messages that contain
596 .It Ar ( body \*q Ns Ar string Ns Ar \*q )
597 All messages that contain
600 .It Ar ( text \*q Ns Ar string Ns Ar \*q )
601 All messages that contain
603 in their header or body.
604 .It Ar ( larger size )
605 All messages that are larger than
608 .It Ar ( smaller size )
609 All messages that are smaller than
612 .It Ar ( before date )
613 All messages that were received before
615 which must be in the form
616 .Li "d[d]-mon-yyyy" ,
617 where `d' denotes the day of the month as one or two digits,
618 `mon' is the name of the month \(en one of
619 `Jan', `Feb', `Mar', `Apr', `May', `Jun',
620 `Jul', `Aug', `Sep', `Oct', `Nov', or `Dec',
621 and `yyyy' is the year as four digits, e.g., "28-Dec-2012".
623 All messages that were received on the specified date.
624 .It Ar ( since date )
625 All messages that were received since the specified date.
626 .It Ar ( sentbefore date )
627 All messages that were sent on the specified date.
628 .It Ar ( senton date )
629 All messages that were sent on the specified date.
630 .It Ar ( sentsince date )
631 All messages that were sent since the specified date.
633 The same criterion as for the previous search.
634 This specification cannot be used as part of another criterion.
635 If the previous command line contained more than one independent
636 criterion then the last of those criteria is used.
640 .\" .Ss "Replying to or originating mail" {{{
641 .Ss "Replying to or originating mail"
644 can be used to set up a response to a message,
645 sending it back to the person who it was from.
646 Text the user types in, up to an end-of-file,
647 defines the contents of the message.
648 While the user is composing a message \*(UA treats lines beginning with
649 the character `~' specially.
650 For instance, typing `~m' (alone on a line) will place a copy of the
651 current message into the response, each line prefixed by the value of
653 Other escapes will set up subject fields,
654 add and delete recipients to the message,
656 and allow the user to escape to an editor to revise the message
657 or to a shell to run some commands.
658 (These options are given in the summary below.)
661 .\" .Ss "Ending a mail processing session" {{{
662 .Ss "Ending a mail processing session"
663 The user can end a \*(UA session by issuing the
666 Messages which have been examined go to the user's mbox file unless they
668 in which case they are discarded.
669 Unexamined messages go back to the post office.
673 When command line history is tracked, an updated history file is
675 None of these actions is performed when the command
677 (`x') is used instead of
682 .\" .Ss "Personal and systemwide distribution lists" {{{
683 .Ss "Personal and systemwide distribution lists"
684 It is possible to create personal distribution lists so that,
685 for instance, the user can send mail to `cohorts'
686 and have it go to a group of people.
687 Such lists can be defined via the
689 command by, e.g., placing lines like
691 .Dl alias cohorts bill ozalp jkf mark kridle@ucbcory
693 in the file \*(ur in the user's home directory.
696 without arguments lists all the currently known aliases.
698 Please note that this mechanism has nothing in common with the system
699 wide aliases that may be used by the local MTA (mail-transfer-agent)
700 and are often tracked in a file
707 Personal aliases will be expanded by \*(UA before the message is sent.
708 They are a convenient alternative to specifying each addressee by
712 .\" .Ss "Recipient address specifications" {{{
713 .Ss "Recipient address specifications"
714 When an address is used to name a recipient (in `To:', `Cc:', or `Bcc:'),
715 names of local mail folders and pipes to external commands may also be
716 specified \(en the message text is then written to them.
717 The rules are: Any name which starts with a `|' (vertical bar) character
718 specifies a pipe \(en the command string following the `|' is executed
719 and the message is sent to its standard input;
720 any other name which contains a `@' (at sign) character is treated as
722 any other name which starts with a `+' (plus sign) character specifies
724 any other name which contains a `/' (slash) character but no `!'
725 (exclamation mark) or `%' (percent sign) character before also specifies
727 what remains is treated as a mail address.
728 Compressed folders are handled as described for the
733 .\" .Ss "Network mail (Internet / ARPA, UUCP, Berknet)" {{{
734 .Ss "Network mail (Internet / ARPA, UUCP, Berknet)"
737 for a description of network addresses.
738 If support for IDNA (internationalized domain names for applications)
739 has been compiled into \*(UA,
740 then the domain name part of network addresses will be converted via
741 IDNA mechanisms as necessary, effectively treating it as a name in the
745 for the complete picture about character sets.
747 \*(UA has a number of options which can be set in the \*(ur file
748 to alter its behavior; e.g.,
753 .Ic "set idna-disable"
754 will disable the mentioned IDNA conversion even if support is available.
755 (These options are summarized below.)
758 .\" .Ss "MIME types" {{{
760 For any outgoing attachment \*(UA tries to determine the content type.
761 It does this by reading MIME type files whose lines have the following
764 .Dl type/subtype extension [extension ...]
766 where `type/subtype' are strings describing the file contents,
767 and `extension' is the part of a filename starting after the last dot.
768 Any line not immediately beginning with an ASCII alphabetical character
771 .Va mimetypes-load-control
772 can be used to control the sources of MIME types, and the
774 command can be used to show the list of mime types known to \*(UA.
775 If there is a match with the `extension' of the file to attach,
776 the given `type/subtype' pair is used.
777 Otherwise, or if the filename has no extension,
778 the content types `text/plain' or `application/octet-stream' are used,
779 dependent upon file content inspection.
781 .Va mime-allow-text-controls .
784 .\" .Ss "Character sets" {{{
786 \*(UA normally detects the character set of the terminal by using
787 mechanisms that are controlled by the `LC_CTYPE' locale setting,
788 if such are supported; the variable
790 will be set to the detected terminal character set and will thus
791 show up in the output of the command
796 value is not overwritten by this detection mechanism;
797 this feature must be used if the detection doesn't work properly,
798 and it may be used to adjust the name of the locale character set.
799 E.g., on BSD systems one may use a locale with the character set
800 `ISO8859-1', which is not a valid name for this character set;
801 to be on the safe side, one may set
803 to the correct name, `ISO-8859-1'.
805 Note that changing the value doesn't mean much beside that,
806 since several aspects of the real character set are implied by the
807 locale environment of the system,
808 and that stays unaffected by the content of an overwritten
811 (This is mostly an issue when interactively using \*(UA, though.
812 It is actually possible to send mail in a completely "faked" locale
815 If no character set conversion capabilities have been compiled into
818 library has been found), then
820 will be the only supported character set,
821 it is simply assumed that it can be used to exchange 8 bit messages,
822 and the rest of this section does not apply;
823 it may however still be necessary to explicitly set it if automatic
824 detection fails, since in that case it defaults to `ISO-8859-1'.
826 When reading messages, their text is converted into
828 as necessary in order to display them on the users terminal.
829 Unprintable characters and illegal byte sequences are detected
830 and replaced by proper substitution characters
833 was set once \*(UA was started).
835 When sending messages all their parts and attachments are classified.
836 Whereas no character set conversion is performed on those parts which
837 appear to be binary data,
838 the character set being used must be declared within the MIME header of
839 an outgoing text part if it contains characters that do not conform to
840 the set of characters that are allowed by the email standards.
841 Permissible values for character sets can be declared using the
845 which defines a catch-all last-resort fallback character set that is
846 implicitly appended to the list of character-sets in
849 All the specified character sets are tried in order unless the
850 conversion of the part or attachment succeeds.
851 If none of the tried (8 bit) character sets is capable to represent the
852 content of the part or attachment,
853 then the message will not be sent and its text will be saved to
855 In general, if the message `Cannot convert from a to b' appears, either
856 some characters are not appropriate for the currently selected
857 (terminal) character set,
858 or the needed conversion is not supported by the system.
859 In the first case, it is necessary to set an appropriate `LC_CTYPE'
860 locale and/or the variable
863 The best results are usually achieved when \*(UA is run in a UTF-8
864 locale on a UTF-8 capable terminal,
865 in which case the full Unicode spectrum of characters is available.
866 In this setup characters from various countries can be displayed,
867 while it is still possible to use more simple character sets for sending
868 to retain maximum compatibility with older mail clients.
871 .\" .Ss "Command line editor" {{{
872 .Ss "Command line editor"
873 \*(OP \*(UA can be configured to support a command line editor and
874 command history lists which are saved in between sessions.
875 One may link against fully-fledged external libraries
876 .Ns ( Ns Xr readline 3 ,
878 ) or use \*(UA's own command line editor NCL (nail-command-line)
879 instead, which should work in all environments which comply to ISO
880 C (ISO/IEC 9899:1990/Amendment 1:1995).
881 When an external library is used, interactive behaviour of \*(UA relies
882 on that library and may not correspond one-to-one to what is described
885 Regardless of the actually used command line editor history entries
886 will be created for lines entered in command mode only, and creation of
887 such an entry can be forcefully suppressed by starting the line with
889 Note that history handling is by itself an optional feature and may
890 therefore not be available.
891 For more information see the documentation of the options
894 .Va line-editor-disable ,
899 The builtin \*(UA command line editor supports the following operations;
900 the notation `^-character' stands for the combination of the `control'
901 key plus the mentioned character, e.g., `^A' means "hold control key
902 while adding an A key on top of it":
903 .Bl -tag -width "^M^"
905 Go to the start of the line.
907 Move the cursor backward one character.
909 Forward delete the character under the cursor;
910 quits \*(UA if used on the empty line, unless the
914 Go to the end of the line.
916 Move the cursor forward one character.
918 Cancel current operation, full reset.
919 If there is an active history search or tabulator expansion then this
920 command will first reset that, reverting to the former line content;
921 thus a second reset is needed for a full reset in this case.
922 In all cases \*(UA will reset a possibly used multibyte character input
925 The same as `backspace': backward delete one character.
927 \*(OP The same as `horizontal tabulator': try to expand the "word"
929 Here "expansion" refers to the \*(UA expansion, as documented for
931 and thus includes shell word expansion (as a last step).
932 I.e., this is \*(UA "expansion", not what one usually expects from
935 The same as `ENTER': complete this line of input.
937 Delete all characters from the cursor to the end of the line.
941 \*(OP Go to the next history entry.
943 \*(OP Go to the previous history entry.
945 \*(OP Complete the current line from (the remaining older) history entries.
947 The same as `^A' followed by `^K'.
949 Delete the characters from the one preceding the cursor to the preceding
952 Move the cursor forward one word boundary.
954 Move the cursor backward one word boundary.
957 If problems with commands that are based upon rightwise movement are
958 encountered, adjustments of the option
959 .Va line-editor-cursor-right
960 may solve the problem, as documented for it.
962 If the terminal produces key sequences which are compatible with
964 then the left and right cursor keys will map to `^B' and `^F',
965 respectively, the up and down cursor keys will map to `^P' and `^N',
966 and the Home/End/PgUp/PgDown keys will call the
968 command with the respective arguments `0', `$', `-' and `+'
969 (i.e., perform scrolling through the header summary list).
972 .\" .Ss "Coloured message display" {{{
973 .Ss "Coloured message display"
974 \*(OP \*(UA can be configured to support coloured message display.
975 Colours are used only when the
977 environment variable is set and the terminal type can be found in
979 Beyond that, if a command requires to output through the
985 must be mentioned in the variable
987 otherwise no colours will be used regardless of the actual terminal type.
989 "Coloured message display" can be configured through font attributes
990 (`ft=' \(en `bold', `invers' and `underline'), foreground (`fg=') and
991 background (`bg=') colours (`black', `blue', `green', `red', `brown',
992 `magenta', `cyan' and `white').
993 Multiple specifications can be joined in a comma separated list, as in
995 .Dl set colour-msginfo="ft=bold,fg=magenta,bg=cyan"
997 Options to be set are
999 .Va colour-partinfo ,
1003 .Va colour-uheader ,
1005 .Va colour-user-headers ,
1006 which is a list of headers to be colourized via
1008 instead of the default
1010 To forcefully disable colours, set
1011 .Va colour-disable .
1014 .\" .Ss "Commands" {{{
1016 Each command is typed on a line by itself,
1017 and may take arguments following the command word.
1018 The command need not be typed in its entirety \(en
1019 the first command which matches the typed prefix is used.
1022 prints a sorted list of available commands, and the command
1024 when given an argument, will show a documentation string for the
1026 .Ns ` Ns Ic ? Ns Ar unc Ns ' ;
1027 documentation strings are however \*(OP.)
1029 For commands which take message lists as arguments,
1030 if no message list is given,
1031 then the next message forward which satisfies the command's requirements
1033 If there are no messages forward of the current message,
1034 the search proceeds backwards,
1035 and if there are no good messages at all,
1036 \*(UA types `no applicable messages' and aborts the command.
1037 If the command begins with a `#' (number sign) character,
1038 the line is ignored.
1040 The arguments to commands can be quoted, using the following methods:
1041 .Bl -bullet -offset indent
1043 An argument can be enclosed between paired double-quotes `"argument"' or
1044 single-quotes `'argument'';
1045 any white space, shell word expansion, or backslash characters (except
1046 as described next) within the quotes are treated literally as part of
1048 A double-quote will be treated literally within single-quotes and vice
1050 Inside such a quoted string the actually used quote character can be
1051 used nonetheless by escaping it with a backslash `\\', as in
1054 An argument that is not enclosed in quotes, as above, can usually still
1055 contain space characters if those spaces are backslash-escaped.
1057 A backslash outside of the enclosing quotes is discarded
1058 and the following character is treated literally as part of the argument.
1060 An unquoted backslash at the end of a command line is discarded and the
1061 next line continues the command.
1064 Filenames, where expected, are subsequently subjected to the following
1065 transformations, in sequence:
1066 .Bl -bullet -offset indent
1068 If the filename begins with an unquoted plus sign, and the
1070 variable is defined,
1071 the plus sign will be replaced by the value of the
1073 variable followed by a slash.
1076 variable is unset or is set to null, the filename will be unchanged.
1078 Shell word expansions are applied to the filename.
1079 If more than a single pathname results from this expansion and the
1080 command is expecting one file, an error results.
1084 The following commands are provided:
1085 .Bl -tag -width ".Ic account"
1087 Interprets the remainder of the word as a macro name and passes it
1091 .Ns ` Ns Ic ~ Ns Ar mymacro Ns '
1092 is a shorter synonym for
1093 .Ns ` Ns Ic call Ar mymacro Ns ' .
1095 Print out the preceding message.
1096 If given a numeric argument n,
1097 goes to the n'th previous message and prints it.
1099 Prints a brief summary of commands.
1100 \*(OP Given an argument a synopsis for the command in question is
1103 Executes the shell (see
1107 ) command which follows.
1113 (ac) Creates, selects or lists an email account.
1114 An account is formed by a group of commands,
1115 primarily of those to set variables.
1117 of which the second is a `{',
1118 the first argument gives an account name,
1119 and the following lines create a group of commands for that account
1120 until a line containing a single `}' appears.
1121 With one argument the previously created group of commands for the
1122 account name is executed, and a
1124 command is executed for the system mailbox or inbox of that account.
1125 Without arguments the list of accounts and their contents are printed.
1127 .Bd -literal -offset indent
1129 set folder=imaps://mylogin@imap.myisp.example
1131 set from="myname@myisp.example (My Name)"
1132 set smtp=smtp://mylogin@smtp.myisp.example
1136 creates an account named `myisp' which can later be selected by
1137 specifying `account myisp'.
1138 The special account `null' (case-insensitive) always exists.
1140 can be used to localize account settings.
1141 Accounts can be deleted via
1144 (a) With no arguments, prints out all currently-defined aliases.
1145 With one argument, prints out that alias.
1146 With more than one argument,
1147 creates a new alias or changes an old one.
1149 can be used to delete aliases.
