1MAILX(1) User Commands MAILX(1)
2
6 nail - send and receive Internet mail
7
9 nail [-BDdFintv~] [-s subject] [-a attachment ] [-c cc-addr] [-b bcc-
10 addr] [-r from-addr] [-h hops] [-A account] [-S vari‐
11 able[=value]] to-addr . . .
12 nail [-BDdeHiInNRv~] [-T name] [-A account] [-S variable[=value]] -f
13 [name]
14 nail [-BDdeinNRv~] [-A account] [-S variable[=value]] [-u user]
15
17 Nail is an intelligent mail processing system, which has a command syn‐
18 tax reminiscent of ed(1) with lines replaced by messages. It is based
19 on Berkeley Mail 8.1, is intended to provide the functionality of the
20 POSIX nail command, and offers extensions for MIME, IMAP, POP3, SMTP,
21 and S/MIME. Nail provides enhanced features for interactive use, such
22 as caching and disconnected operation for IMAP, message threading,
23 scoring, and filtering. It is also usable as a mail batch language,
24 both for sending and receiving mail.
25 The following options are accepted:
27 -A name
29 Executes an account command (see below) for name after the
30 startup files have been read.
31 -a file
33 Attach the given file to the message.
34 -B Make standard input and standard output line-buffered.
36 -b address
38 Send blind carbon copies to list. List should be a comma-sepa‐
39 rated list of names.
40 -c address
42 Send carbon copies to list of users.
43 -D Start in disconnected mode; see the description for the discon‐
45 nected variable option.
46 -d Enables debugging messages and disables the actual delivery of
48 messages. Unlike -v, this option is intended for nail develop‐
49 ment only.
50 -e Just check if mail is present in the system mailbox. If yes,
52 return an exit status of zero, else, a non-zero value.
53 -f [file]
55 Read in the contents of the user's mbox (or the specified file)
56 for processing; when nail is quit, it writes undeleted messages
57 back to this file. The string file is handled as described for
58 the folder command below.
59 -F Save the message to send in a file named after the local part of
61 the first recipient's address.
62 -H Print header summaries for all messages and exit.
64 -h hops
66 Invoke sendmail with the specified hop count. This option has
67 no effect when SMTP is used for sending mail.
68 -i Ignore tty interrupt signals. This is particularly useful when
70 using nail on noisy phone lines.
71 -I Shows the `Newsgroup:' or `Article-Id:' fields in the header
73 summary. Only applicable in combination with -f.
74 -n Inhibits reading /etc/nail.rc upon startup. This option should
76 be activated for nail scripts that are invoked on more than one
77 machine, because the contents of that file may differ between
78 them.
79 -N Inhibits the initial display of message headers when reading
81 mail or editing a mail folder.
82 -q file
84 Start the message with the contents of the specified file. May
85 be given in send mode only.
86 -r address
88 Sets the From address. Overrides any from variable specified in
89 environment or startup files. Tilde escapes are disabled. The
90 -r address options are passed to the mail transfer agent unless
91 SMTP is used. This option exists for compatibility only; it is
92 recommended to set the from variable directly instead.
93 -R Opens any folders read-only.
95 -s subject
97 Specify subject on command line (only the first argument after
98 the -s flag is used as a subject; be careful to quote subjects
99 containing spaces).
100 -S variable[=value]
102 Sets the internal option variable and, in case of a string
103 option, assigns value to it.
104 -T name
106 Writes the `Message-Id:' and `Article-Id:' header fields of each
107 message read in the file name. Implies -I. Compressed files
108 are handled as described for the folder command below.
109 -t The message to be sent is expected to contain a message header
111 with `To:', `Cc:', or `Bcc:' fields giving its recipients.
112 Recipients specified on the command line are ignored.
113 -u user
115 Reads the mailbox of the given user name.
116 -v Verbose mode. The details of delivery are displayed on the
118 user's terminal.
119 -V Print nail's version and exit.
121 -~ Enable tilde escapes even if not in interactive mode.
123 Sending mail
125 To send a message to one or more people, nail can be invoked with argu‐
126 ments which are the names of people to whom the mail will be sent. The
127 user is then expected to type in his message, followed by an `control-
128 D' at the beginning of a line. The section below Replying to or origi‐
129 nating mail, describes some features of nail available to help when
130 composing letters.
131 Reading mail
133 In normal usage nail is given no arguments and checks the user's mail
134 out of the post office, then prints out a one line header of each mes‐
135 sage found. The current message is initially the first message (num‐
136 bered 1) and can be printed using the print command which can be abbre‐
137 viated `p'). The user can move among the messages much as he moves
138 between lines in ed(1), with the commands `+' and `-' moving backwards
139 and forwards, and simple numbers.
140 Disposing of mail
142 After examining a message the user can delete `d') the message or reply
143 `r') to it. Deletion causes the nail program to forget about the mes‐
144 sage. This is not irreversible; the message can be undeleted `u') by
145 giving its number, or the nail session can be aborted by giving the
146 exit `x') command. Deleted messages will, however, usually disappear
147 never to be seen again.
148 Specifying messages
150 Commands such as print and delete can be given a list of message num‐
151 bers as arguments to apply to a number of messages at once. Thus
152 `delete 1 2' deletes messages 1 and 2, while `delete 1-5' deletes mes‐
153 sages 1 through 5. In sorted or threaded mode (see the sort and thread
154 commands), `delete 1-5' deletes the messages that are located between
155 (and including) messages 1 through 5 in the sorted/threaded order, as
156 shown in the header summary. The following special message names
157 exist:
158 :n All new messages.
160 :o All old messages (any not in state read or new).
162 :u All unread messages.
164 :d All deleted messages (for the undelete command).
166 :r All read messages.
168 :f All `flagged' messages.
170 :a All answered messages (cf. the markanswered variable).
172 :t All messages marked as draft.
174 :k All `killed' messages.
176 :j All messages classified as junk.
178 . The current message.
180 ; The message that was previously the current message.
182 , The parent message of the current message, that is the message
184 with the Message-ID given in the `In-Reply-To:' field or the
185 last entry of the `References:' field of the current message.
186 - The next previous undeleted message, or the next previous
188 deleted message for the undelete command. In sorted/threaded
189 mode, the next previous such message in the sorted/threaded
190 order.
191 + The next undeleted message, or the next deleted message for the
193 undelete command. In sorted/threaded mode, the next such mes‐
194 sage in the sorted/threaded order.
195 ^ The first undeleted message, or the first deleted message for
197 the undelete command. In sorted/threaded mode, the first such
198 message in the sorted/threaded order.
199 $ The last message. In sorted/threaded mode, the last message in
201 the sorted/threaded order.
202 &x In threaded mode, selects the message addressed with x, where x
204 is any other message specification, and all messages from the
205 thread that begins at it. Otherwise, it is identical to x. If
206 x is omitted, the thread beginning with the current message is
207 selected.
208 * All messages.
210 ` All messages that were included in the message list for the pre‐
212 vious command.
213 /string
215 All messages that contain string in the subject field (case
216 ignored). See also the searchheaders variable. If string is
217 empty, the string from the previous specification of that type
218 is used again.
219 address
221 All messages from address.
222 (criterion)
224 All messages that satisfy the given IMAP-style SEARCH criterion.
225 This addressing mode is available with all types of folders; for
226 folders not located on IMAP servers, or for servers unable to
227 execute the SEARCH command, nail will perform the search
228 locally. Strings must be enclosed by double quotes `"' in their
229 entirety if they contain white space or parentheses; within the
230 quotes, only backslash `\' is recognized as an escape character.
231 All string searches are case-insensitive. When the description
232 indicates that the `envelope' representation of an address field
233 is used, this means that the search string is checked against
234 both a list constructed as
235 ("real name" "source-route" "local-part" "domain-part")
237 for each address, and the addresses without real names from the
239 respective header field. Criteria can be nested using parenthe‐
240 ses.
241 (criterion1 criterion2 ... criterionN)
243 All messages that satisfy all of the given criteria.
244 (or criterion1 criterion2)
246 All messages that satisfy either criterion1 or criterion2, or
247 both. To connect more than two criteria using `or', (or) speci‐
248 fications have to be nested using additional parentheses, as
249 with `(or a (or b c))'; `(or a b c)' means ((a or b) and c).
250 For a simple `or' operation of independent criteria on the low‐
251 est nesting level, it is possible to achieve similar effects by
252 using three separate criteria, as with `(a) (b) (c)'.
253 (not criterion)
255 All messages that do not satisfy criterion.
256 (bcc string)
258 All messages that contain string in the `envelope' representa‐
259 tion of the Bcc: field.
260 (cc string)
262 All messages that contain string in the `envelope' representa‐
263 tion of the Cc: field.
264 (from string)
266 All messages that contain string in the `envelope' representa‐
267 tion of the From: field.
268 (subject string)
270 All messages that contain string in the Subject: field.
271 (to string)
273 All messages that contain string in the `envelope' representa‐
274 tion of the To: field.
275 (header name string)
277 All messages that contain string in the specified Name: field.
278 (body string)
280 All messages that contain string in their body.
281 (text string)
283 All messages that contain string in their header or body.
284 (larger size)
286 All messages that are larger than size (in bytes).
287 (smaller size)
289 All messages that are smaller than size (in bytes).
290 (before date)
292 All messages that were received before date; date must be in the
293 form d[d]-mon-yyyy, where d[d] is the day of the month as one or
294 two digits, mon is the name of the month—one of `Jan', `Feb',
295 `Mar', `Apr', `May', `Jun', `Jul', `Aug', `Sep', `Oct', `Nov',
296 or `Dec', and yyyy is the year as four digits; e.g.
297 "30-Aug-2004".
298 (on date)
300 All messages that were received on the specified date.
301 (since date)
303 All messages that were received since the specified date.
304 (sentbefore date)
306 All messages that were sent on the specified date.
307 (senton date)
309 All messages that were sent on the specified date.
310 (sentsince date)
312 All messages that were sent since the specified date.
313 () The same criterion as for the previous search. This specifica‐
315 tion cannot be used as part of another criterion. If the previ‐
316 ous command line contained more than one independent criterion,
317 the last of those criteria is used.
318 A practical method to read a set of messages is to issue a from command
320 with the search criteria first to check for appropriate messages, and
321 to read each single message then by typing ``' repeatedly.
322 Replying to or originating mail
324 The reply command can be used to set up a response to a message, send‐
325 ing it back to the person who it was from. Text the user types in
326 then, up to an end-of-file, defines the contents of the message. While
327 the user is composing a message, nail treats lines beginning with the
328 character `~' specially. For instance, typing `~m' (alone on a line)
329 will place a copy of the current message into the response right shift‐
330 ing it by a tabstop (see indentprefix variable, below). Other escapes
331 will set up subject fields, add and delete recipients to the message,
332 attach files to it and allow the user to escape to an editor to revise
333 the message or to a shell to run some commands. (These options are
334 given in the summary below.)
335 Ending a mail processing session
337 The user can end a nail session with the quit (`q') command. Messages
338 which have been examined go to the user's mbox file unless they have
339 been deleted in which case they are discarded. Unexamined messages go
340 back to the post office. (See the -f option above).
341 Personal and systemwide distribution lists
343 It is also possible to create a personal distribution lists so that,
344 for instance, the user can send mail to `cohorts' and have it go to a
345 group of people. Such lists can be defined by placing a line like
346 alias cohorts bill ozalp jkf mark kridle@ucbcory
348 in the file .mailrc in the user's home directory. The current list of
350 such aliases can be displayed with the alias command in nail. System
351 wide distribution lists can be created by editing /etc/aliases, see
352 aliases(5) and sendmail(8); these are kept in a different syntax. In
353 mail the user sends, personal aliases will be expanded in mail sent to
354 others so that they will be able to reply to the recipients. System
355 wide aliases are not expanded when the mail is sent, but any reply
356 returned to the machine will have the system wide alias expanded as all
357 mail goes through sendmail.
358 Recipient address specifications
360 When an address is used to name a recipient (in any of To, Cc, or Bcc),
361 names of local mail folders and pipes to external commands can also be
362 specified; the message text is then written to them. The rules are:
363 Any name which starts with a `|' character specifies a pipe, the com‐
364 mand string following the `|' is executed and the message is sent to
365 its standard input; any other name which contains a `@' character is
366 treated as a mail address; any other name which starts with a `+' char‐
367 acter specifies a folder name; any other name which contains a `/'
368 character but no `!' or `%' character before also specifies a folder
369 name; what remains is treated as a mail address. Compressed folders
370 are handled as described for the folder command below.
371 Network mail (Internet / ARPA, UUCP, Berknet)
373 See mailaddr(7) for a description of network addresses. Nail has a
374 number of options which can be set in the .mailrc file to alter its
375 behavior; thus `set askcc' enables the askcc feature. (These options
376 are summarized below).
377 MIME types
379 For any outgoing attachment, nail tries to determine the content type.
380 It does this by reading MIME type files whose lines have the following
381 syntax:
382 type/subtype extension [extension . . .]