1151 (alt) The alternates command is useful if the user has accounts on
1153 It can be used to inform \*(UA that the listed addresses all belong to
1155 When replying to messages \*(UA will not send a copy of the message
1156 to any of the addresses listed on the alternates list.
1157 If the alternates command is given with no argument,
1158 the current set of alternate names is displayed.
1160 (ans) Takes a message list and marks each message as having been
1162 This mark has no technical meaning in the mail system;
1163 it just causes messages to be marked in the header summary,
1164 and makes them specially addressable.
1166 \*(OP Only applicable to cached IMAP mailboxes;
1167 takes a message list and reads the specified messages into the IMAP
1170 Calls a macro (see the
1177 \*(OP Only applicable to S/MIME signed messages.
1178 Takes a message list and a file name and saves the certificates
1179 contained within the message signatures to the named file in both
1180 human-readable and PEM format.
1181 The certificates can later be used to send encrypted messages to the
1182 respective message senders by setting
1183 .Va smime-encrypt-USER@HOST
1186 (ch) Changes the user's working directory to the specified one,
1187 or to the user's login directory, if none was given.
1190 Only applicable to threaded mode.
1191 Takes a message list and makes all replies to these messages invisible
1192 in header summaries,
1193 unless they are in state `new'.
1195 \*(OP (conn) If operating in disconnected mode on an IMAP mailbox,
1196 switch to online mode and connect to the mail server while retaining the
1198 See the description of the
1200 variable for more information.
1202 (c) The copy command does the same thing that
1204 does except that it does not mark the given messages for deletion when
1206 Compressed files and IMAP mailboxes are handled as described for the
1212 but saves the messages in a file named after the local part of the
1213 sender address of the first message.
1215 Print the current working directory.
1217 \*(OP (dec) For unencrypted messages,
1218 this command is identical to
1220 Encrypted messages are first decrypted, if possible, and then copied.
1222 \*OP (Dec) Similar to
1224 but saves the messages in a file named after the local part of the
1225 sender address of the first message.
1227 (def) Without arguments the current list of macros, including their
1228 content, is printed.
1229 If arguments are given this command defines a macro.
1230 A macro definition is a sequence of commands in the following form:
1231 .Bd -literal -offset indent
1240 A defined macro can be explicitly invoked using
1244 or it can be implicitly invoked by setting the
1247 .Va folder-hook-fullname
1249 Macros can be deleted via
1252 (d) Takes a list of messages as argument and marks them all as deleted.
1253 Deleted messages will not be saved in `mbox',
1254 nor will they be available for most other commands.
1259 \*(OP (disco) If operating in online mode on an IMAP mailbox,
1260 switch to disconnected mode while retaining the mailbox status.
1261 See the description of the
1264 A list of messages may optionally be given as argument;
1265 the respective messages are then read into the cache before the
1266 connection is closed.
1267 Thus `disco *' makes the entire mailbox available for disconnected use.
1268 .It Ic dp Ns \ or Ic dt
1269 Deletes the current message and prints the next message.
1270 If there is no next message, \*(UA says `at EOF'.
1272 Takes a message list and marks each given message as a draft.
1273 This mark has no technical meaning in the mail system;
1274 it just causes messages to be marked in the header summary,
1275 and makes them specially addressable.
1277 Echoes its arguments,
1278 resolving special names as documented for the command
1280 The escape sequences `\ea', `\eb', `\ec', `\ef', `\en', `\er', `\et',
1281 `\ev', `\e\e', and `\e0octal-num\fR' are interpreted just as they are by
1283 (proper quoting provided).
1285 (e) Point the text editor at each message from the given list in turn.
1286 Modified contents are discarded unless the
1295 conditional \(em if the condition of a preceeding
1297 was false, check the following condition and execute the following block
1298 if it evaluates true.
1305 conditional \(em if none of the conditions of the preceeding
1309 commands was true, the
1318 conditional execution block.
1320 (ex or x) Effects an immediate return to the Shell without modifying the
1321 user's system mailbox, his `mbox' file, or his edit file in
1323 as well as a possibly tracked command line editor history file.
1325 Print the list of features that have been compiled into \*(UA.
1330 (fl) Takes a message list and marks the messages as `flagged' for
1331 urgent/special attention.
1332 This mark has no technical meaning in the mail system;
1333 it just causes messages to be highlighted in the header summary,
1334 and makes them specially addressable.
1336 (fold) The folder command switches to a new mail file or folder.
1337 With no arguments, it tells the user which file he is currently reading.
1338 If an argument is given, it will write out changes (such as deletions)
1339 the user has made in the current file and read in the new file.
1340 Some special conventions are recognized for the
1343 .Bl -tag -offset indent -width ".Ar %:filespec"
1345 (number sign) means the previous file,
1347 (percent sign) means the invoking user's system mailbox
1352 means the system mailbox of `user'
1353 (and never the value of
1355 regardless of its actual setting),
1357 (ampersand) means the invoking user's `mbox' file (see
1361 means a `file' in the
1365 expands to the same value as `filespec',
1366 but the file is handled as a system mailbox by, e.g., the
1373 If the name matches one of the strings defined with the command
1375 it is replaced by its long form and expanded.
1376 If the name ends with `.gz', `.bz2' or `.xz' it is treated as being
1383 If `name' refers to a directory with the subdirectories `tmp', `new',
1384 and `cur', then it is treated as a folder in `maildir' format.
1387 .Dl \*(IN protocol://[user[:password]@]host[:port][/path]
1388 .Dl \*(OU protocol://[user@]host[:port][/path]
1390 is taken as an Internet mailbox specification.
1391 The \*(OPally supported protocols are `imap' (IMAP v4r1), `imaps'
1392 (IMAP with SSL/TLS encrypted transport), `pop3' (POP3) and `pop3s' (POP3
1393 with SSL/TLS encrypted transport).
1394 The `[/path]' part is valid only for IMAP; there it defaults to `INBOX'.
1396 \*(IN If `user' or `password' contain special characters, in particular
1397 whitespace, `/', `:' or `%', they must be specified in URL notation
1400 may be helpful for preparation).
1401 If no `user' is specified in the URL, the
1403 variable chain is inspected; likewise the
1405 variable chain for the password.
1407 \*(OU If `user' contains special characters, in particular `/' or `%',
1408 they must be escaped in URL notation \(en the command
1410 can be used to show the necessary conversion.
1411 The optional `path' part applies to IMAP only;
1412 if it is omitted, the default `INBOX' is used.
1414 If \*(UA is connected to an IMAP server,
1415 a name of the form `@mailbox' refers to the `mailbox' on that server,
1416 but otherwise a `@' prefix has no special meaning.
1418 With no arguments, list the names of the folders in the folder directory.
1419 With an existing folder as an argument,
1420 lists the names of folders below the named folder;
1421 e.\|g. the command `folders @' lists the folders on the base level of
1422 the current IMAP server.
1423 See also the variable
1424 .Va imap-list-depth .
1428 but saves the message in a file named after the local part of the first
1429 recipient's address.
1433 but saves the message in a file named after the local part of the first
1434 recipient's address.
1438 but responds to all recipients regardless of the
1443 .It Ic followupsender
1446 but responds to the sender only regardless of the
1452 (fwd) Takes a message and the address of a recipient
1453 and forwards the message to him.
1454 The text of the original message is included in the new one,
1455 with the value of the
1457 variable printed before.
1462 commands specify which header fields are included in the new message.
1463 Only the first part of a multipart message is included unless the
1464 .Va forward-as-attachment
1469 but saves the message in a file named after the local part of the
1470 recipient's address.
1472 (f) Takes a list of messages and prints their message headers,
1473 piped through the pager if the output does not fit on the screen.
1475 Specifies which header fields are to be ignored with the command
1477 This command has no effect when the
1478 .Va forward-as-attachment
1481 Specifies which header fields are to be retained with the command
1486 This command has no effect when the
1487 .Va forward-as-attachment
1490 Without arguments it lists all currently defined command aliases,
1492 With two arguments it defines a new command alias: the first argument is
1493 the name under which the second should be accessible.
1494 The content of the second argument can be just about anything.
1495 A ghost can be used everywhere a normal command can be used, but always
1496 takes precedence; any arguments that are given to the command alias are
1497 joined onto the alias content, and the resulting string forms the
1498 command line that is, in effect, executed.
1502 .Dl ? ghost ls '!ls -latro'
1505 (h) Lists the current range of headers, which is an 18-message group.
1506 If a `+' argument is given the next 18-message group is printed,
1507 likewise the previous is printed if the argument was `-'.
1515 the list of history entries;
1518 argument selects and shows the respective history entry \(en
1519 press `ENTER' to accept it, and the history entry will become the new
1521 The default mode if no arguments are given is
1524 (ho, also preserve) Takes a message list and marks each message therein
1525 to be saved in the user's system mailbox instead of in `mbox'.
1526 Does not override the
1529 \*(UA deviates from the POSIX standard with this command,
1532 command issued after
1534 will display the following message, not the current one.
1536 Part of the nestable
1541 conditional execution construct \(em if the given condition is false
1542 execute the following block.
1543 .Bd -literal -offset indent
1551 Note that POSIX only supports the conditions `[Rr]eceive', `[Ss]end'
1552 and `[Tt]erm' (execute if standard input is a tty).
1553 Extensions are `0' (never execute) and `1' (always execute);
1554 it is also possible to conditionalize upon wether an option is set,
1555 or set to a specific value, by using the `$' conditional trigger, e.g.:
1556 .Bd -literal -offset indent
1560 if $encoding == "UTF-8"
1563 if $encoding != "UTF-8"
1568 The first form simply checks wether an option is set, the other two also
1569 perform value content comparison (equality and non-equality,
1570 respectively); an unset value is treated as the empty string, then.
1571 The \*(OPal regular expression support adds `=~' and `!~' tests, which
1572 treat the right hand side as a regular expression, e.g., `^UTF.*' (see
1576 Add the list of header fields named to the ignored list.
1577 Header fields in the ignore list are not printed on the terminal when
1578 a message is printed.
1579 This command is very handy for suppression of certain machine-generated
1585 commands can be used to print a message in its entirety, including
1587 It lists the current set of ignored fields if no arguments were given.
1589 \*(OP Sends command strings directly to the current IMAP server.
1590 \*(UA operates always in IMAP `selected state' on the current mailbox;
1591 commands that change this will produce undesirable results and should be
1593 Useful IMAP commands are:
1594 .Bl -tag -offset indent -width ".Ic getquotearoot"
1596 Takes the name of an IMAP mailbox as an argument and creates it.
1598 (RFC 2087) Takes the name of an IMAP mailbox as an argument
1599 and prints the quotas that apply to the mailbox.
1600 Not all IMAP servers support this command.
1602 (RFC 2342) Takes no arguments and prints the Personal Namespaces,
1603 the Other User's Namespaces and the Shared Namespaces.
1604 Each namespace type is printed in parentheses;
1605 if there are multiple namespaces of the same type,
1606 inner parentheses separate them.
1607 For each namespace a prefix and a hierarchy separator is listed.
1608 Not all IMAP servers support this command.
1614 Prints the names of all available commands, alphabetically sorted.
1616 Can only be used inside of a macro definition block introduced by
1620 and is interpreted as a boolean (value `0' means false, everything
1622 Any option that had been set while `localopts' was in effect will be
1623 reverted to its former value once the block is left / the `account'
1625 .Bd -literal -offset indent
1626 define temporary_settings {
1636 Note that these options stack upon each other, i.e., if macro1 sets
1637 `localopts' and calls macro2, which explicitly resets `localopts', then
1638 any values set within macro2 will still be cleaned up by macro1.
1642 but saves the message in a file named after the local part of the first
1643 recipient's address.
1645 (m) Takes a (list of) recipient address(es) as (an) argument(s),
1646 or asks on standard input if none were given;
1647 then collects the remaining mail content and sends it out.
1649 The given message list is to be sent to `mbox' when \*(UA is quit.
1650 This is the default action unless the
1653 \*(UA deviates from the POSIX standard with this command,
1656 command issued after
1658 will display the following message, not the current one.
1667 In the former case all sources are loaded first as necessary.
1669 .Va mimetypes-load-control
1670 option can be used to fine-tune which sources are loaded.
1674 but marks the messages for deletion if they were transferred
1677 Takes a message list and invokes the
1679 on that list, printing a form-feed (`\\f') in between messages.
1683 but also prints ignored header fields and all MIME parts.
1687 but moves the messages to a file named after the local part of the
1688 sender address of the first message.
1690 Checks for new mail in the current folder without committing any changes
1692 If new mail is present, a message is printed.
1696 the headers of each new message are also printed.
1698 (n) (like `+' or `ENTER') Goes to the next message in sequence
1700 With an argument list, types the next matching message.
1708 If the current folder is located on an IMAP or POP3 server,
1709 a `NOOP' command is sent.
1710 Otherwise, no operation is performed.
1714 but also pipes ignored header fields and all parts of MIME
1715 `multipart/alternative' messages.
1717 (pi) Takes a message list and a shell command
1718 and pipes the messages through the command.
1719 Without an argument the current message is piped through the command
1726 every message is followed by a formfeed character.
1733 but also prints out ignored header fields and all parts of MIME
1734 `multipart/alternative' messages.
1741 (p) Takes a message list and types out each message on the user's
1743 If the message is a MIME multipart message,
1744 all parts with a content type of `text' or `message' are shown,
1745 the other are hidden except for their headers.
1746 Messages are decrypted and converted to the terminal character set
1749 (q) Terminates the session, saving all undeleted, unsaved messages in
1750 the current `mbox', preserving all messages marked with
1754 or never referenced in his system mailbox,
1755 and removing all other messages from his system mailbox.
1756 If new mail has arrived during the session,
1757 the message `You have new mail' is given.
1758 If given while editing a mailbox file with the command line flag
1760 then the edit file is rewritten.
1761 A return to the shell is effected,
1762 unless the rewrite of edit file fails,
1763 in which case the user can escape with the exit command.
1771 (rem) Removes the named folders.
1772 The user is asked for confirmation in interactive mode.
1774 (ren) Takes the name of an existing folder
1775 and the name for the new folder
1776 and renames the first to the second one.
1777 Both folders must be of the same type
1778 and must be located on the current server for IMAP.
1780 (R) Reply to originator.
1781 Does not reply to other recipients of the original message.
1783 (r) Takes a message list and sends mail to the sender and all recipients
1784 of the specified messages.
1785 The default message must not be deleted.
1789 but responds to all recipients regardless of the
1797 but responds to the sender only regardless of the
1805 but does not add any header lines.
1806 This is not a way to hide the sender's identity,
1807 but useful for sending a message again to the same recipients.
1809 Takes a list of messages and a user name
1810 and sends each message to the named user.
1811 `Resent-From:' and related header fields are prepended to the new copy
1822 .It Ic respondsender
1826 Add the list of header fields named to the retained list.
1827 Only the header fields in the retain list are shown on the terminal when
1828 a message is printed, all other header fields are suppressed.
1833 commands can be used to print a message in its entirety.
1834 The current set of retained fields is shown if
1836 is used without arguments.
1840 but saves the messages in a file named after the local part of the
1841 sender of the first message instead of taking a filename argument.
1843 (s) Takes a message list and a filename and appends each message in turn
1844 to the end of the file.
1845 If no filename is given, the `mbox' file is used.
1846 The filename in quotes, followed by the line count and character count
1847 is echoed on the user's terminal.
1848 If editing a system mailbox the messages are marked for deletion.
1849 Compressed files and IMAP mailboxes are handled as described for the
1851 command line option above.
1864 Header fields thus marked are filtered out when saving a message by
1866 or when automatically saving to `mbox'.
1867 This command should only be applied to header fields that do not contain
1868 information needed to decode the message,
1869 as MIME content fields do.
1870 If saving messages on an IMAP account ignoring fields makes it
1871 impossible to copy the data directly on the server,
1872 thus operation usually becomes much slower.
1882 Header fields thus marked are the only ones saved with a message when
1885 or when automatically saving to `mbox'.
1889 The use of this command is strongly discouraged since it may strip
1890 header fields that are needed to decode the message correctly.
1892 Takes a message list and marks all messages as having been read.
1894 (se) With no arguments, prints all variable values.
1895 Otherwise, sets an option.
1896 Arguments are of the form `option=value' (no space before or after `='),
1897 or plain `option' if there is no value.
1898 Quotation marks may be placed around any part of the assignment
1899 statement to quote blanks or tabs, e.g.,
1901 .Dl set indentprefix="->"
1903 If an argument begins with `no', as in `set nosave',
1904 the effect is the same as invoking the
1906 command with the remaining part of the variable (`unset save').
1910 except that the options are also exported into the program environment;
1911 since this task requires native host support the command will always
1912 report error if that is not available (but still act like
1915 This operation is a no-op unless all resource files have been loaded.
1919 (sh) Invokes an interactive version of the shell.
1921 Defines a shortcut name and its string for expansion,
1922 as described for the
1925 If used without arguments the currently defined shortcuts are printed.
1929 but performs neither MIME decoding nor decryption so that the raw
1930 message text is shown.
1932 Print the size in characters of each message of the given message-list.
1934 Create a sorted representation of the current folder,
1937 command and the addressing modes such that they refer to messages in the
1939 Message numbers are the same as in regular mode.
1943 a header summary in the new order is also printed.
1944 Possible sorting criteria are:
1945 .Bl -tag -offset indent -width "subject"
1947 Sort the messages by their `Date:' field,
1948 that is by the time they were sent.
1950 Sort messages by the value of their `From:' field,
1951 that is by the address of the sender.
1955 the sender's real name (if any) is used.
1957 Sort the messages by their size.
1959 \*(OP Sort the message by their spam score, as has been classified via
1963 Sort the messages by their message status (new, read, old, etc.).
1965 Sort the messages by their subject.
1967 Create a threaded order,
1971 Sort messages by the value of their `To:' field,
1972 that is by the address of the recipient.
1976 the recipient's real name (if any) is used.
1979 If no argument is given,
1980 the current sorting criterion is printed.
1982 The source command reads commands from a file.
1984 \*(OP Takes a list of messages and clears their `is-spam' flag.
1986 \*(OP Takes a list of messages and forces the spam detector to forget it
1987 has ever used them to train its Bayesian filter, wether as `ham' or
1990 \*(OP Takes a list of messages and teaches them to the spam detector as
1992 This also clears the `is-spam' flag of the messages in question.
1994 \*(OP Takes a list of messages and rates them using the configured spam
1995 detector, setting their `is-spam' flag as appropriate.
1996 Note that the messages are not modified, and due to that the rating will
1997 get lost once the mailbox is left.
1998 Refer to the manual section
2000 for the complete picture of spam handling in \*(UA.
2002 \*(OP Takes a list of messages and sets their `is-spam' flag.
2004 \*(OP Takes a list of messages and teaches them to the spam detector as
2006 This also sets the `is-spam' flag of the messages in question.
2008 (th) Create a threaded representation of the current folder,
2009 i.\|e. indent messages that are replies to other messages in the header
2010 display and change the
2012 command and the addressing modes such that they refer to messages in the
2014 Message numbers are the same as in unthreaded mode.
2018 a header summary in threaded order is also printed.
2020 Takes a message list and prints the top few lines of each.
2021 The number of lines printed is controlled by the variable
2023 and defaults to five.
2025 Takes a message list and marks the messages for saving in `mbox'.
2026 \*(UA deviates from the POSIX standard with this command,
2029 command issued after `mbox' will display the following message instead
2032 (T) Identical to the
2039 Delete all given accounts.
2040 An error message is printed if a given account is not defined.
2041 Attempts to delete the currently active account are rejected.
2043 Takes a list of names defined by alias commands
2044 and discards the remembered groups of users.
2046 Takes a message list and marks each message as not having been answered.
2048 (unc) Only applicable to threaded mode.
2049 Takes a message list and makes the message and all replies to it visible
2050 in header summaries again.
2051 When a message becomes the current message,
2052 it is automatically made visible.
2053 Also when a message with collapsed replies is printed,
2054 all of these are automatically uncollapsed.
2056 Undefine all given macros.
2057 An error message is printed if a given macro is not defined.
2059 (u) Takes a message list and marks each message as not being deleted.
2061 Takes a message list and
2062 .Ns un Ns Ic draft Ns
2065 Takes a message list and marks each message as not being
2068 Removes the header field names from the list of ignored fields for the
2072 Removes the header field names from the list of retained fields for the
2076 Remove an existing command
2079 Removes the header field names from the list of ignored fields.
2084 (U) Takes a message list and marks each message as not having been read.
2086 Removes the header field names from the list of retained fields.
2088 Removes the header field names from the list of ignored fields for
2091 Removes the header field names from the list of retained fields for
2094 Takes a list of option names and discards their remembered values;
2100 except that the options are also removed from the program environment;
2101 since this task requires native host support the command will always
2102 report error if that is not available (but still act like
2105 This operation is a no-op unless all resource files have been loaded.
2109 Deletes the shortcut names given as arguments.
2111 Disable sorted or threaded mode
2117 return to normal message order and,
2121 print a header summary.
2126 Decode the given URL-encoded string arguments and show the results.
2128 URL-encode the given arguments and show the results.
2130 Show information about all given options.
2132 \*(OP (verif) Takes a message list and verifies each message.
2133 If a message is not an S/MIME signed message,
2134 verification will fail for it.
2135 The verification process checks if the message was signed using a valid
2137 if the message sender's email address matches one of those contained
2138 within the certificate,
2139 and if the message content has been altered.
2141 (v) Takes a message list and invokes the display editor on each message.
2142 Modified contents are discarded unless the
2146 (w) For conventional messages the body without all headers is written.
2147 The output is decrypted and converted to its native format as necessary.
2148 If the output file exists, the text is appended.
2149 If a message is in MIME multipart format its first part is written to
2150 the specified file as for conventional messages,
2151 and the user is asked for a filename to save each other part.
2152 For convience saving of each part may be skipped by giving an empty value;
2153 the same result can also be achieved by writing it to
2155 For the second and subsequent parts a leading `|' character causes the
2156 part to be piped to the remainder of the user input interpreted as
2158 otherwise the user input is expanded as usually for folders,
2159 e.g., tilde expansion is performed.
2160 In non-interactive mode, only the parts of the multipart message
2161 that have a filename given in the part header are written,
2162 the others are discarded.
2163 The original message is never marked for deletion in the originating
2166 the contents of the destination file are overwritten if the file
2168 No special handling of compressed files is performed.
2173 \*(UA presents message headers in windowfuls as described under the
2176 This command scrolls to the next window of messages.
2177 If an argument is given,
2178 it specifies the window to use.
2179 A number prefixed by `+' or `\-' indicates
2180 that the window is calculated in relation to the current position.
2181 A number without a prefix specifies an absolute window number,
2182 and a `$' lets \*(UA scroll to the last window of messages.
2186 but scrolls to the next or previous window that contains at least one
2187 new or `flagged' message.
2191 .\" .Ss "Tilde escapes" {{{
2193 Here is a summary of the tilde escapes,
2194 which are used to perform special functions when composing messages.
2195 Tilde escapes are only recognized at the beginning of lines.
2196 The name `tilde escape' is somewhat of a misnomer since the actual
2197 escape character can be set by the option
2199 .Bl -tag -width ".Ic ~< filename"
2201 Insert the string of text in the message prefaced by a single `~'.
2202 (If the escape character has been changed,
2203 that character must be doubled
2204 in order to send it at the beginning of a line.)
2205 .It Ic ~! Ar command
2206 Execute the indicated shell
2208 then return to the message.
2210 Same effect as typing the end-of-file character.
2211 .It Ic ~: Ar \*(UA-command Ns \ or Ic ~_ Ar \*(UA-command
2212 Execute the given \*(UA command.
2213 Not all commands, however, are allowed.
2215 Write a summary of command escapes.
2216 .It Ic ~< Ar filename
2219 .It Ic ~<! Ar command
2221 is executed using the shell.
2222 Its standard output is inserted into the message.
2223 .It Ic ~@ Op Ar filename...
2224 With no arguments, edit the attachment list interactively.
2225 If an attachment's file name is left empty,
2226 that attachment is deleted from the list.
2227 When the end of the attachment list is reached,
2228 \*(UA will ask for further attachments until an empty name is given.
2229 If a given file name solely consists of the number sign `#' followed
2230 by a valid message number of the currently active mailbox, the given
2231 message is attached as a MIME `message/rfc822' and the rest of this
2232 section does not apply.
2234 If character set conversion has been compiled into \*(UA, then this mode
2235 gives the user the option to specify input and output character sets,
2236 unless the file extension indicates binary content, in which case \*(UA
2237 asks wether this step shall be skipped for the attachment in question.
2238 If not skipped, then the charset that succeeds to represent the
2239 attachment data will be used in the `charset=' MIME parameter of the
2243 If input and output character sets are specified, then the conversion is
2244 performed on the fly.
2245 The user will be asked repeatedly until the desired conversion succeeds.
2247 If only an output character set is specified, then the input is assumed
2250 charset and will be converted to the given output charset on the fly.
2251 The user will be asked repeatedly until the desired conversion succeeds.
2253 If no character sets are specified at all then the algorithm that is
2254 documented in the section
2255 .Sx "Character sets"
2256 is applied, but directly and on the fly.
2257 The user will be asked repeatedly until the desired conversion succeeds.
2259 Finally, if an input-, but no output character set is specified, then no
2260 conversion is ever performed, but the `charset=' MIME parameter will
2261 still be set to the user input.
2263 The character set selection loop can be left by typing `control-C',
2264 i.e., causing an interrupt.
2265 .\" \*(OU next sentence
2266 Note that before \*(UA version 15.0 this terminates the entire
2267 current attachment selection, not only the character set selection.
2270 Without character set conversion support, \*(UA will ask for the input
2271 character set only, and it'll set the `charset=' MIME parameter to the
2272 given input, if any;
2273 if no user input is seen then the
2275 character set will be used for the `charset=' parameter instead.
2276 Note that the file extension check isn't performed in this mode, since
2277 no conversion will take place anyway.
2279 Note that in non-interactive mode, for reproduceabilities sake, there
2280 will always be two questions for each attachment, regardless of wether
2281 character set conversion is available and what the file extension is.
2282 The first asks for the filename, and the second asks for the input
2283 character set to be passed through to the `charset=' MIME parameter;
2284 no conversion will be tried if there is input to the latter question,
2285 otherwise the usual conversion algorithm, as above, is applied.
2286 For message attachments, the answer to the second question is completely
2291 arguments are specified,
2292 they are treated as a comma separated list of files,
2293 which are all expanded and appended to the end of the attachment list.
2294 (Filenames with commas, or with leading or trailing whitespace can only
2295 be added via the command line or the first method.
2296 Message attachments can only be added via the first method;
2297 filenames which clash with message numbers can only be added via the
2298 command line or the second method.)
2299 In this mode the (text) attachments are assumed to be in
2301 encoding, and will be evaluated as documented in the section
2302 .Sx "Character sets" .
2304 Inserts the string contained in the
2306 variable (same as `~i Sign').
2307 The escape sequences `\et' (tabulator) and `\en' (newline) are understood.
2309 Inserts the string contained in the
2311 variable (same as `~i sign').
2312 The escape sequences `\et' (tabulator) and `\en' (newline) are understood.
2313 .It Ic ~b Ar name ...
2314 Add the given names to the list of blind carbon copy recipients.
2315 .It Ic ~c Ar name ...
2316 Add the given names to the list of carbon copy recipients.
2318 Read the file specified by the
2320 variable into the message.
2322 Invoke the text editor on the message collected so far.
2323 After the editing session is finished,
2324 the user may continue appending text to the message.
2325 .It Ic ~F Ar messages
2326 Read the named messages into the message being sent, including all
2327 message headers and MIME parts.
2328 If no messages are specified, read in the current message.
2329 .It Ic ~f Ar messages
2330 Read the named messages into the message being sent.
2331 If no messages are specified, read in the current message.
2332 Message headers currently being ignored (by the
2336 command) are not included.
2337 For MIME multipart messages,
2338 only the first printable part is included.
2340 Edit the message header fields `From:', `Reply-To:', `Sender:' and
2341 `Organization:' by typing each one in turn and allowing the user to edit
2343 The default values for these fields originate from the
2351 Edit the message header fields `To:', `Cc:', `Bcc:', and `Subject:' by
2352 typing each one in turn and allowing the user to edit the field.
2353 .It Ic ~i Ar variable
2354 Insert the value of the specified variable into the message,
2355 adding a newline character at the end.
2356 The message remains unaltered if the variable is unset or empty.
2357 The escape sequences `\et' (tabulator) and `\en' (newline) are understood.
2358 .It Ic ~M Ar messages
2359 Read the named messages into the message being sent,
2362 If no messages are specified, read the current message.
2363 .It Ic ~m Ar messages
2364 Read the named messages into the message being sent,
2367 If no messages are specified, read the current message.
2368 Message headers currently being ignored (by the
2372 commands) are not included.
2373 For MIME multipart messages,
2374 only the first printable part is included.
2376 Print out the message collected so far,
2377 prefaced by the message header fields
2378 and followed by the attachment list, if any.
2380 Abort the message being sent,
2381 copying it to the file specified by the
2386 .It Ic ~R Ar filename
2387 Read the named file into the message, indented by
2389 .It Ic ~r Ar filename
2390 Read the named file into the message.
2392 Cause the named string to become the current subject field.
2393 .It Ic ~t Ar name ...
2394 Add the given name(s) to the direct recipient list.
2395 .It Ic ~U Ar messages
2396 Like `~m', but exclude all message headers.
2397 .It Ic ~u Ar messages
2398 Like `~f', but exclude all message headers.
2400 Invoke an alternate editor (defined by the
2402 option) on the message collected so far.
2403 Usually, the alternate editor will be a screen editor.
2404 After the editor is quit,
2405 the user may resume appending text to the end of the message.
2406 .It Ic ~w Ar filename
2407 Write the message onto the named file.
2409 the message is appended to it.
2411 Same as `~q', except that the message is not saved at all.
2412 .It Ic ~| Ar command
2413 Pipe the message through the specified filter command.
2414 If the command gives no output or terminates abnormally,
2415 retain the original text of the message.
2418 is often used as a rejustifying filter.
2422 .\" .Ss "Variable options" {{{
2423 .Ss "Variable options"
2424 Options are controlled via
2428 commands, see the corresponding entries for a syntax description.
2429 An option is also set if it is passed to \*(UA as part of the program
2430 environment (this is not restricted to specific variables as in the
2432 A value given in a startup file overrides a value imported from the
2434 Options may be either binary, in which case it is only significant to
2435 see whether they are set or not;
2436 or string, in which case the actual value is of interest.
2439 .\" .Ss "Binary options" {{{
2440 .Ss "Binary options"
2441 The binary options include the following:
2442 .Bl -tag -width ".Va autoprint"
2443 .It Va add-file-recipients
2444 When file or pipe recipients have been specified,
2445 mention them in the corresponding address fields of the message instead
2446 of silently stripping them from their recipient list.
2447 By default such addressees are not mentioned.
2449 Causes only the local part to be evaluated
2450 when comparing addresses.