384 where type/subtype are strings describing the file contents, and exten‐
386 sion is the part of a filename starting after the last dot. Any line
387 not immediately beginning with an ASCII alphabetical character is
388 ignored by nail. If there is a match with the extension of the file to
389 attach, the given type/subtype pair is used. Otherwise, or if the
390 filename has no extension, the content types text/plain or applica‐
391 tion/octet-stream are used, the first for text or international text
392 files, the second for any file that contains formatting characters
393 other than newlines and horizontal tabulators.
394 Character sets
396 Nail normally detects the character set of the terminal using the
397 LC_CTYPE locale setting. If the locale cannot be used appropriately,
398 the ttycharset variable should be set to provide an explicit value.
399 When reading messages, their text is converted to the terminal charac‐
400 ter set if possible. Unprintable characters and illegal byte sequences
401 are detected and replaced by Unicode substitute characters or question
402 marks unless the print-all-chars is set at initialization time.
403 The character set for outgoing messages is not necessarily the same as
405 the one used on the terminal. If an outgoing text message contains
406 characters not representable in US-ASCII, the character set being used
407 must be declared within its header. Permissible values can be declared
408 using the sendcharsets variable, separated by commas; nail tries each
409 of the values in order and uses the first appropriate one. If the mes‐
410 sage contains characters that cannot be represented in any of the given
411 character sets, the message will not be sent, and its text will be
412 saved to the `dead.letter' file. Messages that contain NUL bytes are
413 not converted.
414 Outgoing attachments are converted if they are plain text. If the
416 sendcharsets variable contains more than one character set name, the ~@
417 tilde escape will ask for the character sets for individual attachments
418 if it is invoked without arguments.
419 Best results are usually achieved when nail is run in a UTF-8 locale on
421 a UTF-8 capable terminal. In this setup, characters from various coun‐
422 tries can be displayed, while it is still possible to use more simple
423 character sets for sending to retain maximum compatibility with older
424 mail clients.
425 Commands
427 Each command is typed on a line by itself, and may take arguments fol‐
428 lowing the command word. The command need not be typed in its entirety
429 – the first command which matches the typed prefix is used. For com‐
430 mands which take message lists as arguments, if no message list is
431 given, then the next message forward which satisfies the command's
432 requirements is used. If there are no messages forward of the current
433 message, the search proceeds backwards, and if there are no good mes‐
434 sages at all, nail types `applicable messages' and aborts the command.
435 If the command begins with a # sign, the line is ignored.
436 The arguments to commands can be quoted, using the following methods:
438 · An argument can be enclosed between paired double-quotes "" or
440 single-quotes ''; any white space, shell word expansion, or
441 backslash characters within the quotes are treated literally as
442 part of the argument. A double-quote will be treated literally
443 within single-quotes and vice versa. These special properties of
444 the quote marks occur only when they are paired at the beginning
445 and end of the argument.
446 · A backslash outside of the enclosing quotes is discarded and the
448 following character is treated literally as part of the argu‐
449 ment.
450 · An unquoted backslash at the end of a command line is discarded
452 and the next line continues the command.
453 Filenames, where expected, are subjected to the following transforma‐
455 tions, in sequence:
456 · If the filename begins with an unquoted plus sign, and the
458 folder variable is defined, the plus sign will be replaced by
459 the value of the folder variable followed by a slash. If the
460 folder variable is unset or is set to null, the filename will be
461 unchanged.
462 · Shell word expansions are applied to the filename. If more than
464 a single pathname results from this expansion and the command is
465 expecting one file, an error results.
466 The following commands are provided:
468 - Print out the preceding message. If given a numeric argument n,
470 goes to the n'th previous message and prints it.
471 ? Prints a brief summary of commands.
473 ! Executes the shell (see sh(1) and csh(1)) command which follows.
475 | A synonym for the pipe command.
477 account
479 (ac) Creates, selects or lists an email account. An account is
480 formed by a group of commands, primarily of those to set vari‐
481 ables. With two arguments, of which the second is a `{', the
482 first argument gives an account name, and the following lines
483 create a group of commands for that account until a line con‐
484 taining a single `}' appears. With one argument, the previously
485 created group of commands for the account name is executed, and
486 a folder command is executed for the system mailbox or inbox of
487 that account. Without arguments, the list of accounts and their
488 contents are printed. As an example,
489 account myisp {
491 set folder=imaps://mylogin@imap.myisp.example
492 set record=+Sent
493 set from="myname@myisp.example (My Name)"
494 set smtp=smtp.myisp.example
495 }
496 creates an account named `myisp' which can later be selected by
498 specifying `account myisp'.
499 alias (a) With no arguments, prints out all currently-defined aliases.
501 With one argument, prints out that alias. With more than one
502 argument, creates a new alias or changes an old one.
503 alternates
505 (alt) The alternates command is useful if the user has accounts
506 on several machines. It can be used to inform nail that the
507 listed addresses all belong to the invoking user. When he
508 replies to messages, nail will not send a copy of the message to
509 any of the addresses listed on the alternates list. If the
510 alternates command is given with no argument, the current set of
511 alternate names is displayed.
512 answered
514 (ans) Takes a message list and marks each message as a having
515 been answered. This mark has no technical meaning in the mail
516 system; it just causes messages to be marked in the header sum‐
517 mary, and makes them specially addressable.
518 cache Only applicable to cached IMAP mailboxes; takes a message list
520 and reads the specified messages into the IMAP cache.
521 call Calls a macro (see the define command).
523 cd Same as chdir.
525 certsave
527 Only applicable to S/MIME signed messages. Takes a message list
528 and a file name and saves the certificates contained within the
529 message signatures to the named file in both human-readable and
530 PEM format. The certificates can later be used to send
531 encrypted messages to the messages' originators by setting the
532 smime-encrypt-user@host variable.
533 chdir (ch) Changes the user's working directory to that specified, if
535 given. If no directory is given, then changes to the user's
536 login directory.
537 classify
539 (cl) Takes a list of messages and examines their contents for
540 characteristics of junk mail using Bayesian filtering. Messages
541 considered to be junk are then marked as such. The junk mail
542 database is not changed.
543 collapse
545 (coll) Only applicable to threaded mode. Takes a message list
546 and makes all replies to these messages invisible in header sum‐
547 maries, unless they are in state `new'.
548 connect
550 (conn) If operating in disconnected mode on an IMAP mailbox,
551 switch to online mode and connect to the mail server while
552 retaining the mailbox status. See the description of the dis‐
553 connected variable for more information.
554 copy (c) The copy command does the same thing that save does, except
556 that it does not mark the messages it is used on for deletion
557 when the user quits. Compressed files and IMAP mailboxes are
558 handled as described for the folder command.
559 Copy (C) Similar to copy, but saves the messages in a file named
561 after the local part of the sender address of the first message.
562 decrypt
564 (dec) For unencrypted messages, this command is identical to
565 copy. Encrypted messages are first decrypted, if possible, and
566 then copied.
567 Decrypt
569 (Dec) Similar to decrypt, but saves the messages in a file named
570 after the local part of the sender address of the first message.
571 define (def) Defines a macro. A macro definition is a sequence of com‐
573 mands in the following form:
574 define name {
576 command1
577 command2
578 ...
579 commandN
580 }
581 Once defined, a macro can be explicitly invoked using the call
583 command, or can be implicitly invoked by setting the folder-hook
584 or folder-hook-fullname variables.
585 defines
587 Prints the currently defined macros including their contents.
588 delete (d) Takes a list of messages as argument and marks them all as
590 deleted. Deleted messages will not be saved in mbox, nor will
591 they be available for most other commands.
592 discard
594 Same as ignore.
595 disconnect
597 (disco) If operating in online mode on an IMAP mailbox, switch
598 to disconnected mode while retaining the mailbox status. See
599 the description of the disconnected variable for more informa‐
600 tion. A list of messages may optionally be given as argument;
601 the respective messages are then read into the cache before the
602 connection is closed. Thus `disco *' makes the entire current
603 mailbox available for disconnected use.
604 dp or dt
606 Deletes the current message and prints the next message. If
607 there is no next message, nail says `at EOF'.
608 draft Takes a message list and marks each message as a draft. This
610 mark has no technical meaning in the mail system; it just causes
611 messages to be marked in the header summary, and makes them spe‐
612 cially addressable.
613 echo Echoes its arguments, resolving special names as documented for
615 the folder command. The escape sequences `\a', `\b', `\c',
616 `\f', `\n', `\r', `\t', `\v', `\\', and `\0num' are interpreted
617 as with the echo(1) command.
618 edit (e) Takes a list of messages and points the text editor at each
620 one in turn. Modified contents are discarded unless the write‐
621 backedited variable is set.
622 else Marks the end of the then-part of an if statement and the begin‐
624 ning of the part to take effect if the condition of the if
625 statement is false.
626 endif Marks the end of an if statement.
628 exit (ex or x) Effects an immediate return to the Shell without modi‐
630 fying the user's system mailbox, his mbox file, or his edit file
631 in -f.
632 file (fi) The same as folder.
634 flag (fl) Takes a message list and marks the messages as `flagged'
636 for urgent/special attention. This mark has no technical mean‐
637 ing in the mail system; it just causes messages to be high‐
638 lighted in the header summary, and makes them specially address‐
639 able.
640 folders
642 With no arguments, list the names of the folders in the folder
643 directory. With an existing folder as an argument, lists then
644 names of folders below the named folder; e.g. the command `fold‐
645 ers @' lists the folders on the base level of the current IMAP
646 server. See also the imap-list-depth variable.
647 folder (fold) The folder command switches to a new mail file or folder.
649 With no arguments, it tells the user which file he is currently
650 reading. If an argument is given, it will write out changes
651 (such as deletions) the user has made in the current file and
652 read in the new file. Some special conventions are recognized
653 for the name. # means the previous file, % means the invoking
654 user's system mailbox, %user means user's system mailbox, &
655 means the invoking user's mbox file, and +file means a file in
656 the folder directory. %:filespec expands to the same value as
657 filespec, but the file is handled as a system mailbox e. g. by
658 the mbox and save commands. If the name matches one of the
659 strings defined with the shortcut command, it is replaced by its
660 long form and expanded. If the name ends with .gz or .bz2, it
661 is treated as compressed with gzip(1) or bzip2(1), respectively.
662 Likewise, if name does not exist, but either name.gz or name.bz2
663 exists, the compressed file is used. If name refers to a direc‐
664 tory with the subdirectories `tmp', `new', and `cur', it is
665 treated as a folder in maildir format. A name of the form
666 protocol://[user@]host[:port][/file]
668 is taken as an Internet mailbox specification. The supported
670 protocols are currently imap (IMAP v4r1), imaps (IMAP with
671 SSL/TLS encryption), pop3 (POP3), and pop3s (POP3 with SSL/TLS
672 encryption). If user contains special characters, in particular
673 `/' or `%', they must be escaped in URL notation, as `%2F' or
674 `%25'. The optional file part applies to IMAP only; if it is
675 omitted, the default `INBOX' is used. If nail is connected to
676 an IMAP server, a name of the form @mailbox refers to the mail‐
677 box on that server. If the `folder' variable refers to an IMAP
678 account, the special name `%' selects the `INBOX' on that
679 account.
680 Followup
682 (F) Similar to Respond, but saves the message in a file named
683 after the local part of the first recipient's address.
684 followup
686 (fo) Similar to respond, but saves the message in a file named
687 after the local part of the first recipient's address.
688 followupall
690 Similar to followup, but responds to all recipients regardless
691 of the flipr and Replyall variables.
692 followupsender
694 Similar to Followup, but responds to the sender only regardless
695 of the flipr and Replyall variables.
696 forward
698 (fwd) Takes a message and the address of a recipient and for‐
699 wards the message to him. The text of the original message is
700 included in the new one, with the value of the fwdheading vari‐
701 able printed before. The fwdignore and fwdretain commands spec‐
702 ify which header fields are included in the new message. Only
703 the first part of a multipart message is included unless the
704 forward-as-attachment option is set.
705 Forward
707 (Fwd) Similar to forward, but saves the message in a file named
708 after the local part of the recipient's address.
709 from (f) Takes a list of messages and prints their message headers,
711 piped through the pager if the output does not fit on the
712 screen.
713 fwdignore
715 Specifies which header fields are to be ignored with the forward
716 command. This command has no effect when the forward-as-attach‐
717 ment option is set.
718 fwdretain
720 Specifies which header fields are to be retained with the for‐
721 ward command. fwdretain overrides fwdignore. This command has
722 no effect when the forward-as-attachment option is set.
723 good (go) Takes a list of messages and marks all of them as not being
725 junk mail. Data from these messages is then inserted into the
726 junk mail database for future classification.
727 headers
729 (h) Lists the current range of headers, which is an 18-message
730 group. If a `+' argument is given, then the next 18-message
731 group is printed, and if a `-' argument is given, the previous
732 18-message group is printed.
733 help A synonym for ?.
735 hold (ho, also preserve) Takes a message list and marks each message
737 therein to be saved in the user's system mailbox instead of in
738 mbox. Does not override the delete command. nail deviates from
739 the POSIX standard with this command, as a `next' command issued
740 after `hold' will display the following message, not the current
741 one.