2452 Causes messages saved in mbox to be appended to the end rather than
2454 This should always be set.
2455 .It Va ask Ns \ or Va asksub
2456 Causes \*(UA to prompt for the subject of each message sent.
2457 If the user responds with simply a newline,
2458 no subject field will be sent.
2460 Causes the prompts for `Cc:' and `Bcc:' lists to appear after the
2461 message has been edited.
2463 If set, \*(UA asks for files to attach at the end of each message.
2464 An empty line finalizes the list.
2466 Causes the user to be prompted for additional carbon copy recipients (at
2467 the end of each message if
2472 An empty line finalizes the list.
2474 Causes the user to be prompted for additional blind carbon copy
2475 recipients (at the end of each message if
2480 An empty line finalizes the list.
2482 \*(OP Causes the user to be prompted if the message is to be signed at
2483 the end of each message.
2486 variable is ignored when this variable is set.
2488 Causes threads to be collapsed automatically when threaded mode is
2493 Causes the delete command to behave like `dp -';
2494 thus, after deleting a message the next one will be typed automatically.
2496 Causes threaded mode (see the
2498 command) to be entered automatically when a folder is opened.
2500 Enables the substitution of `!' by the contents of the last command line
2502 .It Va batch-exit-on-error
2503 If the batch mode has been enabled via the
2505 command line option, then this variable will be consulted whenever \*(UA
2506 completes one operation (returns to the command prompt); if it is set
2507 then \*(UA will terminate if the last operation generated an error.
2509 Causes automatic display of a header summary after executing a
2513 Sets some cosmetical features to traditional BSD style;
2514 has the same affect as setting
2516 and all other variables prefixed with `bsd';
2517 it also changes the meaning of the \*(UA specific `\\&'
2521 Changes the letters printed in the first column of a header summary
2522 to traditional BSD style.
2524 Changes the display of columns in a header summary to traditional BSD
2527 Changes some informational messages to traditional BSD style.
2529 Causes the `Subject:' field to appear immediately after the `To:' field
2530 in message headers and with the `~h' tilde command.
2532 Changes the output format of the
2534 command to traditional BSD style.
2535 .It Va colour-disable
2536 \*(OP Forcefully disable usage of colours.
2537 Also see the section
2538 .Sx "Coloured message display" .
2540 Prints debugging messages and disables the actual delivery of messages.
2543 this option is intended for \*(UA development only.
2545 \*(OP When an IMAP mailbox is selected and this variable is set,
2546 no connection to the server is initiated.
2547 Instead, data is obtained from the local cache (see
2550 Mailboxes that are not present in the cache
2551 and messages that have not yet entirely been fetched from the server
2553 to fetch all messages in a mailbox at once,
2555 .Ns ` Ns Li copy * /dev/null Ns '
2556 can be used while still in connected mode.
2557 Changes that are made to IMAP mailboxes in disconnected mode are queued
2558 and committed later when a connection to that server is made.
2559 This procedure is not completely reliable since it cannot be guaranteed
2560 that the IMAP unique identifiers (UIDs) on the server still match the
2561 ones in the cache at that time.
2564 when this problem occurs.
2565 .It Va disconnected-USER@HOST
2566 The specified account is handled as described for the
2569 but other accounts are not affected.
2571 The binary option dot causes \*(UA to interpret a period alone on a line
2572 as the terminator of a message the user is sending.
2574 If this variable is set then the editor is started automatically when
2575 composing a message in an interactive mode,
2576 as if the `~e' tilde command had been specified.
2579 variable is implied for this automatically spawned editor session.
2581 When a message is edited while being composed,
2582 its header is included in the editable text.
2583 The `To:', `Cc:', `Bcc:', `Subject:', `From:', `Reply-To:', `Sender:',
2584 and 'Organization:' fields are accepted within the header,
2585 other fields are ignored.
2587 If set, an empty mailbox file is not removed.
2588 This may improve the interoperability with other mail user agents
2589 when using a common folder directory.
2591 If the mailbox is empty \*(UA normally prints `No mail for user' and
2593 If this option is set \*(UA starts even with an empty mailbox.
2599 commands and vice-versa.
2600 .It Va forward-as-attachment
2601 Original messages are normally sent as inline text with the
2604 and only the first part of a multipart message is included.
2605 With this option messages are sent as MIME `message/rfc822' attachments
2606 with all of their parts included.
2611 options are ignored when the
2612 .Va forward-as-attachment
2615 When replying to a message \*(UA normally removes the comment parts of
2617 which by convention contain the full names of the recipients.
2618 If this variable is set such stripping is not performed,
2619 and comments are retained.
2621 Causes the header summary to be written at startup and after commands
2622 that affect the number of messages or the order of messages in the
2623 current folder; enabled by default.
2624 The command line option
2628 .It Va history-gabby
2629 \*(OP Add more entries to the history as is normally done.
2630 .It Va history-gabby-persist
2631 \*(OP \*(UAs own NCL will not save the additional (gabby) history
2632 entries in persistent storage unless this variable is also set.
2636 This option is used to hold messages in the system mailbox by default.
2638 \*(OP Can be used to turn off the automatic conversion of domain names
2639 according to the rules of IDNA (internationalized domain names for
2641 Since the IDNA code assumes domain names are specified with the
2643 character set, an UTF-8 locale charset is required to represent
2644 all possible international domain names (before conversion, that is).
2646 Ignore interrupt signals from the terminal while entering messages;
2647 instead echo them as `@' characters and discard the current line.
2649 An option related to
2653 which makes \*(UA refuse to accept a `control-D' as the end of a message.
2654 This option also applies to \*(UA command mode.
2655 .It Va imap-use-starttls
2656 \*(OP Causes \*(UA to issue a `STARTTLS' command to make an unencrypted
2657 IMAP session SSL/TLS encrypted.
2658 This functionality is not supported by all servers,
2659 and is not used if the session is already encrypted by the IMAPS method.
2660 .It Va imap-use-starttls-USER@HOST
2662 .Va imap-use-starttls
2663 for a specific account.
2665 This option causes \*(UA to truncate the user's system mailbox instead
2666 of deleting it when it is empty.
2667 This should always be set since it prevents malicious users from
2668 creating fake mail folders in a world-writable spool directory.
2670 When a message is saved it is usually discarded from the originating
2671 folder when \*(UA is quit.
2672 Setting this option causes all saved message to be retained.
2673 .It Va line-editor-disable
2674 Turn off any enhanced command line editing capabilities (see
2675 .Sx "Command line editor"
2678 When a message is replied to and this variable is set,
2679 it is marked as having been answered.
2680 This mark has no technical meaning in the mail system;
2681 it just causes messages to be marked in the header summary,
2682 and makes them specially addressable.
2683 .It Va message-id-disable
2684 By setting this option the generation of `Message-ID:' can be completely
2685 suppressed, effectively leaving this task up to the mail-transfer-agent
2686 (MTA) or the SMTP server.
2687 (According to RFC 5321 your SMTP server is not required to add this
2688 field by itself, so you should ensure that it accepts messages without
2691 Usually, when a group is expanded that contains the sender,
2692 the sender is removed from the expansion.
2693 Setting this option causes the sender to be included in the group.
2694 .It Va mime-allow-text-controls
2695 When sending messages, each part of the message is MIME-inspected in
2696 order to classify the `Content-Type:' and `Content-Transfer-Encoding:'
2697 that is required to send this part over mail transport, i.e.,
2698 a computation rather similar to what the
2700 command produces when used with the
2704 This classification however treats text files which are encoded in
2705 UTF-16 (often found for HTML files) and similar character sets as binary
2706 octet-streams, forcefully changing any `text/plain' or `text/html'
2707 specification to `application/octet-stream';
2708 if that actually happens, then a yet unset charset MIME parameter is set
2709 to `binary', effectively making it impossible for the receiving MUA to
2710 automatically interpret the contents of the part.
2712 If this option is set, and the data was unambiguously identified as text
2713 data at first glance (by a `.txt' or `.html' file extension), then the
2714 original `Content-Type:' will not be overwritten.
2715 .It Va mime-counter-evidence
2716 Normally the `Content-Type:' field is used to decide how to treat
2717 a messages MIME part.
2718 Some MUAs however don't use
2720 or a similar mechanism to correctly classify content,
2721 but simply specify `application/octet-stream',
2722 even for plain text attachments like `text/diff'.
2723 If this variable is set then \*(UA will use the file extension of
2724 attachments to classify such MIME message parts, if possible.
2726 Causes the filename given in the
2729 and the sender-based filenames for the
2733 commands to be interpreted relative to the directory given in the
2735 variable rather than to the current directory,
2736 unless it is set to an absolute pathname.
2738 If set, each message the
2740 command prints out is followed by a formfeed character.
2742 Send messages to the
2744 command without performing MIME and character set conversions.
2745 .It Va pop3-bulk-load
2746 \*(OP When accessing a POP3 server \*(UA loads the headers of the
2747 messages, and only requests the message bodies on user request.
2748 For the POP3 protocol this means that the message headers will be
2750 If this option is set then \*(UA will download only complete messages
2751 from POP3 servers instead.
2754 a macro that temporarily sets this option, then accesses a POP3 account
2755 that is known to only get small text messages, and then unsets this
2758 \*(OP Unless this variable is set the `APOP' authentication method
2759 will be used when connecting to a POP3 server that advertises support.
2760 The advantage of APOP over `USER/PASS' authentication is that the
2761 password is not sent in clear text over the wire and that only a single
2762 packet is sent for the user/password tuple.
2763 .It Va pop3-no-apop-HOST
2764 \*(IN Disables the `APOP' authentication method for a specific host.
2765 .It Va pop3-no-apop-USER@HOST
2766 Disables the `APOP' authentication method for a specific account.
2767 .It Va pop3-use-starttls
2768 \*(OP Causes \*(UA to issue a `STLS' command to make an unencrypted POP3
2769 session SSL/TLS encrypted.
2770 This functionality is not supported by all servers,
2771 and is not used if the session is already encrypted by the POP3S method.
2772 .It Va pop3-use-starttls-HOST
2774 .Va pop3-use-starttls
2775 for a specific host.
2776 .It Va pop3-use-starttls-USER@HOST
2778 .Va pop3-use-starttls
2779 for a specific account.
2780 .It Va print-all-chars
2781 This option causes all characters to be considered printable.
2782 It is only effective if given in a startup file.
2783 With this option set some character sequences in messages may put the
2784 user's terminal in an undefined state when printed;
2785 it should only be used as a last resort if no working system locale can
2787 .It Va print-alternatives
2788 When a MIME message part of type `multipart/alternative' is displayed
2789 and it contains a subpart of type `text/plain',
2790 other parts are normally discarded.
2791 Setting this variable causes all subparts to be displayed,
2792 just as if the surrounding part was of type `multipart/mixed'.
2794 Suppresses the printing of the version when first invoked.
2795 .It Va quote-as-attachment
2796 If this is set, then the original message is added in its entirety
2797 as a `message/rfc822' MIME attachment when replying to a message.
2798 Note this works regardless of the setting of
2800 .It Va recipients-in-cc
2801 On group replies, specify only the sender of the original mail in `To:'
2802 and mention it's other recipients in the secondary `Cc:'.
2803 .It Va record-resent
2804 If both this variable and the
2811 commands save messages to the
2813 folder as it is normally only done for newly composed messages.
2814 .It Va reply-in-same-charset
2815 If this variable is set \*(UA first tries to use the same character set
2816 of the original message for replies.
2817 If this fails, the mechanism described in
2818 .Sx "Character sets"
2819 is evaluated as usual.
2821 Reverses the sense of
2826 .It Va rfc822-body-from_
2827 This variable can be used to force the display of a so-called `From_'
2828 line for messages that are embedded into an envelope mail via the
2829 `message/rfc822' MIME mechanism.
2831 When the user aborts a message with two `RUBOUT' (interrupt,
2832 `control-C') characters,
2833 \*(UA will copy the partial letter to the file
2835 This option is set by default.
2836 .It Va searchheaders
2837 Expand message-list specifiers in the form `/x:y' to all messages
2838 containing the substring `y' in the header field `x'.
2839 The string search is case insensitive.
2840 .It Va sendcharsets-else-ttycharset
2841 \*(OP If this variable is set, but
2843 is not, then \*(UA acts as if
2845 had been set to the value of the variable
2847 In effect this combination passes through the message data in the
2848 character set of the current locale (given that
2850 hasn't been set manually), i.e., without converting it to the
2852 fallback character set.
2853 Thus, mail message text will be in `ISO-8859-1' encoding when send from
2854 within a `ISO-8859-1' locale, and in `UTF-8' encoding when send from
2855 within an `UTF-8' locale.
2856 If no character set conversion capabilities are available in \*(UA then
2857 the only supported character set is
2860 When sending a message wait until the MTA exits before accepting further
2862 If the MTA returns a non-zero exit status,
2863 the exit status of \*(ua will also be non-zero.
2865 Setting this option causes \*(UA to start at the last message instead of
2866 the first one when opening a mail folder.
2868 Causes \*(UA to use the sender's real name instead of the plain address
2869 in the header field summary and in message specifications.
2871 Causes the recipient of the message to be shown in the header summary
2872 if the message was sent by the user.
2873 .It Va skipemptybody
2874 If an outgoing message does not contain any text in its first or only
2876 do not send it but discard it silently (see also the command line option
2879 .It Va smime-force-encryption
2880 \*(OP Causes \*(UA to refuse sending unencrypted messages.
2882 \*(OP S/MIME sign outgoing messages with the user's private key and
2883 include the user's certificate as a MIME attachment.
2884 Signing a message enables a recipient to verify that the sender used
2885 a valid certificate,
2886 that the email addresses in the certificate match those in the message
2887 header and that the message content has not been altered.
2888 It does not change the message text,
2889 and people will be able to read the message as usual.
2893 .Va smime-sign-include-certs .
2894 .It Va smime-no-default-ca
2895 \*(OP Don't load default CA locations when verifying S/MIME signed
2897 .It Va smtp-use-starttls
2898 \*(OP Causes \*(UA to issue a `STARTTLS' command to make an SMTP session
2900 Not all servers support this command \(en because of common
2901 implementation defects it can't be automatically determined whether
2902 a server supports it or not.
2903 .It Va ssl-no-default-ca
2904 \*(OP Don't load default CA locations to verify SSL/TLS server
2907 \*(OP Accept SSLv2 connections.
2908 These are normally not allowed because this protocol version is insecure.
2909 .It Va keep-content-length
2910 When (editing messages and) writing MBOX mailbox files \*(UA can be told
2911 to keep the `Content-Length:' and `Lines:' header fields that some MUAs
2912 generate by setting this variable.
2913 Since \*(UA does neither use nor update these non-standardized header
2914 fields (which in itself shows one of their conceptual problems),
2915 stripping them should increase interoperability in between MUAs that
2916 work with with same mailbox files.
2917 Note that, if this is not set but
2918 .Va writebackedited ,
2919 as below, is, a possibly performed automatic stripping of these header
2920 fields already marks the message as being modified.
2922 Setting this option enables upward compatibility with \*(UA version 15.0
2923 in respect to which configuration options are available and how they are
2925 This manual uses \*(IN and \*(OU to refer to the new and the old way of
2926 doing things, respectively.
2928 Setting this option, also controllable via the command line option
2930 causes \*(UA to be more verbose, so that, e.g., certificate chains will
2931 be displayed on the users terminal.
2932 Setting this binary options twice increases the level of verbosity, in
2933 which case even details of the actual message delivery and protocol
2934 conversations are also shown.
2937 is sufficient to disable verbosity as such.
2938 .It Va writebackedited
2939 If this variable is set messages modified using the
2943 commands are written back to the current folder when it is quit;
2944 it is only honoured for writable folders in `mbox' format, though.
2945 Note that the editor will be pointed to the raw message content in that
2946 case, i.e., neither MIME decoding nor decryption will have been
2948 and proper RFC 4155 `From ' quoting of newly added or edited content is
2949 also left as an excercise to the user.
2953 .\" .Ss "Value options" {{{
2955 The value options include the following:
2956 .Bl -tag -width ".Va autoprint"
2958 A sequence of characters to print in the `attribute' column of a header
2960 each for one type of messages in the following order:
2961 new (N), unread but old (U), new but read (R), read and old (O), saved
2962 (S), preserved (P), mboxed (M), flagged (F), answered (A), draft (T),
2963 start of a collapsed thread (+), collapsed (\-), classified as spam ($).
2964 The default is `NUROSPMFAT+\-$',
2965 or `NU\ \ *HMFAT+\-$' if
2969 environment variable are set.
2971 Specifies a list of recipients to which a blind carbon copy of each
2972 outgoing message will be sent automatically.
2974 Specifies a list of recipients to which a carbon copy of each outgoing
2975 message will be sent automatically.
2977 Causes sorted mode (see the
2979 command) to be entered automatically with the value of this option as
2980 sorting method when a folder is opened.
2982 The value that should appear in the `charset=' parameter of
2983 `Content-Type:' MIME header fields when no character set conversion of
2984 the message data was performed.
2985 This defaults to `US-ASCII', and the chosen character set should be
2986 `US-ASCII' compatible.
2988 \*(OP The default 8 bit character set that is used as an implied last
2989 member of the variable
2991 Defaults to `UTF-8'.
2992 If no character set conversion capabilities are available in \*(UA then
2993 the only supported character set is
2995 Refer to the section
2996 .Sx "Character sets"
2997 for the complete picture of character set conversion in \*(UA.
2999 The default value for the
3003 \*(OP The colour specification for so-called `From_' lines.
3005 .Sx "Coloured message display"
3006 for the format of the value.
3007 .It Va colour-header
3008 \*(OP The colour specification for header lines.
3010 .Sx "Coloured message display"
3011 for the format of the value.
3012 .It Va colour-msginfo
3013 \*(OP The colour specification for the introductional message info line.
3015 .Sx "Coloured message display"
3016 for the format of the value.
3017 .It Va colour-pagers
3018 \*(OP A comma-separated list of
3020 s for which coloured message display can be used.
3021 Note that only a substring comparison is performed, meaning that the
3022 string `lesser' will match the string `less'.
3024 .Sx "Coloured message display"
3026 The default is set to the sole string `less'.
3027 .It Va colour-partinfo
3028 \*(OP The colour specification for MIME part info lines.
3030 .Sx "Coloured message display"
3031 for the format of the value.
3033 \*(OP A comma-separated list of
3035 inals for which coloured message display can be used.
3038 .Dl cons25,linux,rxvt,rxvt-unicode,\:screen,\:sun,\:vt100,\:vt220,\:\
3039 wsvt25,\:xterm,\:xterm-color
3040 .It Va colour-uheader
3041 \*(OP The colour specification for those header lines that have been
3043 .Va colour-user-headers
3046 .Sx "Coloured message display"
3047 for the format of the value.
3048 .It Va colour-user-headers
3049 A comma separated list of (case-insensitive) header names which should
3050 be colourized with the alternative
3053 The default value is `from,subject'.
3055 The valued option crt is used as a threshold to determine how long
3056 a message must be before
3061 is set without a value then the height of the terminal screen stored in
3062 the system is used to compute the threshold (see
3068 The name of the file to use for saving aborted messages.
3069 This defaults to `dead.letter' in the user's home directory.
3071 The date in a header summary is normally the date of the mailbox `From\ '
3072 line of the message.
3073 If this variable is set, then the date as given in the `Date:' field is
3074 used, converted to local time.
3075 It is possible to control the display of the date by assigning a value,
3078 function will be used to format the date accordingly.
3079 Please read your system manual for the available formats.
3080 Note that the `%n' format should not be used, because \*(UA doesn't
3081 take embedded newlines into account when calculating how many lines fit
3083 .It Va datefield-markout-older
3084 This option, when set in addition to
3086 modifies the display of messages that are not really current in a way
3087 that is rather comparable to the
3092 The interpretation of the value is identical to what has been described
3096 Pathname of the text editor to use in the
3101 A default editor is used if this value is not defined.
3103 Suggestion for the MIME encoding to use in outgoing text messages
3105 Valid values are the default `quoted-printable', `8bit' and `base64'.
3106 `8bit' may cause problems with when transferring mail messages over
3107 channels that are not ESMTP (RFC 1869) compliant.
3108 If there is no need to encode a message,
3109 `7bit' transfer mode is always used regardless of this variable.
3110 Binary data is always encoded as `base64'.
3112 If defined, the first character of this option
3113 gives the character to use in place of `~' to denote tilde escapes.
3115 The name of the directory to use for storing folders of messages.
3116 All folder names that begin with `+' refer to files below it.
3117 The same special conventions as documented for the
3119 command may be used when specifying a new value for
3121 but be aware that the expansion is fully performed immediately.
3122 E.g., if the expanded name refers to an IMAP account, all names that
3123 begin with `+' refer to IMAP mailboxes below the
3127 Note: some IMAP servers do not accept the creation of mailboxes in
3128 the hierarchy base, but require that they are created as subfolders of
3129 `INBOX' \(en with such servers a folder name of the form
3131 .Dl imaps://mylogin@imap.myisp.example/INBOX.
3133 should be used (the last character is the server's hierarchy delimiter).
3134 Folder names prefixed by `+' will then refer to folders below `INBOX',
3135 while folder names prefixed by `@' refer to folders below the hierarchy
3139 namespace command for a method to detect the appropriate prefix and
3142 When a folder is opened and this variable is set,
3143 the macro corresponding to the value of this variable is executed.
3144 The macro is also invoked when new mail arrives,
3145 but message lists for commands executed from the macro
3146 only include newly arrived messages then.
3147 .It Va folder-hook-fullname
3148 When a folder named `fullname' is opened,
3149 the macro corresponding to the value of this variable is executed.
3150 Unlike other folder specifications,
3151 the fully expanded name of a folder, without metacharacters,
3152 is used to avoid ambiguities.
3153 The macro specified with
3155 is not executed if this variable is effective for a folder
3158 ed from within the actually executed macro).
3160 The address (or a list of addresses) to put into the `From:' field of
3161 the message header, quoting RFC 5322:
3162 the author(s) of the message, that is, the mailbox(es) of the person(s)
3163 or system(s) responsible for the writing of the message.
3164 If replying to messages these addresses are handled as if they were in
3168 If the machine's hostname is not valid at the Internet (for example at
3169 a dialup machine) then either this variable or
3174 adds even more fine-tuning capabilities),
3178 contains more than one address,
3181 variable is required (according to the standard RFC 5322).
3183 The string to print before the text of a message with the
3187 .Va forward-as-attachment
3189 Defaults to `-------- Original Message --------' if unset.
3190 No heading is printed if it is set to the empty string.
3192 A format string to use for the header summary,
3196 A `%' character introduces a format specifier.
3197 It may be followed by a number indicating the field width.
3198 If the (possibly implicitly implied) field width is negative, the field
3199 is to be left-aligned.
3200 Valid format specifiers are:
3201 .Bl -tag -offset indent -width "%%"
3205 The date when the message was received.
3207 The indenting level in threaded mode.
3209 The address of the message sender.
3211 The message thread structure.
3212 (Note that this format doesn't support a field width.)
3214 The number of lines of the message.
3218 The number of octets (bytes) in the message.
3220 Message subject (if any).
3222 Message subject (if any) in double quotes.
3224 The position in threaded/sorted order.
3226 A `>' for the current message, otherwise ` '.
3228 A `<' for the current message, otherwise ` '.
3230 The spam score of the message, as has been classified via the command
3236 The default is `%>\&%a\&%m\ %-18f\ %16d\ %4l/%\-5o\ %i%-s',
3237 or `%>\&%a\&%m\ %20-f\ \ %16d\ %3l/%\-5o\ %i%-S' if
3242 .It Va headline-bidi
3243 Bidirectional text requires special treatment when displaying headers,
3244 because numbers (in dates or for file sizes etc.) will not affect the
3245 current text direction, in effect resulting in ugly line layouts when
3246 arabic or other right-to-left text is to be displayed.
3247 On the other hand only a minority of terminals is capable to correctly
3248 handle direction changes, so that user interaction is necessary for
3250 Note that extended host system support is required nonetheless, e.g.,
3251 detection of the terminal character set is one precondition;
3252 and this feature only works in an Unicode (i.e., UTF-8) locale.
3254 In general setting this variable will cause \*(UA to encapsulate text
3255 fields that may occur when printing
3257 with special Unicode control sequences;
3258 it is possible to fine-tune the terminal support level by assigning
3260 no value (or any value other than `1', `2' and `3') will make \*(UA
3261 assume that the terminal is capable to properly deal with Unicode
3262 version 6.3, in which case text is embedded in a pair of U+2068 (FIRST
3263 STRONG ISOLATE) and U+2069 (POP DIRECTIONAL ISOLATE) characters.
3264 In addition no space on the line is reserved for these characters.
3266 Weaker support is chosen by using the value `1' (Unicode 6.3, but
3267 reserve the room of two spaces for writing the control sequences onto
3269 The values `2' and `3' select Unicode 1.1 support (U+200E, LEFT-TO-RIGHT
3270 MARK); the latter again reserves room for two spaces in addition.
3272 Use this string as hostname when expanding local addresses instead of
3273 the value obtained from
3277 i.e., in `Message-ID:' and `From:' fields.
3280 transport is not used then it is normally the responsibility of the MTA
3281 to create these fields, \*(IN in conjunction with
3285 also influences the results;
3286 you should produce some test messages with the desired combination of
3293 \*(OP Sets the IMAP authentication method.
3294 Valid values are `login' for the usual password-based authentication
3296 `cram-md5', which is a password-based authentication that does not send
3297 the password over the network in clear text,
3298 and `gssapi' for GSS-API based authentication.
3299 .It Va imap-auth-USER@HOST
3300 Sets the IMAP authentication method for a specific account.
3302 \*(OP Enables caching of IMAP mailboxes.
3303 The value of this variable must point to a directory that is either
3304 existent or can be created by \*(UA.
3305 All contents of the cache can be deleted by \*(UA at any time;
3306 it is not safe to make assumptions about them.
3307 .It Va imap-keepalive
3308 \*(OP IMAP servers may close the connection after a period of
3309 inactivity; the standard requires this to be at least 30 minutes,
3310 but practical experience may vary.
3311 Setting this variable to a numeric `value' greater than 0 causes
3312 a `NOOP' command to be sent each `value' seconds if no other operation
3314 .It Va imap-list-depth
3315 \*(OP When retrieving the list of folders on an IMAP server, the
3317 command stops after it has reached a certain depth to avoid possible
3319 The value of this variable sets the maximum depth allowed.
3321 If the folder separator on the current IMAP server is a slash `/',
3322 this variable has no effect and the
3324 command does not descend to subfolders.
3326 String used by the `~m', `~M' and `~R' tilde escapes and by the
3328 option for indenting messages,
3329 in place of the normal tabulator character (`^I'), which is the default.
3330 Be sure to quote the value if it contains spaces or tabs.
3332 Pathname of the directory lister to use in the
3334 command when operating on local mailboxes.
3337 .It Va line-editor-cursor-right
3338 \*(OP If the builtin command line editor is used, actions which are
3339 based on rightwise movement may not work on some terminals.
3340 If you encounter such problems, set this variable to the terminal
3341 control sequence that is necessary to move the cursor one column to the
3343 The default is `\\033[C', which should work for most terminals.
3344 Less often occur `\\033OC' and `\\014'.
3345 Note that `ESCAPE' and other control character have to be written as
3346 shell-style escape sequences, e.g., `\\033' for `ESCAPE'.
3348 Is used as the user's mailbox, if set.
3349 Otherwise, a system-dependent default is used.
3350 Supports a logical subset of the special conventions that are documented
3357 The name of the mbox file.
3358 Supports a logical subset of the special conventions that are documented
3364 The fallback default is `mbox' in the user's home directory.
3365 .It Va mimetypes-load-control
3366 This option can be used to control which of the
3368 MIME type databases are loaded by \*(UA.
3369 If the letter `u' (or `U') is part of this options value, then the
3372 file will be loaded (if it exists);
3373 likewise the letter `s' (or `S') controls loading of the system wide
3374 .Pa /etc/mime.types .
3375 If this option is not set \*(UA will try to load both files instead.
3376 Incorporation of the MIME types that are compiled into \*(UA cannot be
3378 .It Va NAIL_EXTRA_RC
3379 The name of an optional startup file to be read after \*(ur.
3380 This variable is ignored if it is imported from the environment;
3381 it has an effect only if it is set in \*(UR or \*(ur to allow bypassing
3382 the configuration with, e.g., `MAILRC=/dev/null'.
3383 Use this file for commands that are not understood by other \*(UA
3386 A string to put at the beginning of each new message.
3387 The escape sequences `\et' (tabulator) and `\en' (newline) are understood.
3388 .It Va NAIL_HISTFILE
3389 \*(OP If a command line editor is available then this can be set to
3390 name the (expandable) path of the location of a permanent history file.
3391 .It Va NAIL_HISTSIZE
3392 \*(OP If a command line editor is available this value restricts the
3393 amount of history entries that are saved into a set and valid
3395 A value of less than 0 disables this feature;
3396 note that loading and incorporation of
3398 upon program startup can also be suppressed by doing this.
3399 An unset or invalid value, or 0, causes a default value to be used.
3400 Dependent on the available command line editor this will also define the
3401 number of history entries in memory;
3402 it is also editor-specific wether runtime updates of this value will be
3405 A string to put at the end of each new message.
3406 The escape sequences `\et' (tabulator) and `\en' (newline) are understood.
3408 If this variable has the value `maildir',
3409 newly created local folders will be in `maildir' format.
3411 Checks for new mail in the current folder each time the prompt is
3413 For IMAP mailboxes the server is then polled for new mail,
3414 which may result in delayed operation if the connection to the server is
3416 A `maildir' folder must be re-scanned to determine if new mail has
3419 If this variable is set to the special value `nopoll' an IMAP server is
3420 not actively asked for new mail,
3421 but new mail may still be detected and announced with any other IMAP
3422 command that is sent to the server.
3423 A `maildir' folder is not scanned, then.
3425 In either case the IMAP server may send notifications about messages
3426 that have been deleted on the server by another process or client.
3427 In this case, `Expunged X messages' is printed regardless of this
3429 and message numbers may have changed.
3431 The value to put into the `Organization:' field of the message header.
3433 Pathname of the program to use in the more command or when the
3436 The default paginator is
3439 \*(IN Sets a global fallback password, which is used in case none has
3440 been given in the protocol and account-specific URL and neither is there
3441 a matching `password-USER@HOST' nor a matching `password-HOST';
3442 as a last resort \*(UA will ask for a password on the user's terminal if
3443 the authentication method requires a password.
3444 Specifying passwords in a startup file is generally a security risk;
3445 the file should be readable by the invoking user only.
3446 .It Va password-HOST
3449 for accounts on a specific host.
3450 .It Va password-USER@HOST
3455 for a specific account.
3457 Set the password for `user' when connecting to `host'.
3458 If no such variable is defined for a host,
3459 the user will be asked for a password on standard input.
3460 Specifying passwords in a startup file is generally a security risk;
3461 the file should be readable by the invoking user only.