742 if Commands in nail's startup files can be executed conditionally
744 depending on whether the user is sending or receiving mail with
745 the if command. For example:
746 if receive
748 commands . . .
749 endif
750 An else form is also available:
752 if receive
754 commands . . .
755 else
756 commands . . .
757 endif
758 Note that the only allowed conditions are receive, send, and
760 term (execute command if standard input is a tty).
761 ignore Add the list of header fields named to the ignored list. Header
763 fields in the ignore list are not printed on the terminal when a
764 message is printed. This command is very handy for suppression
765 of certain machine-generated header fields. The Type and Print
766 commands can be used to print a message in its entirety, includ‐
767 ing ignored fields. If ignore is executed with no arguments, it
768 lists the current set of ignored fields.
769 imap Sends command strings directly to the current IMAP server. Nail
771 operates always in IMAP selected state on the current mailbox;
772 commands that change this will produce undesirable results and
773 should be avoided. Useful IMAP commands are:
774 create Takes the name of an IMAP mailbox as an argument and cre‐
776 ates it.
777 getquotaroot
779 Takes the name of an IMAP mailbox as an argument and
780 prints the quotas that apply to the mailbox. Not all
781 IMAP servers support this command.
782 namespace
784 Takes no arguments and prints the Personal Namespaces,
785 the Other User's Namespaces, and the Shared Namespaces.
786 Each namespace type is printed in parentheses; if there
787 are multiple namespaces of the same type, inner parenthe‐
788 ses separate them. For each namespace, a namespace pre‐
789 fix and a hierarchy separator is listed. Not all IMAP
790 servers support this command.
791 inc Same as newmail.
793 junk (j) Takes a list of messages and marks all of them as junk mail.
795 Data from these messages is then inserted into the junk mail
796 database for future classification.
797 kill (k) Takes a list of messages and `kills' them. Killed messages
799 are not printed in header summaries, and are ignored by the next
800 command. The kill command also sets the score of the messages
801 to negative infinity, so that subsequent score commands will not
802 unkill them again. Killing is only effective for the current
803 session on a folder; when it is quit, all messages are automati‐
804 cally unkilled.
805 list Prints the names of all available commands.
807 Mail (M) Similar to mail, but saves the message in a file named after
809 the local part of the first recipient's address.
810 mail (m) Takes as argument login names and distribution group names
812 and sends mail to those people.
813 mbox Indicate that a list of messages be sent to mbox in the user's
815 home directory when nail is quit. This is the default action
816 for messages if unless the hold option is set. nail deviates
817 from the POSIX standard with this command, as a `next' command
818 issued after `mbox' will display the following message, not the
819 current one.
820 move (mv) Acts like copy, but marks the messages for deletion if they
822 were transferred successfully.
823 Move (Mv) Similar to move, but moves the messages to a file named
825 after the local part of the sender address of the first message.
826 newmail
828 Checks for new mail in the current folder without committing any
829 changes before. If new mail is present, a message is printed.
830 If the header variable is set, the headers of each new message
831 are also printed.
832 next (n) like + or CR) Goes to the next message in sequence and types
834 it. With an argument list, types the next matching message.
835 New Same as unread.
837 new Same as unread.
839 online Same as connect.
841 noop If the current folder is located on an IMAP or POP3 server, a
843 NOOP command is sent. Otherwise, no operation is performed.
844 Pipe (Pi) Like pipe but also pipes ignored header fields and all
846 parts of MIME multipart/alternative messages.
847 pipe (pi) Takes a message list and a shell command and pipes the mes‐
849 sages through the command. Without an argument, the current
850 message is piped through the command given by the cmd variable.
851 If the page variable is set, every message is followed by a
852 formfeed character.
853 preserve
855 (pre) A synonym for hold.
856 Print (P) Like print but also prints out ignored header fields and all
858 parts of MIME multipart/alternative messages. See also print,
859 ignore, and retain.
860 print (p) Takes a message list and types out each message on the
862 user's terminal. If the message is a MIME multipart message,
863 all parts with a content type of `text' or `message' are shown,
864 the other are hidden except for their headers. Messages are
865 decrypted and converted to the terminal character set if neces‐
866 sary.
867 probability
869 (prob) For each word given as argument, the contents of its junk
870 mail database entry are printed.
871 quit (q) Terminates the session, saving all undeleted, unsaved mes‐
873 sages in the user's mbox file in his login directory, preserving
874 all messages marked with hold or preserve or never referenced in
875 his system mailbox, and removing all other messages from his
876 system mailbox. If new mail has arrived during the session, the
877 message `You have new mail' is given. If given while editing a
878 mailbox file with the -f flag, then the edit file is rewritten.
879 A return to the Shell is effected, unless the rewrite of edit
880 file fails, in which case the user can escape with the exit com‐
881 mand.
882 redirect
884 (red) Same as resend.
885 Redirect
887 (Red) Same as Resend.
888 remove (rem) Removes the named folders. The user is asked for confir‐
890 mation in interactive mode.
891 rename (ren) Takes the name of an existing folder and the name for the
893 new folder and renames the first to the second one. Both fold‐
894 ers must be of the same type and must be located on the current
895 server for IMAP.
896 Reply (R) Reply to originator. Does not reply to other recipients of
898 the original message.
899 reply (r) Takes a message list and sends mail to the sender and all
901 recipients of the specified message. The default message must
902 not be deleted.
903 replyall
905 Similar to reply, but responds to all recipients regardless of
906 the flipr and Replyall variables.
907 replysender
909 Similar to Reply, but responds to the sender only regardless of
910 the flipr and Replyall variables.
911 Resend Like resend, but does not add any header lines. This is not a
913 way to hide the sender's identity, but useful for sending a mes‐
914 sage again to the same recipients.
915 resend Takes a list of messages and a user name and sends each message
917 to the named user. `Resent-From:' and related header fields are
918 prepended to the new copy of the message.
919 Respond
921 Same as Reply.
922 respond
924 Same as reply.
925 respondall
927 Same as replyall.
928 respondsender
930 Same as replysender.
931 retain Add the list of header fields named to the retained list. Only
933 the header fields in the retain list are shown on the terminal
934 when a message is printed. All other header fields are sup‐
935 pressed. The Type and Print commands can be used to print a
936 message in its entirety. If retain is executed with no argu‐
937 ments, it lists the current set of retained fields.
938 Save (S) Similar to save, but saves the messages in a file named
940 after the local part of the sender of the first message instead
941 of taking a filename argument.
942 save (s) Takes a message list and a filename and appends each message
944 in turn to the end of the file. If no filename is given, the
945 mbox file is used. The filename in quotes, followed by the line
946 count and character count is echoed on the user's terminal. If
947 editing a system mailbox, the messages are marked for deletion.
948 Compressed files and IMAP mailboxes are handled as described for
949 the -f command line option above.
950 savediscard
952 Same as saveignore.
953 saveignore
955 Saveignore is to save what ignore is to print and type. Header
956 fields thus marked are filtered out when saving a message by
957 save or when automatically saving to mbox. This command should
958 only be applied to header fields that do not contain information
959 needed to decode the message, as MIME content fields do. If
960 saving messages on an IMAP account, ignoring fields makes it
961 impossible to copy the data directly on the server, thus opera‐
962 tion usually becomes much slower.
963 saveretain
965 Saveretain is to save what retain is to print and type. Header
966 fields thus marked are the only ones saved with a message when
967 saving by save or when automatically saving to mbox. Saveretain
968 overrides saveignore. The use of this command is strongly dis‐
969 couraged since it may strip header fields that are needed to
970 decode the message correctly.
971 score (sc) Takes a message list and a floating point number and adds
973 the number to the score of each given message. All messages
974 start at score 0 when a folder is opened. When the score of a
975 message becomes negative, it is `killed' with the effects
976 described for the kill command; otherwise if it was negative
977 before and becomes positive, it is `unkilled'. Scores only
978 refer to the currently opened instance of a folder.
979 set (se) With no arguments, prints all variable values, piped
981 through the pager if the output does not fit on the screen.
982 Otherwise, sets option. Arguments are of the form option=value
983 (no space before or after =) or option. Quotation marks may be
984 placed around any part of the assignment statement to quote
985 blanks or tabs, i.e. `set indentprefix="->"'. If an argument
986 begins with no, as in `set nosave', the effect is the same as
987 invoking the unset command with the remaining part of the vari‐
988 able (`unset save').
989 seen Takes a message list and marks all messages as having been read.
991 shell (sh) Invokes an interactive version of the shell.
993 shortcut
995 Defines a shortcut name and its string for expansion, as
996 described for the folder command. With no arguments, a list of
997 defined shortcuts is printed.
998 show (Sh) Like print, but performs neither MIME decoding nor decryp‐
1000 tion so that the raw message text is shown.
1001 size Takes a message list and prints out the size in characters of
1003 each message.
1004 sort Create a sorted representation of the current folder, and change
1006 the next command and the addressing modes such that they refer
1007 to messages in the sorted order. Message numbers are the same
1008 as in regular mode. If the header variable is set, a header
1009 summary in the new order is also printed. Possible sorting cri‐
1010 teria are:
1011 date Sort the messages by their `Date:' field, that is by the
1013 time they were sent.
1014 from Sort messages by the value of their `From:' field, that
1016 is by the address of the sender. If the showname vari‐
1017 able is set, the sender's real name (if any) is used.
1018 size Sort the messages by their size.
1020 score Sort the messages by their score.
1022 status Sort the messages by their message status (new, read,
1024 old, etc.).
1025 subject
1027 Sort the messages by their subject.
1028 thread Create a threaded order, as with the thread command.
1030 to Sort messages by the value of their `To:' field, that is
1032 by the address of the recipient. If the showname vari‐
1033 able is set, the recipient's real name (if any) is used.
1034 If no argument is given, the current sorting criterion is
1036 printed.
1037 source The source command reads commands from a file.
1039 thread (th) Create a threaded representation of the current folder,
1041 i.e. indent messages that are replies to other messages in the
1042 header display, and change the next command and the addressing
1043 modes such that they refer to messages in the threaded order.
1044 Message numbers are the same as in unthreaded mode. If the
1045 header variable is set, a header summary in threaded order is
1046 also printed.
1047 top Takes a message list and prints the top few lines of each. The
1049 number of lines printed is controlled by the variable toplines
1050 and defaults to five.
1051 touch Takes a message list and marks the messages for saving in the
1053 mbox file. nail deviates from the POSIX standard with this com‐
1054 mand, as a `next' command issued after `mbox' will display the
1055 following message, not the current one.
1056 Type (T) Identical to the Print command.
1058 type (t) A synonym for print.
1060 unalias
1062 Takes a list of names defined by alias commands and discards the
1063 remembered groups of users. The group names no longer have any
1064 significance.
1065 unanswered
1067 Takes a message list and marks each message as not having been
1068 answered.
1069 uncollapse
1071 (unc) Only applicable to threaded mode. Takes a message list
1072 and makes the message and all replies to it visible in header
1073 summaries again. When a message becomes the current message, it
1074 is automatically made visible. Also when a message with col‐
1075 lapsed replies is printed, all of these are automatically uncol‐
1076 lapsed.
1077 undef Undefines each of the named macros. It is not an error to use a
1079 name that does not belong to one of the currently defined
1080 macros.
1081 undelete
1083 (u) Takes a message list and marks each message as not being
1084 deleted.
1085 undraft
1087 Takes a message list and marks each message as a draft.
1088 unflag Takes a message list and marks each message as not being
1090 `flagged'.
1091 unfwdignore
1093 Removes the header field names from the list of ignored fields
1094 for the forward command.
1095 unfwdretain
1097 Removes the header field names from the list of retained fields
1098 for the forward command.
1099 ungood Takes a message list and undoes the effect of a good command
1101 that was previously applied on exactly these messages.
1102 unignore
1104 Removes the header field names from the list of ignored fields.
1105 unjunk Takes a message list and undoes the effect of a junk command
1107 that was previously applied on exactly these messages.
1108 unkill Takes a message list and `unkills' each message. Also sets the
1110 score of the messages to 0.
1111 Unread Same as unread.
1113 unread (U) Takes a message list and marks each message as not having
1115 been read.
1116 unretain
1118 Removes the header field names from the list of retained fields.
1119 unsaveignore
1121 Removes the header field names from the list of ignored fields
1122 for saving.
1123 unsaveretain
1125 Removes the header field names from the list of retained fields
1126 for saving.
1127 unset Takes a list of option names and discards their remembered val‐
1129 ues; the inverse of set.
1130 unshortcut
1132 Deletes the shortcut names given as arguments.
1133 unsort Disable sorted or threaded mode (see the sort and thread com‐
1135 mands), return to normal message order and, if the header vari‐
1136 able is set, print a header summary.
1137 unthread
1139 (unth) Same as unsort.
1140 verify (verif) Takes a message list and verifies each message. If a
1142 message is not an S/MIME signed message, verification will fail
1143 for it. The verification process checks if the message was
1144 signed using a valid certificate, if the message sender's email
1145 address matches one of those contained within the certificate,
1146 and if the message content has been altered.