3462 .It Va pipe-content/subcontent
3463 When a MIME message part of `content/subcontent' type is displayed or
3465 its text is filtered through the value of this variable interpreted as
3468 The special value `@' can be used to force interpretation of the message
3469 part as plain text, e.g., `set pipe-application/pgp-signature=@' will
3470 henceforth treat signatures as plain text and display them "as is".
3472 Also, if a normal shell command is prefixed with `@', then the command
3473 will only be used to prepare the MIME message part if the message is
3474 displayed by itself, but not when multiple messages are displayed at
3477 Finally, if a normal shell command is prefixed with `@&', then, in
3478 addition to what has been described for the plain `@' shell command
3479 prefix, the command will be run asynchronously, i.e., without blocking
3480 \*(UA, which may be a handy way to display a, e.g., PDF file while also
3481 continuing to read the mail message.
3483 Special care must be taken when using such commands as mail viruses may
3484 be distributed by this method;
3485 if messages of type `application/x-sh' were filtered through the shell,
3487 a message sender could easily execute arbitrary code on the system \*(UA
3489 .It Va pop3-keepalive
3490 \*(OP POP3 servers close the connection after a period of inactivity;
3491 the standard requires this to be at least 10 minutes,
3492 but practical experience may vary.
3493 Setting this variable to a numeric `value' greater than 0 causes
3494 a `NOOP' command to be sent each `value' seconds if no other operation
3497 The string printed when a command is accepted.
3498 Prompting may be prevented by either setting this to the null string
3501 The same XSI escape sequences that are understood by the
3503 command may be used within
3506 In addition, the following \*(UA specific additional sequences are
3508 `\\&', which expands to `?' unless
3510 is set, in which case it expands to `&';
3511 note that "\\& " is the default value for
3513 `\\?', which will expand to `1' if the last command failed, and to `0'
3515 `\\$', which will expand to the name of the currently active
3517 if any, and to the empty string otherwise,
3518 and `\\@', which will expand to the name of the currently active mailbox.
3519 (Note that the prompt buffer is size-limited, excess is cut off.)
3525 to encapsulate the expansions of the `\\$' and `\\@' escape sequences as
3526 necessary to correctly display bidirectional text, this is not true for
3527 the final string that makes up
3529 as such, i.e., real BIDI handling is not (yet) supported.
3531 When a newer version of the
3533 .Sx "Command line editor"
3534 is used, any escape sequence must itself be encapsulated with another
3535 escape character for usage with the
3537 mechanism: \*(UA configures the control character `\\01' for this.
3539 If set, \*(UA starts a replying message with the original message
3540 prefixed by the value of the variable
3542 Normally, a heading consisting of `Fromheaderfield wrote:' is printed
3543 before the quotation.
3544 If the string `noheading' is assigned to the
3546 variable, this heading is omitted.
3547 If the string `headers' is assigned, the headers selected by the
3548 .Ic ignore Ns / Ns Ic retain
3549 commands are printed above the message body,
3552 acts like an automatic `~m' tilde escape command, then.
3553 If the string `allheaders' is assigned, all headers are printed above
3554 the message body and all MIME parts are included,
3557 act like an automatic `~M' command.
3559 .Va quote-as-attachment .
3561 \*(OP Can be set in addition to
3563 Setting this turns on a more fancy quotation algorithm in that leading
3564 quotation characters are compressed and overlong lines are folded.
3566 can be set to either one or two (space separated) numeric values,
3567 which are interpreted as the maximum (goal) and the minimum line length,
3568 respectively, in a spirit rather equal to the
3570 program, but line-, not paragraph-based.
3571 If not set explicitly the minimum will reflect the goal algorithmically.
3572 The goal can't be smaller than the length of
3574 plus some additional pad.
3575 Necessary adjustments take place silently.
3577 If defined, gives the pathname of the folder used to record all outgoing
3579 If not defined, then outgoing mail is not saved.
3580 When saving to this folder fails the message is not sent,
3581 but instead saved to
3584 A list of addresses to put into the `Reply-To:' field of the message
3586 Members of this list are handled as if they were in the
3590 When \*(UA initially prints the message headers it determines the number
3591 to print by looking at the speed of the terminal.
3592 The faster the terminal, the more it prints.
3593 This option overrides this calculation and specifies how many message
3594 headers are printed.
3595 This number is also used for scrolling with the
3599 \*(OP A comma-separated list of character set names that can be used in
3600 outgoing Internet mail.
3601 The value of the variable
3603 is automatically appended to this list of character-sets.
3604 If no character set conversion capabilities are compiled into \*(UA then
3605 the only supported charset is
3608 .Va sendcharsets-else-ttycharset
3609 and refer to the section
3610 .Sx "Character sets"
3611 for the complete picture of character set conversion in \*(UA.
3613 An address that is put into the `Sender:' field of outgoing messages,
3614 quoting RFC 5322: the mailbox of the agent responsible for the actual
3615 transmission of the message.
3616 This field should normally not be used unless the `From:' field contains
3617 more than one address, on which case it is required.
3620 address is handled as if it were in the
3624 To use an alternate mail delivery system,
3625 set this option to the full pathname of the program to use.
3626 It may be necessary to set
3627 .Va sendmail-progname
3629 .It Va sendmail-progname
3630 Many systems use a so-called
3632 environment to ensure compatibility with
3634 This works by inspecting the name that was used to invoke the mail
3636 If this variable is set then the mailwrapper (the program that is
3637 actually executed when calling `sendmail') will treat its contents as
3639 The default is `sendmail'.
3641 Pathname of the shell to use in the
3643 command and the `~!' tilde escape.
3644 A default shell is used if this option is not defined.
3646 A string for use with the `~A' tilde escape.
3648 A string for use with the `~a' tilde escape.
3650 Must correspond to the name of a readable file if set.
3651 The file's content is then appended to each singlepart message
3652 and to the first part of each multipart message.
3653 Be warned that there is no possibility to edit the signature for an
3656 \*(OP Specifies a directory with CA certificates in PEM (Privacy
3657 Enhanced Mail) format for verification of S/MIME signed messages.
3658 .It Va smime-ca-file
3659 \*(OP Specifies a file with CA certificates in PEM format for
3660 verification of S/MIME signed messages.
3661 .It Va smime-cipher-USER@HOST
3662 \*(OP Specifies a cipher to use when generating S/MIME encrypted
3663 messages for the specified account.
3664 RFC 5751 mandates a default of `aes-128' (AES-128 CBC).
3666 The actually available cipher algorithms depend on the cryptographic
3667 library that \*(UA uses; possible values are, in decreasing cipher
3669 `aes-256' (AES-256 CBC), `aes-192' (AES-192 CBC), `aes-128' (AES-128 CBC),
3670 `des3' (DES EDE3 CBC, 168 bits; default if `aes-128' isn't available)
3671 and `des' (DES CBC, 56 bits).
3673 The following ciphers have been obsoleted and are no longer mentioned by
3674 the S/MIME specification (RFC 5751), but may be selected if available:
3675 `rc2-64' (RC2 CBC, 64 bits) and `rc2-40' (RC2 CBC, 40 bits).
3676 .It Va smime-crl-file
3677 \*(OP Specifies a file that contains a CRL in PEM format to use when
3678 verifying S/MIME messages.
3679 .It Va smime-crl-dir
3680 \*(OP Specifies a directory that contains files with CRLs in PEM format
3681 to use when verifying S/MIME messages.
3682 .It Va smime-encrypt-USER@HOST
3683 \*(OP If this variable is set, messages send to the given receiver are
3684 encrypted before sending.
3685 The value of the variable must be set to the name of a file that
3686 contains a certificate in PEM format.
3688 If a message is sent to multiple recipients,
3689 each of them for whom a corresponding variable is set will receive an
3690 individually encrypted message;
3691 other recipients will continue to receive the message in plain text
3693 .Va smime-force-encryption
3695 It is recommended to sign encrypted messages, i.e., to also set the
3698 .It Va smime-sign-cert
3699 \*(OP Points to a file in PEM format.
3700 For the purpose of signing and decryption this file needs to contain the
3701 user's private key as well as his certificate.
3703 For the purpose of encryption the recipient's public encryption key
3704 (certificate) is expected; the command
3706 can be used to save certificates of signed messages (the section
3707 .Sx "Signed and encrypted messages with S/MIME"
3708 gives some details).
3709 This mode of operation is usually driven via
3710 .Va smime-sign-cert-USER@HOST ,
3712 .It Va smime-sign-cert-USER@HOST
3715 for a specific account.
3716 For message signing `USER@HOST' is always derived from the value of
3718 (or, if that contains multiple addresses,
3722 When decrypting messages the account is derived from the recipient
3723 fields (`To:' and `Cc:') of the message, which are searched for
3724 addresses for which such a variable is set.
3725 \*(UA always uses the first address that matches,
3726 so if the same message is sent to more than one of the user's addresses
3727 using different encryption keys, decryption might fail.
3728 .It Va smime-sign-include-certs
3729 \*(OP If used, this is supposed to a consist of a comma-separated list
3730 of files, each of which containing a single certificate in PEM format to
3731 be included in the S/MIME message in addition to the
3734 This is most useful for long certificate chains if it is desired to aid
3735 the receiving party's verification process.
3736 Note that top level certificates may also be included in the chain but
3737 don't play a role for verification.
3741 .Va smime-sign-cert-USER@HOST .
3742 .It Va smime-sign-include-certs-USER@HOST
3744 .Va smime-sign-include-certs
3745 for a specific account.
3747 \*(OP Normally \*(UA invokes the program defined via
3749 to transfer messages.
3752 variable will instead cause `SMTP' network connections be made to the
3753 server specified therein in order to directly submit the message.
3754 \*(UA knows about three different "SMTP protocols":
3755 .Bl -bullet -offset indent
3757 The plain `SMTP' protocol (RFC 5321) that normally lives on the
3758 server port 25 and requires setting of the
3759 .Va smtp-use-starttls
3760 variable as above to enter a SSL/TLS encrypted session state.
3761 Assign a value like \*(IN `[smtp://][user[:password]@]server[:port]'
3762 (\*(OU `[smtp://]server[:port]')
3763 to choose this protocol.
3765 Then the so-called `SMTPS' which is supposed to live on server port 465
3766 and is automatically SSL/TLS secured.
3767 Unfortunately it never became a standardized protocol and may thus not
3768 be supported by your hosts network service database
3769 \(en in fact the port number has already been reassigned to other
3772 `SMTPS' is nonetheless a commonly offered "protocol" and thus can be
3773 chosen by assigning a value like \*(IN
3774 `smtps://[user[:password]@]server[:port]'
3775 (\*(OU `smtps://server[:port]');
3776 due to the mentioned problems it is usually necessary to explicitly
3777 specify the port as `:465', however.
3779 Finally there is the `SUBMISSION' protocol (RFC 6409), which usually
3780 lives on server port 587 and is practically identically to the `SMTP'
3781 protocol from \*(UAs point of view beside that; it requires setting the
3782 .Va smtp-use-starttls
3783 variable to enter a SSL/TLS secured session state.
3784 Assign a value like \*(IN `submission://[user[:password]@]server[:port]'
3785 (\*(OU `submission://server[:port]').
3788 \*(IN If `user' or `password' contain special characters, in particular
3789 whitespace, `/', `:' or `%', they must be specified in URL notation
3792 may be helpful for preparation).
3794 The SMTP transfer is executed in a child process, which runs
3795 asynchronously unless either the
3800 If it receives a TERM signal, it will abort and save the message to
3803 \*(OP Sets the SMTP authentication method.
3804 Possible values are `none' (the default), `plain', `login'
3805 as well as the \*(OPal methods `cram-md5' and `gssapi'.
3806 The `none' method doesn't need any user credentials,
3807 `gssapi' requires a user name
3808 and all other methods require a user name and a password.
3815 .Va smtp-auth-password
3817 .Va smtp-auth-user Ns
3819 .It Va smtp-auth-HOST
3822 for SMTP accounts on a specific host.
3823 .It Va smtp-auth-USER@HOST
3826 for a specific account.
3827 (\*(OU For specific values of sender addresses, dependend upon the variable
3830 .It Va smtp-auth-password
3831 \*(OP \*(OU Sets the global fallback password for SMTP authentication.
3832 If the authentication method requires a password, but neither
3833 .Va smtp-auth-password
3835 .Va smtp-auth-password-USER@HOST
3837 \*(UA will ask for a password on the user's terminal.
3838 .It Va smtp-auth-password-USER@HOST
3840 .Va smtp-auth-password
3841 for specific values of sender addresses, dependent upon the variable
3843 .It Va smtp-auth-user
3844 \*(OP \*(OU Sets the global fallback user name for SMTP authentication.
3845 If the authentication method requires a user name, but neither
3848 .Va smtp-auth-user-USER@HOST
3850 \*(UA will ask for a user name on the user's terminal.
3851 .It Va smtp-auth-user-USER@HOST
3854 for specific values of sender addresses, dependent upon the variable
3856 .It Va smtp-hostname
3857 \*(IN Normally \*(UA uses the variable
3859 to derive the necessary `USER@HOST' information to issue a
3860 `MAIL FROM:<>' SMTP command.
3863 can be used to use the `USER' from the SMTP account
3868 and the `HOST' from the content of this variable
3869 (or, if that is the empty string,
3871 or the local hostname as a last resort).
3872 Setting this variable also influences the generated `Message-Id:'.
3874 \*(OP The path to the spam detector.
3875 Note that the path is not expanded, but used "as is".
3876 A fallback path will have been compiled into the \*(UA binary if the
3878 executable had been found during compilation.
3880 \*(OP Can be used to specify the host on which
3882 listens for connections; if not set, defaults to `localhost'.
3884 \*(OP Spam detectors like
3886 decline to work with messages which exceed a specific size;
3887 if this variable is set then \*(UA won't even try to pass messages which
3888 exceed the given limit.
3889 The default is 420000 bytes.
3891 \*(OP Can be used to explicitly specify the port on which
3893 listens for connections.
3895 \*(OP If the spam detector listens on a path-based UNIX domain socket,
3896 then setting this variable to the fully qualified path will force its
3897 usage for communication.
3899 \*(OP This can be used to support multiple, per-used configuration files
3900 of the spam detector.
3901 Note that \*(UA doesn't automatically set this to reflect a possibly set
3905 \*(OP Specifies a directory with CA certificates in PEM (Pricacy
3906 Enhanced Mail) for verification of of SSL/TLS server certificates.
3908 .Xr SSL_CTX_load_verify_locations 3
3909 for more information.
3911 \*(OP Specifies a file with CA certificates in PEM format for
3912 verification of SSL/TLS server certificates.
3914 .Xr SSL_CTX_load_verify_locations 3
3915 for more information.
3917 \*(OP Sets the file name for a SSL/TLS client certificate required by
3919 .It Va ssl-cert-USER@HOST
3920 Sets an account-specific file name for a SSL/TLS client certificate
3921 required by some servers.
3924 for the specified account.
3925 .It Va ssl-cipher-list
3926 \*(OP Specifies a list of ciphers for SSL/TLS connections.
3929 for more information.
3931 \*(OP Specifies a file that contains a CRL in PEM format to use when
3932 verifying SSL/TLS server certificates.
3934 \*(OP Specifies a directory that contains files with CRLs in PEM format
3935 to use when verifying SSL/TLS server certificates.
3937 \*(OP Sets the file name for the private key of a SSL/TLS client
3939 If unset, the name of the certificate file is used.
3940 The file is expected to be in PEM format.
3941 .It Va ssl-key-USER@HOST
3942 Sets an account-specific file name for the private key of a SSL/TLS
3946 for the specified account.
3948 \*(OP Selects the used TLS/SSL protocol version.
3949 The actually available protocol versions depend on the TLS/SSL
3950 library that \*(UA uses; possible values are, from newest to oldest:
3951 `tls1.2', `tls1.1', `tls1', `ssl3' and `ssl2'.