1147 visual (v) Takes a message list and invokes the display editor on each
1149 message. Modified contents are discarded unless the write‐
1150 backedited variable is set.
1151 write (w) For conventional messages, the body without all headers is
1153 written. The output is decrypted and converted to its native
1154 format, if necessary. If the output file exists, the text is
1155 appended.—If a message is in MIME multipart format, its first
1156 part is written to the specified file as for conventional mes‐
1157 sages, and the user is asked for a filename to save each other
1158 part; if the contents of the first part are not to be saved,
1159 `write /dev/null' can be used. For the second and subsequent
1160 parts, if the filename given starts with a `|' character, the
1161 part is piped through the remainder of the filename interpreted
1162 as a shell command. In non-interactive mode, only the parts of
1163 the multipart message that have a filename given in the part
1164 header are written, the other are discarded. The original mes‐
1165 sage is never marked for deletion in the originating mail
1166 folder. For attachments, the contents of the destination file
1167 are overwritten if the file previously existed. No special han‐
1168 dling of compressed files is performed.
1169 xit (x) A synonym for exit.
1171 z Nail presents message headers in windowfuls as described under
1173 the headers command. The z command scrolls to the next window
1174 of messages. If an argument is given, it specifies the window
1175 to use. A number prefixed by `+' or `-' indicates that the win‐
1176 dow is calculated in relation to the current position. A number
1177 without a prefix specifies an absolute window number, and a `$'
1178 lets nail scroll to the last window of messages.
1179 Z Similar to z, but scrolls to the next or previous window that
1181 contains at least one new or `flagged' message.
1182 Tilde escapes
1184 Here is a summary of the tilde escapes, which are used when composing
1185 messages to perform special functions. Tilde escapes are only recog‐
1186 nized at the beginning of lines. The name `tilde escape' is somewhat
1187 of a misnomer since the actual escape character can be set by the
1188 option escape.
1189 ~!command
1191 Execute the indicated shell command, then return to the message.
1192 ~. Same effect as typing the end-of-file character.
1194 ~<filename
1196 Identical to ~r.
1197 ~<!command
1199 Command is executed using the shell. Its standard output is
1200 inserted into the message.
1201 ~@ [filename . . . ]
1203 With no arguments, edit the attachment list. First, the user
1204 can edit all existing attachment data. If an attachment's file
1205 name is left empty, that attachment is deleted from the list.
1206 When the end of the attachment list is reached, nail will ask
1207 for further attachments, until an empty file name is given. If
1208 filename arguments are specified, all of them are appended to
1209 the end of the attachment list. Filenames which contain white
1210 space can only be specified with the first method (no filename
1211 arguments).
1212 ~A Inserts the string contained in the Sign variable (same as `~i
1214 Sign'). The escape sequences `\t' (tabulator) and `\n' (new‐
1215 line) are understood.
1216 ~a Inserts the string contained in the sign variable (same as `~i
1218 sign'). The escape sequences `\t' (tabulator) and `\n' (new‐
1219 line) are understood.
1220 ~bname . . .
1222 Add the given names to the list of carbon copy recipients but do
1223 not make the names visible in the Cc: line (`blind' carbon
1224 copy).
1225 ~cname . . .
1227 Add the given names to the list of carbon copy recipients.
1228 ~d Read the file `dead.letter' from the user's home directory into
1230 the message.
1231 ~e Invoke the text editor on the message collected so far. After
1233 the editing session is finished, the user may continue appending
1234 text to the message.
1235 ~fmessages
1237 Read the named messages into the message being sent. If no mes‐
1238 sages are specified, read in the current message. Message head‐
1239 ers currently being ignored (by the ignore or retain command)
1240 are not included. For MIME multipart messages, only the first
1241 printable part is included.
1242 ~Fmessages
1244 Identical to ~f, except all message headers and all MIME parts
1245 are included.
1246 ~h Edit the message header fields `To:', `Cc:', `Bcc:', and `Sub‐
1248 ject:' by typing each one in turn and allowing the user to
1249 append text to the end or modify the field by using the current
1250 terminal erase and kill characters.
1251 ~H Edit the message header fields `From:', `Reply-To:', `Sender:',
1253 and `Organization:' in the same manner as described for ~h. The
1254 default values for these fields originate from the from,
1255 replyto, and ORGANIZATION variables. If this tilde command has
1256 been used, changing the variables has no effect on the current
1257 message anymore.
1258 ~ivariable
1260 Insert the value of the specified variable into the message
1261 adding a newline character at the end. If the variable is unset
1262 or empty, the message remains unaltered. The escape sequences
1263 `\t' (tabulator) and `\n' (newline) are understood.
1264 ~mmessages
1266 Read the named messages into the message being sent, indented by
1267 a tab or by the value of indentprefix. If no messages are spec‐
1268 ified, read the current message. Message headers currently
1269 being ignored (by the ignore or retain command) are not
1270 included. For MIME multipart messages, only the first printable
1271 part is included.
1272 ~Mmessages
1274 Identical to ~m, except all message headers and all MIME parts
1275 are included.
1276 ~p Print out the message collected so far, prefaced by the message
1278 header fields and followed by the attachment list, if any. If
1279 the message text is longer than the screen size, it is piped
1280 through the pager.
1281 ~q Abort the message being sent, copying the message to `dead.let‐
1283 ter' in the user's home directory if save is set.
1284 ~rfilename
1286 Read the named file into the message.
1287 ~sstring
1289 Cause the named string to become the current subject field.
1290 ~tname . . .
1292 Add the given names to the direct recipient list.
1293 ~v Invoke an alternate editor (defined by the VISUAL option) on the
1295 message collected so far. Usually, the alternate editor will be
1296 a screen editor. After the editor is quit, the user may resume
1297 appending text to the end of the message.
1298 ~wfilename
1300 Write the message onto the named file. If the file exists, the
1301 message is appended to it.
1302 ~x Same as ~q, except that the message is not saved to the
1304 `dead.letter' file.
1305 ~|command
1307 Pipe the message through the command as a filter. If the com‐
1308 mand gives no output or terminates abnormally, retain the origi‐
1309 nal text of the message. The command fmt(1) is often used as
1310 command to rejustify the message.
1311 ~:nail-command
1313 Execute the given nail command. Not all commands, however, are
1314 allowed.
1315 ~_nail-command
1317 Identical to ~:.
1318 ~~string
1320 Insert the string of text in the message prefaced by a single ~.
1321 If the escape character has been changed, that character must be
1322 doubled in order to send it at the beginning of a line.
1323 Variable options
1325 Options are controlled via set and unset commands, see their entries
1326 for a syntax description. An option is also set if it is passed to
1327 nail as part of the environment (this is not restricted to specific
1328 variables as in the POSIX standard). A value given in a startup file
1329 overrides a value imported from the environment. Options may be either
1330 binary, in which case it is only significant to see whether they are
1331 set or not; or string, in which case the actual value is of interest.
1332 Binary options
1334 The binary options include the following:
1335 allnet Causes only the local part to be evaluated when comparing
1337 addresses.
1338 append Causes messages saved in mbox to be appended to the end rather
1340 than prepended. This should always be set.
1341 ask or asksub
1343 Causes nail to prompt for the subject of each message sent. If
1344 the user responds with simply a newline, no subject field will
1345 be sent.
1346 askatend
1348 Causes the prompts for `Cc:' and `Bcc:' lists to appear after
1349 the message has been edited.
1350 askattach
1352 If set, nail asks for files to attach at the end of each mes‐
1353 sage. Responding with a newline indicates not to include an
1354 attachment.
1355 askcc Causes the user to be prompted for additional carbon copy recip‐
1357 ients (at the end of each message if askatend or bsdcompat is
1358 set). Responding with a newline indicates the user's satisfac‐
1359 tion with the current list.
1360 askbcc Causes the user to be prompted for additional blind carbon copy
1362 recipients (at the end of each message if askatend or bsdcompat
1363 is set). Responding with a newline indicates the user's satis‐
1364 faction with the current list.
1365 asksign
1367 Causes the user to be prompted if the message is to be signed at
1368 the end of each message. The smime-sign variable is ignored
1369 when this variable is set.
1370 autocollapse
1372 Causes threads to be collapsed automatically when threaded mode
1373 is entered (see the collapse command).
1374 autoinc
1376 Same as newmail.
1377 autoprint
1379 Causes the delete command to behave like dp - thus, after delet‐
1380 ing a message, the next one will be typed automatically.
1381 autothread
1383 Causes threaded mode (see the thread command) to be entered
1384 automatically when a folder is opened.
1385 bang Enables the substitution of `!' by the contents of the last
1387 command line in shell escapes.
1388 bsdannounce
1390 Causes automatic display of a header summary after executing a
1391 folder command.
1392 bsdcompat
1394 Sets some cosmetical features to traditional BSD style; has the
1395 same affect as setting `askatend' and all other variables pre‐
1396 fixed with `bsd', setting prompt to `& ', and changing the
1397 default pager to more.
1398 bsdflags
1400 Changes the letters printed in the first column of a header sum‐
1401 mary to traditional BSD style.
1402 bsdheadline
1404 Changes the display of columns in a header summary to tradi‐
1405 tional BSD style.
1406 bsdmsgs
1408 Changes some informational messages to traditional BSD style.
1409 bsdorder
1411 Causes the `Subject:' field to appear immediately after the
1412 `To:' field in message headers and with the ~h tilde command.
1413 bsdset Changes the output format of the set command to traditional BSD
1415 style.
1416 chained-junk-tokens
1418 Normally, the Bayesian junk mail filter bases its classifica‐
1419 tions on single word tokens extracted from messages. If this
1420 option is set, adjacent words are combined to pairs, which are
1421 then used as additional tokens. This usually improves the accu‐
1422 racy of the filter, but also increases the junk mail database
1423 five- to tenfold.
1424 datefield
1426 The date in a header summary is normally the date of the mailbox
1427 `From ' line of the message. If this variable is set, the date
1428 as given in the `Date:' header field is used, converted to local
1429 time.
1430 debug Prints debugging messages and disables the actual delivery of
1432 messages. Unlike verbose, this option is intended for nail
1433 development only.
1434 disconnected
1436 When an IMAP mailbox is selected and this variable is set, no
1437 connection to the server is initiated. Instead, data is
1438 obtained from the local cache (see imap-cache). Mailboxes that
1439 are not present in the cache and messages that have not yet
1440 entirely been fetched from the server are not available; to
1441 fetch all messages in a mailbox at once, the command `copy *
1442 /dev/null' can be used while still in online mode. Changes that
1443 are made to IMAP mailboxes in disconnected mode are queued and
1444 committed later when a connection to that server is opened in
1445 online mode. This procedure is not completely reliable since it
1446 cannot be guaranteed that the IMAP unique identifiers (UIDs) on
1447 the server still match the ones in the cache at that time. Data
1448 is saved to `dead.letter' when this problem occurs.
1449 disconnected-user@host
1451 The specified account is handled as described for the discon‐
1452 nected variable above, but other accounts are not affected.
1453 dot The binary option dot causes nail to interpret a period alone on
1455 a line as the terminator of a message the user is sending.
1456 editheaders
1458 When a message is edited while being composed, its header is
1459 included in the editable text. `To:', `Cc:', `Bcc:', `Sub‐
1460 ject:', `From:', `Reply-To:', `Sender:', and 'Organization:'
1461 fields are accepted within the header, other fields are ignored.
1462 emptybox
1464 If set, an empty mailbox file is not removed. This may improve
1465 the interoperability with other mail user agents when using a
1466 common folder directory.
1467 emptystart
1469 If the mailbox is empty, nail normally prints `No mail for user'
1470 and exits immediately. If this option is set, nail starts even
1471 with an empty mailbox.
1472 flipr Exchanges the Respond with the respond commands and vice-versa.
1474 forward-as-attachment
1476 Original messages are normally sent as inline text with the for‐
1477 ward command, and only the first part of a multipart message is
1478 included. With this option, messages are sent as MIME mes‐
1479 sage/rfc822 attachments, and all of their parts are included.
1480 The fwdignore and fwdretain options are ignored when the for‐
1481 ward-as-attachment option is set.
1482 fullnames
1484 When replying to a message, nail normally removes the comment
1485 parts of email addresses, which by convention contain the full
1486 names of the recipients. If this variable is set, such strip‐
1487 ping is not performed, and comments are retained.
1488 header Causes the header summary to be written at startup and after
1490 commands that affect the number of messages or the order of mes‐
1491 sages in the current folder; enabled by default.
1492 hold This option is used to hold messages in the system mailbox by
1494 default.
1495 ignore Causes interrupt signals from the terminal to be ignored and
1497 echoed as @'s.
1498 ignoreeof
1500 An option related to dot is ignoreeof which makes nail refuse to
1501 accept a control-d as the end of a message. Ignoreeof also
1502 applies to nail command mode.
1503 imap-use-starttls
1505 Causes nail to issue a STARTTLS command to make an unencrypted
1506 IMAP session SSL/TLS encrypted. This functionality is not sup‐
1507 ported by all servers, and is not used if the session is already
1508 encrypted by the IMAPS method.
1509 imap-use-starttls-user@host
1511 Activates imap-use-starttls for a specific account.
1512 keep This option causes nail to truncate the user's system mailbox
1514 instead of deleting it when it is empty. This should always be
1515 set, since it prevents malicious users from creating fake mail
1516 folders in a world-writable spool directory.
1517 keepsave
1519 When a message is saved, it is usually discarded from the origi‐
1520 nating folder when nail is quit. Setting this option causes all
1521 saved message to be retained.
1522 markanswered
1524 When a message is replied to and this variable is set, it is
1525 marked as having been answered. This mark has no technical
1526 meaning in the mail system; it just causes messages to be marked
1527 in the header summary, and makes them specially addressable.
1528 metoo Usually, when a group is expanded that contains the sender, the
1530 sender is removed from the expansion. Setting this option
1531 causes the sender to be included in the group.
1532 newmail
1534 Checks for new mail in the current folder each time the prompt
1535 is printed. For IMAP mailboxes, the server is then polled for
1536 new mail, which may result in delayed operation if the connec‐
1537 tion to the server is slow. A maildir folder must be re-scanned
1538 to determine if new mail has arrived.
1539 If this variable is set to the special value nopoll, an IMAP
1541 server is not actively asked for new mail, but new mail may
1542 still be detected and announced with any other IMAP command that
1543 is sent to the server. A maildir folder is not scanned then.
1544 In any case, the IMAP server may send notifications about mes‐
1546 sages that have been deleted on the server by another process or
1547 client. In this case, `Expunged n messages' is printed regard‐
1548 less of this variable, and message numbers may have changed.
1549 noheader
1551 Setting the option noheader is the same as giving the -N flag on
1552 the command line.
1553 outfolder
1555 Causes the filename given in the record variable and the sender-
1556 based filenames for the Copy and Save commands to be interpreted
1557 relative to the directory given in the folder variable rather
1558 than to the current directory unless it is an absolute pathname.
1559 page If set, each message the pipe command prints out is followed by
1561 a formfeed character.
1562 piperaw
1564 Send messages to the pipe command without performing MIME and
1565 character set conversions.
1566 pop3-use-apop
1568 If this variable is set, the APOP authentication method is used
1569 when a connection to a POP3 server is initiated. The advantage
1570 of this method over the usual USER/PASS authentication is that
1571 the password is not sent over the network in clear text. The
1572 connection fails if the server does not support the APOP com‐
1573 mand.
1574 pop3-use-apop-user@host
1576 Enables pop3-use-apop for a specific account.
1577 pop3-use-starttls
1579 Causes nail to issue a STLS command to make an unencrypted POP3
1580 session SSL/TLS encrypted. This functionality is not supported
1581 by all servers, and is not used if the session is already
1582 encrypted by the POP3S method.
1583 pop3-use-starttls-user@host
1585 Activates pop3-use-starttls for a specific account.
1586 print-all-chars
1588 This option causes all characters to be considered printable.
1589 It is only effective if given in a startup file. With this
1590 option set, some character sequences in messages may put the
1591 user's terminal in an undefined state when printed; it should
1592 only be used as a last resort if no working system locale can be
1593 found.
1594 print-alternatives
1596 When a MIME message part of type multipart/alternative is dis‐
1597 played and it contains a subpart of type text/plain, other parts
1598 are normally discarded. Setting this variable causes all sub‐
1599 parts to be displayed, just as if the surrounding part was of
1600 type multipart/mixed.
1601 quiet Suppresses the printing of the version when first invoked.
1603 record-resent
1605 If both this variable and the record variable are set, the
1606 resend and Resend commands save messages to the record folder as
1607 it is normally only done for newly composed messages.
1608 reply-in-same-charset
1610 If this variable is set, nail first tries to use the same char‐
1611 acter set of the original message for replies. If this fails,
1612 the sendcharsets variable is evaluated as usual.
1613 Replyall
1615 Reverses the sense of reply and Reply commands.
1616 save When the user aborts a message with two RUBOUT (interrupt char‐
1618 acters) nail copies the partial letter to the file `dead.letter'
1619 in the home directory. This option is set by default.
1620 searchheaders
1622 If this option is set, then a message-list specifier in the form
1623 `/x:y' will expand to all messages containing the substring `y'
1624 in the header field `x'. The string search is case insensitive.
1625 sendwait
1627 When sending a message, wait until the mail transfer agent exits
1628 before accepting further commands. If the mail transfer agent
1629 returns a non-zero exit status, the exit status of nail will
1630 also be non-zero.
1631 showlast
1633 Setting this option causes nail to start at the last message
1634 instead of the first one when opening a mail folder.
1635 showname
1637 Causes nail to use the sender's real name instead of the plain
1638 address in the header field summary and in message specifica‐
1639 tions.
1640 showto Causes the recipient of the message to be shown in the header
1642 summary if the message was sent by the user.
1643 smime-force-encryption
1645 Causes nail to refuse sending unencrypted messages.
1646 smime-sign
1648 If this variable is set, outgoing messages are S/MIME signed
1649 with the user's private key. Signing a message enables a recip‐
1650 ient to verify that the sender used a valid certificate, that
1651 the email addresses in the certificate match those in the mes‐
1652 sage header, and that the message content has not been altered.
1653 It does not change the message text, and people will be able to
1654 read the message as usual.
1655 smime-no-default-ca
1657 Do not load the default CA locations when verifying S/MIME
1658 signed messages. Only applicable if S/MIME support is built
1659 using OpenSSL.
1660 smtp-use-starttls
1662 Causes nail to issue a STARTTLS command to make an SMTP session
1663 SSL/TLS encrypted. Not all servers support this command;
1664 because of common implementation defects, it cannot be automati‐
1665 cally determined whether a server supports it or not.
1666 ssl-no-default-ca
1668 Do not load the default CA locations to verify SSL/TLS server
1669 certificates. Only applicable if SSL/TLS support is built using
1670 OpenSSL.
1671 ssl-v2-allow
1673 Accept SSLv2 connections. These are normally not allowed
1674 because this protocol version is insecure.
1675 stealthmua
1677 Inhibits the generation of the `Message-Id:' and `User-Agent:'
1678 header fields that include obvious references to nail. There
1679 are two pitfalls associated with this: First, the message id of
1680 outgoing messages is not known anymore. Second, an expert may
1681 still use the remaining information in the header to track down
1682 the originating mail user agent.
1683 verbose
1685 Setting the option verbose is the same as using the -v flag on
1686 the command line. When nail runs in verbose mode, details of
1687 the actual message delivery and protocol conversations for IMAP,
1688 POP3, and SMTP, as well as of other internal processes, are dis‐
1689 played on the user's terminal, This is sometimes useful to debug
1690 problems. Nail prints all data that is sent to remote servers
1691 in clear texts, including passwords, so care should be taken
1692 that no unauthorized option can view the screen if this option
1693 is enabled.
1694 writebackedited
1696 If this variable is set, messages modified using the edit or
1697 visual commands are written back to the current folder when it
1698 is quit. This is only possible for writable folders in mbox
1699 format. Setting this variable also disables MIME decoding and
1700 decryption for the editing commands.
1701 String Options
1703 The string options include the following:
1704 attrlist
1706 A sequence of characters to print in the `attribute' column of a
1707 header summary, each for one type of messages in the following
1708 order: new, unread but old, new but read, read and old, saved,
1709 preserved, mboxed, flagged, answered, draft, killed, start of a
1710 collapsed thread, collapsed, classified as junk. The default is
1711 `NUROSPMFATK+-J', or `NU *HMFATK+-J' if bsdflags or the SYSV3
1712 environment variable are set.
1713 autobcc
1715 Specifies a list of recipients to which a blind carbon copy of
1716 each outgoing message will be sent automatically.
1717 autocc Specifies a list of recipients to which a carbon copy of each
1719 outgoing message will be sent automatically.
1720 autosort
1722 Causes sorted mode (see the sort command) to be entered automat‐
1723 ically with the value of this option as sorting method when a
1724 folder is opened.
1725 cmd The default value for the pipe command.
1727 crt The valued option crt is used as a threshold to determine how
1729 long a message must be before PAGER is used to read it. If crt
1730 is set without a value, then the height of the terminal screen
1731 stored in the system is used to compute the threshold (see
1732 stty(1)).
1733 DEAD The name of the file to use for saving aborted messages. This
1735 defaults to `dead.letter' in the user's home directory.
1736 EDITOR Pathname of the text editor to use in the edit command and ~e
1738 escape. If not defined, then a default editor is used.
1739 encoding
1741 The default MIME encoding to use in outgoing text messages and
1742 message parts. Valid values are 8bit or quoted-printable. The
1743 default is 8bit. In case the mail transfer system is not ESMTP
1744 compliant, quoted-printable should be used instead. If there is
1745 no need to encode a message, 7bit transfer mode is used, without
1746 regard to the value of this variable. Binary data is always
1747 encoded in base64 mode.
1748 escape If defined, the first character of this option gives the charac‐
1750 ter to use in the place of ~ to denote escapes.
1751 folder The name of the directory to use for storing folders of mes‐
1753 sages. All folder names that begin with `+' refer to files
1754 below that directory. If the directory name begins with a `/',
1755 nail considers it to be an absolute pathname; otherwise, the
1756 folder directory is found relative to the user's home directory.
1757 The directory name may also refer to an IMAP account; any names
1759 that begin with `+' then refer to IMAP mailboxes on that
1760 account. An IMAP folder is normally given in the form
1761 imaps://mylogin@imap.myisp.example
1763 In this case, the `+' and `@' prefixes for folder names have the
1765 same effect (see the folder command).
1766 Some IMAP servers do not accept the creation of mailboxes in the
1768 hierarchy base; they require that they are created as subfolders
1769 of `INBOX'. With such servers, a folder name of the form
1770 imaps://mylogin@imap.myisp.example/INBOX.
1772 should be used (the last character is the server's hierarchy
1774 delimiter). Folder names prefixed by `+' will then refer to
1775 folders below `INBOX', while folder names prefixed by `@' refer
1776 to folders below the hierarchy base. See the imap namespace
1777 command for a method to detect the appropriate prefix and delim‐
1778 iter.
1779 folder-hook
1781 When a folder is opened and this variable is set, the macro cor‐
1782 responding to the value of this variable is executed. The macro
1783 is also invoked when new mail arrives, but message lists for
1784 commands executed from the macro only include newly arrived mes‐
1785 sages then.
1786 folder-hook-fullname
1788 When a folder named fullname is opened, the macro corresponding
1789 to the value of this variable is executed. Unlike other folder
1790 specifications, the fully expanded name of a folder, without
1791 metacharacters, is used to avoid ambiguities. The macro speci‐
1792 fied with folder-hook is not executed if this variable is effec‐
1793 tive for a folder (unless it is explicitly invoked within the
1794 called macro).
1795 from The address (or a list of addresses) to put into the `From:'
1797 field of the message header. If replying to a message, these
1798 addresses are handled as if they were in the alternates list.
1799 If the machine's hostname is not valid at the Internet (for
1800 example at a dialup machine), either this variable or hostname
1801 have to be set to get correct Message-ID header fields. If from
1802 contains more than one address, the sender variable must also be
1803 set.
1804 fwdheading
1806 The string to print before the text of a message with the for‐
1807 ward command (unless the forward-as-attachment variable is set).
1808 Defaults to ``-------- Original Message --------'' if unset. If
1809 it is set to the empty string, no heading is printed.
1810 headline
1812 A format string to use for the header summary, similar to printf
1813 formats. A `%' character introduces a format specifier. It may
1814 be followed by a number indicating the field width. If the
1815 field is a number, the width may be negative, which indicates
1816 that it is to be left-aligned. Valid format specifiers are:
1817 %a Message attributes.
1820 %c The score of the message.
1821 %d The date when the message was received.
1822 %e The indenting level in threaded mode.
1823 %f The address of the message sender.
1824 %i The message thread structure.
1825 %l The number of lines of the message.
1826 %m Message number.
1827 %o The number of octets (bytes) in the message.
1828 %s Message subject (if any).
1829 %S Message subject (if any) in double quotes.
1830 %t The position in threaded/sorted order.
1831 %> A `>' for the current message, otherwise ` '.
1832 %< A `<' for the current message, otherwise ` '.
1833 %% A `%' character.
1834 The default is `%>%a%m %18f %16d %4l/%-5o %i%s', or
1836 `%>%a%m %20f %16d %3l/%-5o %i%S' if bsdcompat is set.
1837 hostname
1839 Use this string as hostname when expanding local addresses
1840 instead of the value obtained from uname(2) and getaddrinfo(3).
1841 imap-auth
1843 Sets the IMAP authentication method. Valid values are `login'
1844 for the usual password-based authentication (the default),
1845 `cram-md5', which is a password-based authentication that does
1846 not send the password over the network in clear text, and `gss‐
1847 api' for GSSAPI-based authentication.