3955 to any of these values will fixate the used protocol, which means that
3956 connections will fail if the server doesn't support it.
3957 The value `auto', which is the default, chooses a compatibility method
3958 that automatically uses the newest protocol version that the server
3959 is capable to understand.
3961 It has to be noted that `auto' is used as a fallback method if
3962 the actual setting of
3964 isn't supported by the used TLS/SSL library \(em in this case an error
3965 message will be printed first, however.
3966 .It Va ssl-method-USER@HOST
3969 for a specific account.
3971 \*(OP Gives the pathname to an entropy daemon socket, see
3973 Note that (as of 2014) not all OpenSSL installations include this
3975 .It Va ssl-rand-file
3976 \*(OP Gives the pathname to a file with entropy data, see
3977 .Xr RAND_load_file 3 .
3978 If the file is a regular file writable by the invoking user,
3979 new data is written to it after it has been loaded.
3981 \*(OP Sets the action to be performed if an error occurs during SSL/TLS
3982 server certificate validation.
3984 `strict' (fail and close connection immediately),
3985 `ask' (ask whether to continue on standard input),
3986 `warn' (print a warning and continue),
3987 `ignore' (do not perform validation).
3988 The default is `ask'.
3989 .It Va ssl-verify-USER@HOST
3992 for a specific account.
3994 If only set without an assigned value, then this option inhibits the
3995 generation of the `Message-Id:' and `User-Agent:' header fields that
3996 include obvious references to \*(UA.
3997 There are two pitfalls associated with this:
3998 First, the message id of outgoing messages is not known anymore.
3999 Second, an expert may still use the remaining information in the header
4000 to track down the originating mail user agent.
4001 If set to the value `noagent', then the mentioned `Message-Id:'
4002 suppression doesn't occur.
4004 If defined, gives the number of lines of a message to be printed out
4005 with the top command;
4006 normally, the first five lines are printed.
4008 The character set of the terminal \*(UA operates on,
4009 and the one and only supported character set that \*(UA can use if no
4010 character set conversion capabilities have been compiled into it,
4011 in which case it defaults to `ISO-8859-1' unless it can deduce a value
4012 from the `LC_CTYPE' locale environment.
4013 Refer to the section
4014 .Sx "Character sets"
4015 for the complete picture about character sets.
4017 \*(IN Sets a global fallback user name, which is used in case none has
4018 been given in the protocol and account-specific URL and there is also
4021 This variable defaults to the value of
4026 for a specific host.
4028 Pathname of the text editor to use in the
4030 command and `~v' tilde escape.
4034 .\" .Sh ENVIRONMENT {{{
4036 Besides the variables described above,
4037 \*(UA uses the following environment variables:
4038 .Bl -tag -width ".It Va MAILRC"
4040 The user's preferred width in column positions for the terminal screen
4041 or window (only used during startup).
4043 The user's home directory.
4044 .It Va LANG , Va LC_ALL , Va LC_COLLATE , Va LC_CTYPE , Va LC_MESSAGES
4048 The user's preferred number of lines on a page or the vertical screen or
4049 window size in lines (only used during startup).
4051 Is used as a startup file instead of \*(ur if set.
4052 When \*(UA scripts are invoked on behalf of other users,
4053 this variable should be set to
4055 to avoid side-effects from reading their configuration files.
4057 If this variable is set and
4059 is not, it is treated as a startup configuration file and read.
4060 .It Va NAIL_NO_SYSTEM_RC
4061 If this variable is set then reading of \*(UR at startup is inhibited,
4062 i.e., the same effect is achieved as if \*(UA had been started up with
4066 Changes the letters printed in the first column of a header summary.
4068 \*(OP The terminal type for which output is to be prepared.
4070 Used as directory for temporary files instead of
4074 Can be used to force identification as
4076 i.e., identical to the
4078 command line option.
4084 .Bl -tag -width ".It Pa /etc/mime.types"
4086 File giving initial commands.
4088 System wide initialization file.
4089 .It Pa ~/.mime.types
4090 Personal MIME types.
4091 .It Pa /etc/mime.types
4092 System wide MIME types.
4096 .\" .Sh EXAMPLES {{{
4099 .\" .Ss "Getting started" {{{
4100 .Ss "Getting started"
4101 The \*(UA command has two distinct usages, according to whether one
4102 wants to send or receive mail.
4103 Sending mail is simple: to send a message to a user whose email address
4104 is, say, `<bill@host.example>', use the shell command:
4106 .Dl $ \*(ua bill@host.example
4108 then type your message.
4109 \*(UA will prompt you for a message `Subject:' first;
4110 after that, lines typed by you form the body of the message.
4111 When you reach the end of the message,
4112 type an EOT (`control\-D') at the beginning of a line,
4113 which will cause \*(UA to echo `EOT' and return you to the shell.
4115 If, while you are composing the message you decide that you do not wish
4116 to send it after all, you can abort the letter by typing two `RUBOUT'
4117 (interrupt, `control-C') characters.
4118 Typing a single `RUBOUT' causes \*(UA to print
4119 .Ns ` Ns Li (Interrupt -- one more to kill letter) Ns '.
4120 Typing a second `RUBOUT' causes \*(UA to save your partial letter on the
4123 and abort the letter.
4124 Once you have sent mail to someone, there is no way to undo the act, so
4127 If you want to send the same message to several other people,
4128 you can list their email addresses on the command line.
4129 .Bd -literal -offset indent
4130 $ \*(ua sam@workstation.example bob@server.example
4132 Tuition fees are due next Friday. Don't forget!
4138 will sendout to `<sam@workstation.example>' and `<bob@server.example>'.
4139 To read your mail, simply type
4143 \*(UA will respond by typing its version number and date and then
4144 listing the messages you have waiting.
4145 Then it will type a prompt and await your command.
4146 The messages are assigned numbers starting with 1 \(en you refer to the
4147 messages with these numbers.
4148 \*(UA keeps track of which messages are `new' (have been sent since you
4149 last read your mail) and `read' (have been read by you).
4150 New messages have an `N' next to them in the header listing and old,
4151 but unread messages have a `U' next to them.
4152 \*(UA keeps track of new/old and read/unread messages by putting a
4153 header field called `Status' into your messages.
4155 To look at a specific message, use the
4157 command, which may be abbreviated to simply `t'.
4158 For example, if you had the following messages:
4159 .Bd -literal -offset indent
4160 O 1 drfoo@myhost.example Wed Sep 1 19:52 5/421 "Fees"
4161 O 2 sam@friends.example Thu Sep 2 00:08 30/895
4164 you could examine the first message by giving the command:
4168 which might cause \*(UA to respond with, for example:
4169 .Bd -literal -offset indent
4170 [-- Message 1 -- 5 lines, 421 bytes --]:
4171 From drfoo@myhost.example Wed Sep 1 19:52:25 2004
4175 Tuition fees are due next Wednesday. Don't forget!
4178 Many \*(UA commands that operate on messages take a message number as an
4179 argument, just as the shown
4182 For these commands, there is a notion of a current message.
4183 When you enter the \*(UA program,
4184 the current message is initially the first (or the first recent) one.
4185 Thus, you can often omit the message number and use, for example, `t` to
4186 type the current message.
4187 As a further shorthand, you can type a message by simply giving its
4188 message number \(en hence `1` would type the first message.
4190 Frequently, it is useful to read the messages in your mailbox in order,
4192 You can read the next message in \*(UA by simply typing a newline.
4193 As a special case, you can type a newline as your first command to
4194 \*(UA to type the first message.
4196 If, after typing a message, you wish to immediately send a reply,
4197 you can do so with the command
4201 takes a message number as an argument.
4202 \*(UA then begins a message addressed to the user who sent you the
4203 message and let you type in your letter in reply, followed by
4204 a `<control-D>' at the beginning of a line, as before.
4206 Note that \*(UA copies the subject header from the original message.
4207 This is useful in that correspondence about a particular matter will
4208 tend to retain the same subject heading, making it easy to recognize.
4209 If there are other header fields in the message, like `Cc:',
4210 the information found will also be used.
4212 Sometimes you will receive a message that has been sent to several
4213 people and wish to reply only to the person who sent it.
4215 (with a capital `R') replies to a message, but sends a copy to the
4218 If you wish, while reading your mail, to send a message to someone,
4219 but not as a reply to one of your messages, you can send the message
4222 command, which takes as arguments the names of the recipients you wish
4224 For example, to send a message to `<frank@machine.example>':
4226 .Dl mail frank@machine.example
4228 To delete a message from the mail folder, you can use the command
4230 In addition to not saving deleted messages,
4231 \*(UA will not let you type them, either.
4232 The effect is to make the message disappear altogether, along with its
4235 Many features of \*(UA can be tailored to your liking with the
4237 command; it has two forms, depending on whether you are setting
4238 a `binary' or a `valued' option.
4239 Binary options are either on or off \(en for example, the
4241 option informs \*(UA that each time you send a message, you want it to
4242 prompt you for a `Cc:' header to be included in the message.
4245 option, you would type
4249 Valued options are values which \*(UA uses to adapt to your tastes.
4252 option tells \*(UA where to save messages sent by you,
4253 and is specified by, e.g.,
4257 Note that no spaces are allowed in `set record=Sent'.
4259 \*(UA includes a simple facility for maintaining groups of messages
4260 together in folders.
4261 To use the folder facility, you must tell \*(UA where you wish to keep
4263 Each folder of messages will be a single file.
4264 For convenience, all of your folders are kept in a single directory of
4266 To tell \*(UA where your folder directory is, put a line of the form
4268 .Dl set folder=letters
4271 If, as in the example above, your folder directory does not begin with
4272 a `/', \*(UA will assume that your folder directory is to be found
4273 starting from your home directory.
4275 Anywhere a file name is expected, you can use a folder name, preceded
4277 For example, to put a message into a folder with the
4279 command, you can use:
4283 to save the current message in the `classwork' folder.
4284 If the `classwork' folder does not yet exist, it will be created.
4285 Note that messages which are saved with the
4287 command are automatically removed from your system mailbox.
4289 In order to make a copy of a message in a folder without causing
4290 that message to be removed from your system mailbox, use the
4292 command, which is identical in all other respects to the
4299 can be used to direct \*(UA to the contents of a different folder.
4302 .Dl folder +classwork
4304 directs \*(UA to read the contents of the `classwork' folder.
4305 All of the commands that you can use on your system mailbox are also
4306 applicable to folders, including
4311 To inquire which folder you are currently editing, use `folder' without
4313 And to list your current set of folders, use the
4319 command is available to print out a brief summary of the most important
4322 While typing in a message to be sent to others it is often useful to be
4323 able to invoke the text editor on the partial message, print the
4324 message, execute a shell command, or do some other auxiliary function.
4325 \*(UA provides these capabilities through `tilde escapes',
4326 which consist of a tilde (`~') at the beginning of a line, followed by
4327 a single character which indicates the function to be performed.
4328 For example, to print the text of the message so far, use:
4332 which will print a line of dashes, the recipients of your message, and
4333 the text of the message so far.
4334 A list of the most important tilde escapes is available with `~?'.
4337 .\" .Ss "IMAP or POP3 client setup" {{{
4338 .Ss "IMAP or POP3 client setup"
4339 \*(OP First you need the following data from your ISP:
4340 the host name of the IMAP or POP3 server,
4341 user name and password for this server,
4342 and a notice whether the server uses SSL/TLS encryption.
4343 Assuming the SSL/TLS secured host name of your IMAP account is
4344 `server.myisp.example' and your user name for that server is `mylogin',
4345 you could refer to this account using the
4349 command line option with
4351 .Dl imaps://mylogin@server.myisp.example
4353 (This string is not necessarily the same as your Internet mail address.)
4354 Even if the server does not accept IMAPS or POP3S connections,
4355 it is possible that it supports the `STARTTLS' method of upgrading
4356 already connected, but not yet authenticated sessions to use SSL/TLS
4358 The only reliable method to see if this works is to try it; enter one of
4360 .Dl set imap-use-starttls
4361 .Dl set pop3-use-starttls
4363 before you initiate the connection, dependent on the actual protocol.
4365 As you probably want messages to be deleted from this account
4366 after saving them, prefix it with `%:'.
4369 command can be used to avoid typing that many characters every time you
4372 .Dl shortcut myisp %:imaps://mylogin@server.myisp.example
4374 You might want to put this string into a startup file.
4376 is one of those commands that are specific to \*(UA and will thus
4377 confuse other implementations of POSIX
4379 so it should possibly not be placed in \*(ur.
4382 .Dl set NAIL_EXTRA_RC=.\*(uarc
4384 in \*(ur and create a file
4386 containing all the commands that are specific to \*(UA.
4387 You can then access your remote mailbox by invoking
4391 on the command line, or by executing
4396 If you want to use more than one IMAP mailbox on a server,
4397 or if you want to use the IMAP server for mail storage too, the
4399 command (which is also \*(UA-specific) is possibly more appropriate.
4400 You can put the following in
4402 .Bd -literal -offset indent
4404 set folder=imaps://mylogin@server.myisp.example
4405 set record=+Sent MBOX=+mbox outfolder
4409 and can then access incoming mail for this account by invoking
4410 `\*(ua \-A myisp' on the command line or by executing `ac myisp' within
4412 After that, a command like `copy 1 +otherfolder' will refer to
4413 `otherfolder' on the IMAP server.
4414 In particular, `fi&' will change to the `mbox' folder,
4415 and `fi+Sent' will show your recorded sent mail,
4416 with both folders located on the IMAP server.
4418 \*(UA will ask you for a password string each time you connect to
4420 If you can reasonably trust the security of your workstation,
4421 you can give this password in the startup file as
4423 .Dl set password-mylogin@server.myisp.example="SECRET"
4425 You should change the permissions of this file to 0600, see
4428 \*(UA supports different authentication methods for both IMAP and POP3.
4429 If Kerberos is used at your location,
4430 you can try to activate (the optional) GSS-API based authentication via
4432 .Dl set imap-auth=gssapi
4434 The advantage of this method is that \*(UA doesn't need to know your
4435 password at all, nor does it have to send sensitive data over the network.
4436 If that isn't possible, try to use authentication methods that at least
4437 avoid sending the password in clear over the wire, which is especially
4438 important if SSL/TLS cannot be used, e.g.,
4440 .Dl set imap-auth=cram-md5
4442 For POP3 \*(UA will try to use the `APOP' mechanism automatically unless
4443 explicitly disabled.
4444 If the server does not offer any such authentication methods,
4445 conventional user/password based authentication must be used.
4446 It is sometimes helpful, especially when setting up an account or when
4447 there are authentification problems, to enable verbosity by setting the
4449 option \(en \*(UA will display all data sent to the server in clear text
4450 on the screen when this option is set.
4451 (Because this may also include passwords you should take care that no
4452 unauthorized person can look at your terminal when this option is set.)
4454 If you regularly use the same workstation to access IMAP accounts,
4455 you can greatly enhance performance by enabling local caching of IMAP
4457 For any message that has been fully or partially fetched from the server,
4458 a local copy is made and is used when the message is accessed again,
4459 so most data is transferred over the network once only.
4460 To enable the IMAP cache, select a local directory name and put
4462 .Dl set imap-cache=~/localdirectory
4464 in the (\*(UA-specific) startup file.
4465 All files within that directory can be overwritten or deleted by \*(UA
4467 so you should not use the directory to store other information.
4469 Once the cache contains some messages,
4470 it is not strictly necessary anymore to open a connection to the IMAP
4471 server to access them.
4472 When \*(UA is invoked with the option
4477 only cached data is used for any folder you open.
4478 Messages that have not yet been completely cached are not available
4479 then, but all other messages can be handled as usual.