1848 imap-auth-user@host
1850 Sets the IMAP authentication method for a specific account.
1851 imap-cache
1853 Enables caching of IMAP mailboxes. The value of this variable
1854 must point to a directory that is either existent or can be cre‐
1855 ated by nail. All contents of the cache can be deleted by nail
1856 at any time; it is not safe to make assumptions about them.
1857 imap-keepalive
1859 IMAP servers may close the connection after a period of inactiv‐
1860 ity; the standard requires this to be at least 30 minutes, but
1861 practical experience may vary. Setting this variable to a
1862 numeric value greater than 0 causes a NOOP command to be sent
1863 each value seconds if no other operation is performed.
1864 imap-list-depth
1866 When retrieving the list of folders on an IMAP server, the fold‐
1867 ers command stops after it has reached a certain depth to avoid
1868 possible infinite loops. The value of this variable sets the
1869 maximum depth allowed. The default is 2. If the folder separa‐
1870 tor on the current IMAP server is a slash `/', this variable has
1871 no effect, and the folders command does not descend to subfold‐
1872 ers.
1873 indentprefix
1875 String used by the `~m' and `~M' tilde escapes and by the quote
1876 option for indenting messages, in place of the normal tab char‐
1877 acter (^I). Be sure to quote the value if it contains spaces or
1878 tabs.
1879 junkdb The location of the junk mail database. The string is treated
1881 like a folder name, as described for the folder command.
1882 The files in the junk mail database are normally stored in com‐
1884 press(1) format for saving space. If processing time is consid‐
1885 ered more important, uncompress(1) can be used to store them in
1886 plain form. Nail will then work using the uncompressed files.
1887 LISTER Pathname of the directory lister to use in the folders command
1889 when operating on local mailboxes. Default is /bin/ls.
1890 MAIL Is used as the user's mailbox, if set. Otherwise, a system-
1892 dependent default is used. Can be a protocol:// string (see the
1893 folder command for more information).
1894 MAILX_HEAD
1896 A string to put at the beginning of each new message. The
1897 escape sequences `\t' (tabulator) and `\n' (newline) are under‐
1898 stood.
1899 MAILX_TAIL
1901 A string to put at the end of each new message. The escape
1902 sequences `\t' (tabulator) and `\n' (newline) are understood.
1903 maximum-unencoded-line-length
1905 Messages that contain lines longer than the value of this vari‐
1906 able are encoded in quoted-printable even if they contain only
1907 ASCII characters. The maximum effective value is 950. If set
1908 to 0, all ASCII text messages are encoded in quoted-printable.
1909 S/MIME signed messages are always encoded in quoted-printable
1910 regardless of the value of this variable.
1911 MBOX The name of the mbox file. It can be the name of a folder. The
1913 default is `mbox' in the user's home directory.
1914 NAIL_EXTRA_RC
1916 The name of an optional startup file to be read after ~/.mailrc.
1917 This variable is ignored if it is imported from the environment;
1918 it has an effect only if it is set in /etc/nail.rc or ~/.mailrc
1919 to allow bypassing the configuration with e. g.
1920 `MAILRC=/dev/null'. Use this file for commands that are not
1921 understood by other nail implementations.
1922 newfolders
1924 If this variable has the value maildir, newly created local
1925 folders will be in maildir format.
1926 nss-config-dir
1928 A directory that contains the files certN.db to retrieve cer‐
1929 tificates, keyN.db to retrieve private keys, and secmod.db,
1930 where N is a digit. These are usually taken from Mozilla
1931 installations, so an appropriate value might be
1932 `~/.mozilla/firefox/default.clm'. Nail opens these files read-
1933 only and does not modify them. However, if the files are modi‐
1934 fied by Mozilla while nail is running, it will print a `Bad
1935 database' message. It may be necessary to create copies of
1936 these files that are exclusively used by nail then. Only appli‐
1937 cable if S/MIME and SSL/TLS support is built using Network Secu‐
1938 rity Services (NSS).
1939 ORGANIZATION
1941 The value to put into the `Organization:' field of the message
1942 header.
1943 PAGER Pathname of the program to use in the more command or when crt
1945 variable is set. The default paginator pg(1) or, in BSD compat‐
1946 ibility mode, more(1) is used if this option is not defined.
1947 password-user@host
1949 Set the password for user when connecting to host. If no such
1950 variable is defined for a host, the user will be asked for a
1951 password on standard input. Specifying passwords in a startup
1952 file is generally a security risk, the file should be readable
1953 by the invoking user only.
1954 pipe-content/subcontent
1956 When a MIME message part of content/subcontent type is displayed
1957 or it is replied to, its text is filtered through the value of
1958 this variable interpreted as a shell command. Special care must
1959 be taken when using such commands as mail viruses may be dis‐
1960 tributed by this method; if messages of type application/x-sh
1961 were filtered through the shell, for example, a message sender
1962 could easily execute arbitrary code on the system nail is run‐
1963 ning on.
1964 pop3-keepalive
1966 POP3 servers may close the connection after a period of inactiv‐
1967 ity; the standard requires this to be at least 10 minutes, but
1968 practical experience may vary. Setting this variable to a
1969 numeric value greater than 0 causes a NOOP command to be sent
1970 each value seconds if no other operation is performed.
1971 prompt The string printed when a command is accepted. Defaults to
1973 `? ', or to `& ' if the bsdcompat variable is set.
1974 quote If set, nail starts a replying message with the original message
1976 prefixed by the value of the variable indentprefix. Normally, a
1977 heading consisting of `Fromheaderfield wrote:' is printed before
1978 the quotation. If the string noheading is assigned to the quote
1979 variable, this heading is omitted. If the string headers is
1980 assigned, the headers selected by the ignore/retain commands are
1981 printed above the message body, thus quote acts like an auto‐
1982 matic ~m command then. If the string allheaders is assigned,
1983 all headers are printed above the message body, and all MIME
1984 parts are included, thus quote acts like an automatic ~M command
1985 then.
1986 record If defined, gives the pathname of the folder used to record all
1988 outgoing mail. If not defined, then outgoing mail is not so
1989 saved. When saving to this folder fails, the message is not
1990 sent but saved to the `dead.letter' file instead.
1991 replyto
1993 A list of addresses to put into the `Reply-To:' field of the
1994 message header. If replying to a message, such addresses are
1995 handled as if they were in the alternates list.
1996 screen When nail initially prints the message headers, it determines
1998 the number to print by looking at the speed of the terminal.
1999 The faster the terminal, the more it prints. This option over‐
2000 rides this calculation and specifies how many message headers
2001 are printed. This number is also used for scrolling with the z
2002 command.
2003 sendcharsets
2005 A comma-separated list of character set names that can be used
2006 in Internet mail. When a message that contains characters not
2007 representable in US-ASCII is prepared for sending, nail tries to
2008 convert its text to each of the given character sets in order
2009 and uses the first appropriate one. The default is `utf-8'.
2010 Character sets assigned to this variable should be ordered in
2012 ascending complexity. That is, the list should start with e.g.
2013 `iso-8859-1' for compatibility with older mail clients, might
2014 contain some other language-specific character sets, and should
2015 end with `utf-8' to handle messages that combine texts in multi‐
2016 ple languages.
2017 sender An address that is put into the `Sender:' field of outgoing mes‐
2019 sages. This field needs not normally be present. It is, how‐
2020 ever, required if the `From:' field contains more than one
2021 address. It can also be used to indicate that a message was
2022 sent on behalf of somebody other; in this case, `From:' should
2023 contain the address of the person that took responsibility for
2024 the message, and `Sender:' should contain the address of the
2025 person that actually sent the message. The sender address is
2026 handled as if it were in the alternates list.
2027 sendmail
2029 To use an alternate mail delivery system, set this option to the
2030 full pathname of the program to use. This should be used with
2031 care.
2032 SHELL Pathname of the shell to use in the ! command and the ~! escape.
2034 A default shell is used if this option is not defined.
2035 Sign A string for use with the ~A command.
2038 sign A string for use with the ~a command.
2040 signature
2042 Must correspond to the name of a readable file if set.
2043 The file's content is then appended to each singlepart
2044 message and to the first part of each multipart message.
2045 Be warned that there is no possibility to edit the signa‐
2046 ture for an individual message.
2047 smime-ca-dir
2049 Specifies a directory with CA certificates for verifica‐
2050 tion of S/MIME signed messages. The format is the same
2051 as described in SSL_CTX_load_verify_locations(3). Only
2052 applicable if S/MIME support is built using OpenSSL.
2053 smime-ca-file
2055 Specifies a file with CA certificates for verification of
2056 S/MIME signed messages. The format is the same as
2057 described in SSL_CTX_load_verify_locations(3). Only
2058 applicable if S/MIME support is built using OpenSSL.
2059 smime-cipher-user@host
2061 Specifies a cipher to use when generating S/MIME
2062 encrypted messages for user@host. Valid ciphers are
2063 rc2-40 (RC2 with 40 bits), rc2-64 (RC2 with 64 bits), des
2064 (DES, 56 bits) and des-ede3 (3DES, 112/168 bits). The
2065 default is 3DES. It is not recommended to use the other
2066 ciphers unless a recipient's client is actually unable to
2067 handle 3DES since they are comparatively weak; but even
2068 so, the recipient should upgrade his software in prefer‐
2069 ence.
2070 smime-crl-file
2072 Specifies a file that contains a CRL in PEM format to use
2073 when verifying S/MIME messages. Only applicable if
2074 S/MIME support is built using OpenSSL.
2075 smime-crl-dir
2077 Specifies a directory that contains files with CRLs in
2078 PEM format to use when verifying S/MIME messages. Only
2079 applicable if S/MIME support is built using OpenSSL.
2080 smime-encrypt-user@host
2082 If this variable is set, messages to user@host are
2083 encrypted before sending. If S/MIME support is built
2084 using OpenSSL, the value of the variable must be set to
2085 the name of a file that contains a certificate in PEM
2086 format. If S/MIME support is built using NSS, the value
2087 of this variable is ignored, but if multiple certificates
2088 for user@host are available, the smime-nickname-user@host
2089 variable should be set. Otherwise a certificate for the
2090 recipient is automatically retrieved from the certificate
2091 database, if possible.
2092 If a message is sent to multiple recipients, each of them
2094 for whom a corresponding variable is set will receive an
2095 individually encrypted message; other recipients will
2096 continue to receive the message in plain text unless the
2097 smime-force-encryption variable is set. It is recom‐
2098 mended to sign encrypted messages, i.e. to also set the
2099 smime-sign variable.
2100 smime-nickname-user@host
2102 Specifies the nickname of a certificate to be used when
2103 encrypting messages for user@host . Only applicable if
2104 S/MIME support is built using NSS.
2105 smime-sign-cert
2107 Points to a file in PEM format that contains the user's
2108 private key as well as his certificate. Both are used
2109 with S/MIME for signing and decrypting messages. Only
2110 applicable if S/MIME support is built using OpenSSL.
2111 smime-sign-cert-user@host
2113 Overrides smime-sign-cert for the specific addresses.
2114 When signing messages and the value of the from variable
2115 is set to user@host, the specific file is used. When
2116 decrypting messages, their recipient fields (To: and Cc:)
2117 are searched for addresses for which such a variable is
2118 set. Nail always uses the first address that matches, so
2119 if the same message is sent to more than one of the
2120 user's addresses using different encryption keys, decryp‐
2121 tion might fail. Only applicable if S/MIME support is
2122 built using OpenSSL.
2123 smime-sign-nickname
2125 Specifies that the named certificate be used for signing
2126 mail. If this variable is not set, but a single certifi‐
2127 cate matching the current from address is found in the
2128 database, that one is used automatically. Only applica‐
2129 ble if S/MIME support is built using NSS.
2130 smime-sign-nickname-user@host
2132 Overrides smime-sign-nickname for a specific address.
2133 Only applicable if S/MIME support is built using NSS.
2134 smtp Normally, nail invokes sendmail(8) directly to transfer
2136 messages. If the smtp variable is set, a SMTP connection
2137 to the server specified by the value of this variable is
2138 used instead. If the SMTP server does not use the stan‐
2139 dard port, a value of server:port can be given, with port
2140 as a name or as a number.
2141 There are two possible methods to get SSL/TLS encrypted
2143 SMTP sessions: First, the STARTTLS command can be used to
2144 encrypt a session after it has been initiated, but before
2145 any user-related data has been sent; see
2146 smtp-use-starttls above. Second, some servers accept
2147 sessions that are encrypted from their beginning on. This
2148 mode is configured by assigning smtps://server[:port] to
2149 the smtp variable.
2150 The SMTP transfer is executed in a child process; unless
2152 either the sendwait or the verbose variable is set, this
2153 process runs asynchronously. If it receives a TERM sig‐
2154 nal, it will abort and save the message to the `dead.let‐
2155 ter' file.
2156 smtp-auth
2158 Sets the SMTP authentication method. If set to `login',
2159 or if unset and smtp-auth-user is set, AUTH LOGIN is
2160 used. If set to `cram-md5', AUTH CRAM-MD5 is used. Oth‐
2161 erwise, no SMTP authentication is performed.
2162 smtp-auth-user@host
2164 Overrides smtp-auth for specific values of sender
2165 addresses, depending on the from variable.
2166 smtp-auth-password
2168 Sets the global password for SMTP AUTH. Both user and
2169 password have to be given for AUTH LOGIN and AUTH CRAM-
2170 MD5.
2171 smtp-auth-password-user@host
2173 Overrides smtp-auth-password for specific values of
2174 sender addresses, depending on the from variable.
2175 smtp-auth-user
2177 Sets the global user name for SMTP AUTH. Both user and
2178 password have to be given for AUTH LOGIN and AUTH CRAM-
2179 MD5.
2180 If this variable is set but neither smtp-auth-password or
2182 a matching smtp-auth-password-user@host can be found,
2183 nail will as for a password on the user's terminal.
2184 smtp-auth-user-user@host
2186 Overrides smtp-auth-user for specific values of sender
2187 addresses, depending on the from variable.
2188 ssl-ca-dir
2190 Specifies a directory with CA certificates for verifica‐
2191 tion of SSL/TLS server certificates. See
2192 SSL_CTX_load_verify_locations(3) for more information.
2193 Only applicable if SSL/TLS support is built using
2194 OpenSSL.
2195 ssl-ca-file
2197 Specifies a file with CA certificates for verification of
2198 SSL/TLS server certificates. See SSL_CTX_load_ver‐
2199 ify_locations(3) for more information. Only applicable
2200 if SSL/TLS support is built using OpenSSL.
2201 ssl-cert
2203 Sets the file name for a SSL/TLS client certificate
2204 required by some servers. Only applicable if SSL/TLS
2205 support is built using OpenSSL.
2206 ssl-cert-user@host
2208 Sets an account-specific file name for a SSL/TLS client
2209 certificate required by some servers. Overrides ssl-cert
2210 for the specified account. Only applicable if SSL/TLS
2211 support is built using OpenSSL.
2212 ssl-cipher-list
2214 Specifies a list of ciphers for SSL/TLS connections. See
2215 ciphers(1) for more information. Only applicable if
2216 SSL/TLS support is built using OpenSSL.
2217 ssl-crl-file
2219 Specifies a file that contains a CRL in PEM format to use
2220 when verifying SSL/TLS server certificates. Only appli‐
2221 cable if SSL/TLS support is built using OpenSSL.
2222 ssl-crl-dir
2224 Specifies a directory that contains files with CRLs in
2225 PEM format to use when verifying SSL/TLS server certifi‐
2226 cates. Only applicable if SSL/TLS support is built using
2227 OpenSSL.
2228 ssl-key
2230 Sets the file name for the private key of a SSL/TLS
2231 client certificate. If unset, the name of the certifi‐
2232 cate file is used. The file is expected to be in PEM
2233 format. Only applicable if SSL/TLS support is built
2234 using OpenSSL.
2235 ssl-key-user@host
2237 Sets an account-specific file name for the private key of
2238 a SSL/TLS client certificate. Overrides ssl-key for the
2239 specified account. Only applicable if SSL/TLS support is
2240 built using OpenSSL.
2241 ssl-method
2243 Selects a SSL/TLS protocol version; valid values are
2244 `ssl2', `ssl3', and `tls1'. If unset, the method is
2245 selected automatically, if possible.
2246 ssl-method-user@host
2248 Overrides ssl-method for a specific account.
2249 ssl-rand-egd
2251 Gives the pathname to an entropy daemon socket, see
2252 RAND_egd(3).
2253 ssl-rand-file
2255 Gives the pathname to a file with entropy data, see
2256 RAND_load_file(3). If the file is a regular file
2257 writable by the invoking user, new data is written to it
2258 after it has been loaded. Only applicable if SSL/TLS
2259 support is built using OpenSSL.
2260 ssl-verify
2262 Sets the action to be performed if an error occurs during
2263 SSL/TLS server certificate validation. Valid values are
2264 `strict' (fail and close connection immediately), `ask'
2265 (ask whether to continue on standard input), `warn'
2266 (print a warning and continue), `ignore' (do not perform
2267 validation). The default is `ask'.
2268 ssl-verify-user@host
2270 Overrides ssl-verify for a specific account.
2271 toplines
2273 If defined, gives the number of lines of a message to be
2274 printed out with the top command; normally, the first
2275 five lines are printed.
2276 ttycharset
2278 The character set of the terminal nail operates on.
2279 There is normally no need to set this variable since nail
2280 can determine this automatically by looking at the
2281 LC_CTYPE locale setting; if this succeeds, the value is
2282 assigned at startup and will be displayed by the set com‐
2283 mand. Note that this is not necessarily a character set
2284 name that can be used in Internet messages.
2285 VISUAL Pathname of the text editor to use in the visual command
2287 and ~v escape.
2288
2290 Besides the variables described above, nail uses the following
2291 environment strings:
2292 HOME The user's home directory.
2294 LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES
2296 See locale(7).
2297 MAILRC Is used as startup file instead of ~/.mailrc if set.
2299 When nail scripts are invoked on behalf of other users,
2300 this variable should be set to `/dev/null' to avoid side-
2301 effects from reading their configuration files.
2302 NAILRC If this variable is set and MAILRC is not set, it is read
2304 as startup file.
2305 SYSV3 Changes the letters printed in the first column of a
2307 header summary.
2308 TMPDIR Used as directory for temporary files instead of /tmp, if
2310 set.
2311
2313 ~/.mailrc
2314 File giving initial commands.
2315 /etc/nail.rc
2317 System wide initialization file.
2318 ~/.mime.types
2320 Personal MIME types.
2321 /etc/mime.types
2323 System wide MIME types.
2324
2326 Getting started
2327 The nail command has two distinct usages, according to whether
2328 one wants to send or receive mail. Sending mail is simple: to
2329 send a message to a user whose email address is, say,
2330 <bill@host.example>, use the shell command:
2331 $ nail bill@host.example
2333 then type your message. Nail will prompt you for a message sub‐
2335 ject first; after that, lines typed by you form the body of the
2336 message. When you reach the end of the message, type an EOT
2337 (control-d) at the beginning of a line, which will cause nail to
2338 echo `EOT' and return you to the shell.
2339 If, while you are composing the message you decide that you do
2341 not wish to send it after all, you can abort the letter with a
2342 RUBOUT. Typing a single RUBOUT causes nail to print `(Interrupt
2343 -- one more to kill letter)'. Typing a second RUBOUT causes
2344 nail to save your partial letter on the file `dead.letter' in
2345 your home directory and abort the letter. Once you have sent
2346 mail to someone, there is no way to undo the act, so be careful.
2347 If you want to send the same message to several other people,
2349 you can list their email addresses on the command line. Thus,
2350 $ nail sam@workstation.example bob@server.example
2352 Subject: Fees
2353 Tuition fees are due next Friday. Don't forget!
2354 <Control-d>
2355 EOT
2356 $
2357 will send the reminder to <sam@workstation.example>. and
2359 <bob@server.example>.
2360 To read your mail, simply type
2362 $ nail
2364 Nail will respond by typing its version number and date and then
2366 listing the messages you have waiting. Then it will type a
2367 prompt and await your command. The messages are assigned num‐
2368 bers starting with 1—you refer to the messages with these num‐
2369 bers. Nail keeps track of which messages are new (have been
2370 sent since you last read your mail) and read (have been read by
2371 you). New messages have an N next to them in the header listing
2372 and old, but unread messages have a U next to them. Nail keeps
2373 track of new/old and read/unread messages by putting a header
2374 field called Status into your messages.
2375 To look at a specific message, use the type command, which may
2377 be abbreviated to simply t . For example, if you had the fol‐
2378 lowing messages:
2379 O 1 drfoo@myhost.example Wed Sep 1 19:52 18/631 "Fees"
2381 O 2 sam@friends.example Thu Sep 2 00:08 30/895
2382 you could examine the first message by giving the command:
2384 type 1
2386 which might cause to respond with, for example:
2388 Message 1:
2390 From drfoo@myhost.example Wed Sep 1 19:52:25 2004
2391 Subject: Fees
2392 Status: R
2393 Tuition fees are due next Wednesday. Don't forget!
2395 Many nail commands that operate on messages take a message num‐
2398 ber as an argument like the type command. For these commands,
2399 there is a notion of a current message. When you enter the nail
2400 program, the current message is initially the first (or the
2401 first recent) one. Thus, you can often omit the message number
2402 and use, for example,
2403 t
2405 to type the current message. As a further shorthand, you can
2407 type a message by simply giving its message number. Hence,
2408 1
2410 would type the first message.
2412 Frequently, it is useful to read the messages in your mailbox in
2414 order, one after another. You can read the next message in nail
2415 by simply typing a newline. As a special case, you can type a
2416 newline as your first command to nail to type the first message.
2417 If, after typing a message, you wish to immediately send a
2419 reply, you can do so with the reply command. This command, like
2420 type, takes a message number as an argument. nail then begins a
2421 message addressed to the user who sent you the message. You may
2422 then type in your letter in reply, followed by a <control-d> at
2423 the beginning of a line, as before.
2424 Note that nail copies the subject header from the original mes‐
2426 sage. This is useful in that correspondence about a particular
2427 matter will tend to retain the same subject heading, making it
2428 easy to recognize. If there are other header fields in the mes‐
2429 sage, like `Cc:', the information found will also be used.
2430 Sometimes you will receive a message that has been sent to sev‐
2432 eral people and wish to reply only to the person who sent it.
2433 Reply with a capital R replies to a message, but sends a copy to
2434 the sender only.
2435 If you wish, while reading your mail, to send a message to some‐
2437 one, but not as a reply to one of your messages, you can send
2438 the message directly with the mail command, which takes as argu‐
2439 ments the names of the recipients you wish to send to. For
2440 example, to send a message to <frank@machine.example>, you would
2441 do:
2442 mail frank@machine.example
2444 To delete a message from the mail folder, you can use the delete
2446 command. In addition to not saving deleted messages, nail will
2447 not let you type them, either. The effect is to make the mes‐
2448 sage disappear altogether, along with its number.
2449 Many features of nail can be tailored to your liking with the
2451 set command. The set command has two forms, depending on
2452 whether you are setting a binary option or a valued option.
2453 Binary options are either on or off. For example, the askcc
2454 option informs nail that each time you send a message, you want
2455 it to prompt you for a `Cc:' header, to be included in the mes‐
2456 sage. To set the askcc option, you would type
2457 set askcc
2459 Valued options are values which nail uses to adapt to your
2461 tastes. For example, the record option tells nail where to save
2462 messages sent by you, and is specified by
2463 set record=Sent
2465 for example. Note that no spaces are allowed in set record=Sent
2467 .
2468 Nail includes a simple facility for maintaining groups of mes‐
2470 sages together in folders. To use the folder facility, you must
2471 tell nail where you wish to keep your folders. Each folder of
2472 messages will be a single file. For convenience, all of your
2473 folders are kept in a single directory of your choosing. To
2474 tell nail where your folder directory is, put a line of the form
2475 set folder=letters
2477 in your .mailrc file. If, as in the example above, your folder
2479 directory does not begin with a `/', nail will assume that your
2480 folder directory is to be found starting from your home direc‐
2481 tory.
2482 Anywhere a file name is expected, you can use a folder name,
2484 preceded with `+'. For example, to put a message into a folder
2485 with the save command, you can use:
2486 save +classwork
2488 to save the current message in the classwork folder. If the
2490 classwork folder does not yet exist, it will be created. Note
2491 that messages which are saved with the save command are automat‐
2492 ically removed from your system mailbox.
2493 In order to make a copy of a message in a folder without causing
2495 that message to be removed from your system mailbox, use the
2496 copy command, which is identical in all other respects to the
2497 save command.
2498 The folder command can be used to direct nail to the contents of
2500 a different folder. For example,
2501 folder +classwork
2503 directs nail to read the contents of the classwork folder. All
2505 of the commands that you can use on your system mailbox are also
2506 applicable to folders, including type, delete, and reply. To
2507 inquire which folder you are currently editing, use simply:
2508 folder
2510 To list your current set of folders, use the folders command.
2512 Finally, the help command is available to print out a brief sum‐
2514 mary of the most important nail commands.
2515 While typing in a message to be sent to others, it is often use‐
2517 ful to be able to invoke the text editor on the partial message,
2518 print the message, execute a shell command, or do some other
2519 auxiliary function. Nail provides these capabilities through
2520 tilde escapes , which consist of a tilde (~) at the beginning of
2521 a line, followed by a single character which indicates the func‐
2522 tion to be performed. For example, to print the text of the
2523 message so far, use:
2524 ~p
2526 which will print a line of dashes, the recipients of your mes‐
2528 sage, and the text of the message so far. A list of the most
2529 important tilde escapes is available with `~?'.
2530 IMAP or POP3 client setup
2532 First you need the following data from your ISP: the host name
2533 of the IMAP or POP3 server, user name and password for this
2534 server, and a notice whether the server uses SSL/TLS encryption.