4480 Changes made to IMAP mailboxes in
4482 mode are committed to the IMAP server next time it is being connected to.
4483 Synchronizing the local status with the status on the server is thus
4484 partially within your responsibility;
4485 if you forget to initiate a connection to the server again before you
4486 leave your location,
4487 changes made on one workstation are not available on others.
4488 Also if you alter IMAP mailboxes from a workstation while uncommitted
4489 changes are still pending on another,
4490 the latter data may become invalid.
4491 The same might also happen because of internal server status changes.
4492 You should thus carefully evaluate this feature in your environment
4493 before you rely on it.
4495 Many servers will close the connection after a short period of
4496 inactivity \(en use one of
4498 .Dl set pop3-keepalive=30
4499 .Dl set imap-keepalive=240
4501 to send a keepalive message each 30 seconds for POP3,
4502 or each 4 minutes for IMAP.
4504 If you encounter problems connecting to a SSL/TLS server,
4509 variables (see the OpenSSL FAQ for more information) or specify the
4510 protocol version with
4512 Contact your ISP if you need a client certificate or if verification of
4513 the server certificate fails.
4514 If the failed certificate is indeed valid,
4515 fetch its CA certificate by executing the shell command
4517 .Dl $ </dev/null openssl s_client \-showcerts \-connect \e
4518 .Dl \ \ \ \ \ \ server.myisp.example:imaps 2>&1 | tee log.txt
4522 ) and put it into the file specified with
4524 The data you need is located at the end of the certificate chain
4525 within (and including) the `BEGIN CERTIFICATE'
4526 and `END CERTIFICATE' lines.
4527 Note that the example above is \fBinsecure\fR!
4528 One should use the `-verify' and `-CAfile' options of
4530 to be "on the safe side" regarding the fetched certificates.
4533 .\" .Ss "Reading HTML mail" {{{
4534 .Ss "Reading HTML mail"
4539 utility or another command-line web browser that can write plain text to
4542 .Dl set pipe-text/html="elinks -force-html -dump 1"
4543 .Dl set pipe-text/html="lynx -stdin -dump -force_html"
4545 will cause HTML message parts to be converted into a more friendly form.
4548 .\" .Ss "Viewing PDF attachments" {{{
4549 .Ss "Viewing PDF attachments"
4550 Most PDF viewers do not accept input directly from a pipe.
4551 It is thus necessary to store the attachment in a temporary file first:
4553 .Dl set pipe-application/pdf="@&cat >/tmp/\*(ua$$.pdf; \e
4554 .Dl \ \ \ \ \ \ acroread /tmp/\*(ua$$.pdf; rm /tmp/\*(ua$$.pdf"
4556 Note that security defects are discovered in PDF viewers from time to
4558 Automatical command execution like this can compromise your system
4560 in particular if you stay not always informed about such issues.
4563 .\" .Ss "Signed and encrypted messages with S/MIME" {{{
4564 .Ss "Signed and encrypted messages with S/MIME"
4565 \*(OP S/MIME provides two central mechanisms:
4566 message signing and message encryption.
4567 A signed message contains some data in addition to the regular text.
4568 The data can be used to verify that the message was sent using a valid
4569 certificate, that the sender's address in the message header matches
4570 that in the certificate, and that the message text has not been altered.
4571 Signing a message does not change its regular text;
4572 it can be read regardless of whether the recipient's software is able to
4574 It is thus usually possible to sign all outgoing messages if so desired.
4575 Encryption, in contrast, makes the message text invisible for all people
4576 except those who have access to the secret decryption key.
4577 To encrypt a message, the specific recipient's public encryption key
4579 It is thus not possible to send encrypted mail to people unless their
4580 key has been retrieved from either previous communication or public key
4582 A message should always be signed before it is encrypted.
4583 Otherwise, it is still possible that the encrypted message text is
4586 A central concept to S/MIME is that of the certification authority (CA).
4587 A CA is a trusted institution that issues certificates.
4588 For each of these certificates it can be verified that it really
4589 originates from the CA, provided that the CA's own certificate is
4591 A set of CA certificates is usually delivered with OpenSSL and installed
4593 If you trust the source of your OpenSSL software installation,
4594 this offers reasonable security for S/MIME on the Internet.
4595 In general, a certificate cannot be more secure than the method its CA
4596 certificate has been retrieved with, though.
4597 Thus if you download a CA certificate from the Internet,
4598 you can only trust the messages you verify using that certificate as
4599 much as you trust the download process.
4601 The first thing you need for participating in S/MIME message exchange is
4602 your personal certificate, including a private key.
4603 The certificate contains public information, in particular your name and
4604 your email address, and the public key that is used by others to encrypt
4606 and to verify signed messages they supposedly received from you.
4607 The certificate is included in each signed message you send.
4608 The private key must be kept secret.
4609 It is used to decrypt messages that were previously encrypted with your
4610 public key, and to sign messages.
4612 For personal use it is recommended that you get a S/MIME certificate
4613 from one of the major CAs on the Internet using your WWW browser.
4614 (Many CAs offer such certificates for free.)
4615 You will usually receive a combined certificate and private key in
4616 PKCS#12 format which \*(UA does not directly accept.
4617 To convert it to PEM format, use the following shell command:
4619 .Dl $ openssl pkcs12 \-in cert.p12 \-out cert.pem \-clcerts \-nodes
4621 If you omit the `\-nodes' parameter, you can specifiy an additional `PEM
4622 pass phrase' for protecting the private key.
4623 \*(UA will then ask you for that pass phrase each time it signs or
4627 .Dl set smime-sign-cert-myname@myisp.example=cert.pem
4629 to make this private key and certificate known to \*(UA.
4630 You can now sign outgoing messages.
4636 From each signed message you send,
4637 the recipient can fetch your certificate and use it to send encrypted
4639 Accordingly if somebody sends you a signed message, you can do the same.
4642 command to check the validity of the certificate.
4643 After that, retrieve the certificate and tell \*(UA that it should use
4646 .Dl certsave filename
4647 .Dl set smime-encrypt-USER@HOST=filename
4649 You should carefully consider if you prefer to store encrypted messages
4651 If you do, anybody who has access to your mail folders can read them,
4652 but if you do not, you might be unable to read them yourself later if
4653 you happen to lose your private key.
4656 command saves messages in decrypted form, while the
4661 commands leave them encrypted.
4663 Note that neither S/MIME signing nor encryption applies to message
4664 subjects or other header fields.
4665 Thus they may not contain sensitive information for encrypted messages,
4666 and cannot be trusted even if the message content has been verified.
4667 When sending signed messages,
4668 it is recommended to repeat any important header information in the
4672 .\" .Ss "Using CRLs with S/MIME or SSL/TLS" {{{
4673 .Ss "Using CRLs with S/MIME or SSL/TLS"
4674 \*(OP Certification authorities (CAs) issue certificate revocation
4675 lists (CRLs) on a regular basis.
4676 These lists contain the serial numbers of certificates that have been
4677 declared invalid after they have been issued.
4678 Such usually happens because the private key for the certificate has
4680 because the owner of the certificate has left the organization that is
4681 mentioned in the certificate, etc.
4682 To seriously use S/MIME or SSL/TLS verification,
4683 an up-to-date CRL is required for each trusted CA.
4684 There is otherwise no method to distinguish between valid and
4685 invalidated certificates.
4686 \*(UA currently offers no mechanism to fetch CRLs, nor to access them on
4687 the Internet, so you have to retrieve them by some external mechanism.
4689 \*(UA accepts CRLs in PEM format only;
4690 CRLs in DER format must be converted, like, e.\|g.:
4692 .Dl $ openssl crl \-inform DER \-in crl.der \-out crl.pem
4694 To tell \*(UA about the CRLs, a directory that contains all CRL files
4695 (and no other files) must be created.
4700 variables, respectively, must then be set to point to that directory.
4701 After that, \*(UA requires a CRL to be present for each CA that is used
4702 to verify a certificate.
4705 .\" .Ss "Handling spam" {{{
4707 \*(OP \*(UA can make use of spam detection and learning facilities \(en
4708 more precisely, SpamAssassin (\%<http://spamassassin.apache.org>).
4709 A very comprehensive documentation of
4711 can be found at the O'Reilly Commons
4712 (\%<http://commons.oreilly.com/wiki/index.php/SpamAssassin>).
4714 Currently \*(UA supports interaction with
4716 only via its daemonized
4719 server / client pair, which means that, in order to detect and work
4720 with spam through \*(UA, an instance of the
4722 daemon must be running (the examples are equivalent):
4723 .Bd -literal -offset indent
4724 $ spamd -i localhost:2142 -i /tmp/.spamsock -d [-L] [-l]
4725 $ spamd --listen=localhost:2142 --listen=/tmp/.spamsock \\
4726 --daemonize [--local] [--allow-tell]
4731 should only listen on a local, path-based UNIX domain socket instead of
4732 offering its service over the network, it maybe necessary to use
4735 option instead of the shown
4737 In order to support training of the Bayesian classifier through \*(UA,
4739 must have been started with the
4745 is running \*(UA can classify messages by using the client side program,
4748 .Bd -literal -offset indent
4749 $ \*(ua -Sspam-command=/usr/local/bin/spamc \\
4750 -Sspam-socket=/tmp/.spamsock -Sspam-maxsize=500000
4753 The commands offered are
4757 which simply set an `is-spam' flag that can be used for, e.g., message
4760 which passes messages through to the spam detector in order to gain
4761 a spam score and conditionally set the `is-spam' flag accordingly,
4762 as well as the Bayesian filter related
4768 Because messages must exist on local storage in order to be scored (or
4769 used for Bayesian filter training), it is possibly a good idea to
4770 perform the local spam check last:
4771 .Bd -literal -offset indent
4772 define spamdelhook {
4774 spamset (header x-dcc-brand-metrics "bulk")
4775 # Server-side spamassassin(1)
4776 spamset (header x-spam-flag "YES")
4777 del :s # TODO we HAVE to be able to do `spamrate :u ! :s'
4778 # And finally the local spamc(1)
4782 set folder-hook-FOLDER=spamdelhook
4785 See also the documentation for the variables
4795 .\" .Ss "Sending mail from scripts" {{{
4796 .Ss "Sending mail from scripts"
4797 If you want to send mail from scripts, you must be aware that \*(UA
4798 reads the user's configuration files by default.
4799 So unless your script is only intended for your own personal use
4800 (as, e.g., a cron job), you need to circumvent this:
4802 .Dl MAILRC=/dev/null \*(ua \-n
4804 You then need to create a script-local configuration for \*(UA.
4805 This can be done by either pointing the
4807 variable to a custom configuration file,
4808 by passing the configuration in environment variables,
4811 command line option to specify options.
4812 Since many configuration options are not valid shell variables, the
4814 command is useful if the approach via environment variables is used:
4815 .Bd -literal -offset indent
4816 env MAILRC=/dev/null password=secret \*(ua -n -Sv15-compat \e
4817 -S 'smtp=smtps://mylogin@some.host:465' -Ssmtp-auth=login \e
4818 -S 'from=scriptreply@domain' \e
4819 -s 'subject' -a attachment_file recipient@domain < content_file
4824 .\" .Sh "SEE ALSO" {{{
4837 .Xr spamassassin 1 ,
4855 .\" .Sh "IMPLEMENTATION NOTES" {{{
4856 .Sh "IMPLEMENTATION NOTES"
4857 The character set conversion uses and relies upon the
4860 Its functionality differs widely between the various system environments
4863 Limitations with IMAP mailboxes are:
4864 It is not possible to edit messages, but it is possible to append them.
4865 Thus to edit a message, create a local copy of it, edit it, append it,
4866 and delete the original.
4867 The line count for the header display is only appropriate if the entire
4868 message has been downloaded from the server.
4869 The marking of messages as `new' is performed by the IMAP server;
4874 will not cause it to be reset, and if the
4876 variable is unset, messages that arrived during a session will not be
4877 in state `new' anymore when the folder is opened again.
4878 Also if commands queued in disconnected mode are committed,
4879 the IMAP server will delete the `new' flag for all messages in the
4881 and new messages will appear as unread when it is selected for viewing
4883 The `flagged', `answered', and `draft' attributes are usually permanent,
4884 but some IMAP servers are known to drop them without notification.
4885 Message numbers may change with IMAP every time before the prompt is
4886 printed if \*(UA is notified by the server that messages have been
4887 deleted by some other client or process.
4888 In this case, `Expunged n messages' is printed, and message numbers may
4891 Limitations with POP3 mailboxes are:
4892 It is not possible to edit messages, they can only be copied and deleted.
4893 The line count for the header display is only appropriate if the entire
4894 message has been downloaded from the server.
4895 The status field of a message is maintained by the server between
4896 connections; some servers do not update it at all, and with a server
4897 that does, the `exit' command will not cause the message status to be
4899 The `newmail' command and the `newmail' variable have no effect.
4900 It is not possible to rename or to remove POP3 mailboxes.
4902 If a `RUBOUT' (interrupt, `control-C') is typed while an IMAP or POP3
4903 operation is in progress, \*(UA will wait until the operation can be
4905 and will then return to the command loop and print the prompt again.
4906 When a second `RUBOUT' is typed while \*(UA is waiting for the operation
4907 to complete, the operation itself will be cancelled.
4908 In this case, data that has not been fetched yet will have to be fetched
4909 before the next command can be performed.
4910 If the cancelled operation was using an SSL/TLS encrypted channel,
4911 an error in the SSL transport will very likely result and render the
4912 connection unusable.
4914 As \*(UA is a mail user agent, it provides only basic SMTP services.
4915 If it fails to contact its upstream SMTP server, it will not make
4916 further attempts to transfer the message at a later time,
4917 and it does not leave other information about this condition than an
4918 error message on the terminal and an entry in
4920 This is usually not a problem if the SMTP server is located in the same
4921 local network as the computer on which \*(UA is run.
4922 However, care should be taken when using a remote server of an ISP;
4923 it might be better to set up a local SMTP server then which just acts as
4926 \*(UA immediately contacts the SMTP server (or
4928 ) even when operating in
4931 It would not make much sense for \*(UA to defer outgoing mail since SMTP
4932 servers usually provide much more elaborated delay handling than \*(UA
4933 could perform as a client.
4934 Thus the recommended setup for sending mail in
4936 mode is to configure a local SMTP server such that it sends outgoing
4937 mail as soon as an external network connection is available again,
4938 i.e., to advise it to do that from a network startup script.
4943 A \fImail\fR command appeared in Version 1 AT&T Unix.
4944 Berkeley Mail was written in 1978 by Kurt Shoens.
4945 This man page is derived from from The Mail Reference Manual originally
4946 written by Kurt Shoens.
4947 "Heirloom Mailx" enhancements are maintained and documented by Gunnar
4949 "S-nail" is maintained and documented by Steffen (Daode) Nurpmeso.
4951 Portions of this text are reprinted and reproduced in electronic form
4952 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
4953 \(en Operating System Interface (POSIX), The Open Group Base
4954 Specifications Issue 6, Copyright \(co 2001-2003 by the Institute of
4955 Electrical and Electronics Engineers, Inc and The Open Group.
4956 In the event of any discrepancy between this version and the original
4957 IEEE and The Open Group Standard, the original IEEE and The Open Group
4958 Standard is the referee document.
4959 The original Standard can be obtained online at
4960 \%<http://www.opengroup.org/unix/online.html>.
4961 Redistribution of this material is permitted so long as this notice
4967 .An "Christos Zoulas" ,
4968 .An "Gunnar Ritter" ,
4969 .An Steffen Po Daode Pc Nurpmeso Aq s-nail-users@lists.sourceforge.net
4972 Too many (see the file `TODO' from the distribution or the repository).