2535 Assuming the host name is `server.myisp.example' and your user
2536 name for that server is `mylogin', you can refer to this account
2537 using the folder command or -f command line option with
2538 imaps://mylogin@server.myisp.example
2540 (This string is not necessarily the same as your Internet mail
2542 address.) You can replace `imaps://' with `imap://' if the
2543 server does not support SSL/TLS. (If SSL/TLS support is built
2544 using NSS, the nss-config-dir variable must be set before a con‐
2545 nection can be initiated, see above). Use `pop3s://' or
2546 `pop3://' if the server does not offer IMAP. You should use
2547 IMAP if you can, though; first because it requires fewer network
2548 operations than POP3 to get the contents of the mailbox and is
2549 thus faster; and second because message attributes are main‐
2550 tained by the IMAP server, so you can easily distinguish new and
2551 old messages each time you connect. Even if the server does not
2552 accept IMAPS or POP3S connections, it is possible that it sup‐
2553 ports the STARTTLS method to make a session SSL/TLS encrypted
2554 after the initial connection has been performed, but before
2555 authentication begins. The only reliable method to see if this
2556 works is to try it; enter one of
2557 set imap-use-starttls
2559 set pop3-use-starttls
2560 before you initiate the connection.
2562 As you probably want messages to be deleted from this account
2564 after saving them, prefix it with `%:'. The shortcut command
2565 can be used to avoid typing that many characters every time you
2566 want to connect:
2567 shortcut myisp %:imaps://mylogin@server.myisp.example
2569 You might want to put this string into a startup file. As the
2571 shortcut command is specific to this implementation of nail and
2572 will confuse other implementations, it should not be used in
2573 ~/.mailrc, instead, put
2574 set NAIL_EXTRA_RC=~/.nailrc
2576 in ~/.mailrc and create a file ~/.nailrc containing the shortcut
2578 command above. You can then access your remote mailbox by
2579 invoking `nail -f myisp' on the command line, or by executing
2580 `fi myisp' within nail.
2581 If you want to use more than one IMAP mailbox on a server, or if
2583 you want to use the IMAP server for mail storage too, the
2584 account command (which is also nail-specific) is more appropri‐
2585 ate than the shortcut command. You can put the following in
2586 ~/.nailrc:
2587 account myisp {
2589 set folder=imaps://mylogin@server.myisp.example
2590 set record=+Sent MBOX=+mbox outfolder
2591 }
2592 and can then access incoming mail for this account by invoking
2594 `nail -A myisp' on the command line, or by executing `ac myisp'
2595 within nail. After that, a command like `copy 1 +otherfolder'
2596 will refer to otherfolder on the IMAP server. In particular,
2597 `fi &' will change to the mbox folder, and `fi +Sent' will show
2598 your recorded sent mail, with both folders located on the IMAP
2599 server.
2600 Nail will ask you for a password string each time you connect to
2602 a remote account. If you can reasonably trust the security of
2603 your workstation, you can give this password in the startup file
2604 as
2605 set password-mylogin@server.myisp.example="SECRET"
2607 You should change the permissions of this file to 0600, see
2609 chmod(1).
2610 Nail supports different authentication methods for both IMAP and
2612 POP3. If Kerberos is used at your location, you can try to
2613 activate GSSAPI-based authentication by
2614 set imap-auth=gssapi
2616 The advantage of this method is that nail does not need to know
2618 your password at all, nor needs to send sensitive data over the
2619 network. Otherwise, the options
2620 set imap-auth=cram-md5
2622 set pop3-use-apop
2623 for IMAP and POP3, respectively, offer authentication methods
2625 that avoid to send the password in clear text over the network,
2626 which is especially important if SSL/TLS cannot be used. If the
2627 server does not offer any of these authentication methods, con‐
2628 ventional user/password based authentication must be used. It
2629 is sometimes helpful to set the verbose option when authentica‐
2630 tion problems occur. Nail will display all data sent to the
2631 server in clear text on the screen with this option, including
2632 passwords. You should thus take care that no unauthorized per‐
2633 son can look at your terminal when this option is set.
2634 If you regularly use the same workstation to access IMAP
2636 accounts, you can greatly enhance performance by enabling local
2637 caching of IMAP messages. For any message that has been fully
2638 or partially fetched from the server, a local copy is made and
2639 is used when the message is accessed again, so most data is
2640 transferred over the network once only. To enable the IMAP
2641 cache, select a local directory name and put
2642 set imap-cache=~/localdirectory
2644 in the startup file. All files within that directory can be
2646 overwritten or deleted by nail at any time, so you should not
2647 use the directory to store other information.
2648 Once the cache contains some messages, it is not strictly neces‐
2650 sary anymore to open a connection to the IMAP server to access
2651 them. When nail is invoked with the -D option, or when the dis‐
2652 connected variable is set, only cached data is used for any
2653 folder you open. Messages that have not yet been completely
2654 cached are not available then, but all other messages can be
2655 handled as usual. Changes made to IMAP mailboxes in discon‐
2656 nected mode are committed to the IMAP server next time it is
2657 used in online mode. Synchronizing the local status with the
2658 status on the server is thus partially within your responsibil‐
2659 ity; if you forget to initiate a connection to the server again
2660 before you leave your location, changes made on one workstation
2661 are not available on others. Also if you alter IMAP mailboxes
2662 from a workstation while uncommitted changes are still pending
2663 on another, the latter data may become invalid. The same might
2664 also happen because of internal server status changes. You
2665 should thus carefully evaluate this feature in your environment
2666 before you rely on it.
2667 Many servers will close the connection after a short period of
2669 inactivity. Use one of
2670 set pop3-keepalive=30
2672 set imap-keepalive=240
2673 to send a keepalive message each 30 seconds for POP3, or each 4
2675 minutes for IMAP.
2676 If you encounter problems connecting to a SSL/TLS server, try
2678 the ssl-rand-egd and ssl-rand-file variables (see the OpenSSL
2679 FAQ for more information) or specify the protocol version with
2680 ssl-method. Contact your ISP if you need a client certificate
2681 or if verification of the server certificate fails. If the
2682 failed certificate is indeed valid, fetch its CA certificate by
2683 executing the shell command
2684 $ openssl s_client </dev/null -showcerts -connect \
2686 server.myisp.example:imaps 2>&1 | tee log
2687 (see s_client(1)) and put it into the file specified with ssl-
2689 ca-file. The data you need is located at the end of the cer‐
2690 tificate chain within (and including) the `BEGIN CERTIFICATE'
2691 and `END CERTIFICATE' lines. (Note that it is possible to fetch
2692 a forged certificate by this method. You can only completely
2693 rely on the authenticity of the CA certificate if you fetch it
2694 in a way that is trusted by other means, such as by personally
2695 receiving the certificate on storage media.)
2696 Creating a score file or message filter
2698 The scoring commands are best separated from other configuration
2699 for clarity, and are mostly nail specific. It is thus recom‐
2700 mended to put them in a separate file that is sourced from your
2701 NAIL_EXTRA_RC as follows:
2702 source ~/.scores
2704 The .scores file could then look as follows:
2706 define list {
2708 score (subject "important discussion") +10
2709 score (subject "annoying discussion") -10
2710 score (from "nicefellow@goodnet") +15
2711 score (from "badguy@poornet") -5
2712 move (header x-spam-flag "+++++") +junk
2713 }
2714 set folder-hook-imap://user@host/public.list=list
2715 In this scheme, you would see any mail from `nicefellow@good‐
2717 net', even if the surrounding discussion is annoying; but you
2718 normally would not see mail from `badguy@poornet', unless he
2719 participates in the important discussion. Messages that are
2720 marked with five or more plus characters in their `X-Spam-Flag'
2721 field (inserted by some server-side filtering software) are
2722 moved to the folder `junk' in the folder directory.
2723 Be aware that all criteria in () lead to substring matches, so
2725 you would also score messages from e.g. `notsobadguy@poornetmak‐
2726 ers' negative here. It is possible to select addresses exactly
2727 using "address" message specifications, but these cannot be exe‐
2728 cuted remotely and will thus cause all headers to be downloaded
2729 from IMAP servers while looking for matches.
2730 When searching messages on an IMAP server, best performance is
2732 usually achieved by sending as many criteria as possible in one
2733 large () specification, because each single such specification
2734 will result in a separate network operation.
2735 Activating the Bayesian filter
2737 The Bayesian junk mail filter works by examining the words con‐
2738 tained in messages. You decide yourself what a good and what a
2739 bad message is. Thus the resulting filter is your very personal
2740 one; once it is correctly set up, it will filter only messages
2741 similar to those previously specified by you.
2742 To use the Bayesian filter, a location for the junk mail data‐
2744 base must be defined first:
2745 set junkdb=~/.junkdb
2747 The junk mail database does not contain actual words extracted
2749 from messages, but hashed representations of them. A foreign
2750 person who can read the database could only examine the fre‐
2751 quency of previously known words in your mail.
2752 If you have sufficient disk space (several 10 MB) available, it
2754 is recommended that you set the chained-junk-tokens option. The
2755 filter will then also consider two-word tokens, improving its
2756 accuracy.
2757 A set of good messages and junk messages must now be available;
2759 it is also possible to use the incoming new messages for this
2760 purpose, although it will of course take some time until the
2761 filter becomes useful then. Do not underestimate the amount of
2762 statistical data needed; some hundred messages are typically
2763 necessary to get satisfactory results, and many thousand mes‐
2764 sages for best operation. You have to pass the good messages to
2765 the good command, and the junk messages to the junk command. If
2766 you ever accidentally mark a good message as junk or vice-versa,
2767 call the ungood or unjunk command to correct this.
2768 Once a reasonable amount of statistics has been collected, new
2770 messages can be classified automatically. The classify command
2771 marks all messages that the filter considers to be junk, but it
2772 does not perform any action on them by default. It is recom‐
2773 mended that you move these messages into a separate folder just
2774 for the case that false positives occur, or to pass them to the
2775 junk command later again to further improve the junk mail data‐
2776 base. To automatically move incoming junk messages every time
2777 the inbox is opened, put lines like the following into your
2778 .scores file (or whatever name you gave to the file in the last
2779 example):
2780 define junkfilter {
2782 classify (smaller 20000) :n
2783 move :j +junk
2784 }
2785 set folder-hook-imap://user@host/INBOX=junkfilter
2786 If you set the verbose option before running the classify com‐
2788 mand, nail prints the words it uses for calculating the junk
2789 status along with their statistical probabilities. This can
2790 help you to find out why some messages are not classified as you
2791 would like them to be. To see the statistical probability of a
2792 given word, use the probability command.
2793 If a junk message was not recognized as such, use the junk com‐
2795 mand to correct this. Also if you encounter a false positive (a
2796 good message that was wrongly classified as junk), pass it to
2797 the good command.
2798 Since the classify command must examine the entire text of all
2800 new messages in the respective folder, this will also cause all
2801 of them to be downloaded from the IMAP server. You should thus
2802 restrict the size of messages for automatic filtering. If
2803 server-based filtering is also available, you might try if that
2804 works for you first.
2805 Reading HTML mail
2807 You need either the w3m or lynx utility or another command-line
2808 web browser that can write plain text to standard output.
2809 set pipe-text/html="w3m -dump -T text/html"
2811 or
2813 set pipe-text/html="lynx -dump -force_html /dev/stdin"
2815 will then cause HTML message parts to be converted into a more
2817 friendly form.
2818 Viewing PDF attachments
2820 Most PDF viewers do not accept input directly from a pipe. It
2821 is thus necessary to store the attachment in a temporary file,
2822 as with
2823 set pipe-application/pdf="cat >/tmp/nail$$.pdf; \
2825 acroread /tmp/nail$$.pdf; rm /tmp/nail$$.pdf"
2826 Note that security defects are discovered in PDF viewers from
2828 time to time. Automatical command execution like this can com‐
2829 promise your system security, in particular if you stay not
2830 always informed about such issues.
2831 Signed and encrypted messages with S/MIME
2833 S/MIME provides two central mechanisms: message signing and mes‐
2834 sage encryption. A signed message contains some data in addi‐
2835 tion to the regular text. The data can be used to verify that
2836 the message was sent using a valid certificate, that the
2837 sender's address in the message header matches that in the cer‐
2838 tificate, and that the message text has not been altered. Sign‐
2839 ing a message does not change its regular text; it can be read
2840 regardless of whether the recipient's software is able to handle
2841 S/MIME. It is thus usually possible to sign all outgoing mes‐
2842 sages if so desired.—Encryption, in contrast, makes the message
2843 text invisible for all people except those who have access to
2844 the secret decryption key. To encrypt a message, the specific
2845 recipient's public encryption key must be known. It is thus not
2846 possible to send encrypted mail to people unless their key has
2847 been retrieved from either previous communication or public key
2848 directories. A message should always be signed before it is
2849 encrypted. Otherwise, it is still possible that the encrypted
2850 message text is altered.
2851 A central concept to S/MIME is that of the certification author‐
2853 ity (CA). A CA is a trusted institution that issues certifi‐
2854 cates. For each of these certificates, it can be verified that
2855 it really originates from the CA, provided that the CA's own
2856 certificate is previously known. A set of CA certificates is
2857 usually delivered with OpenSSL and installed on your system. If
2858 you trust the source of your OpenSSL software installation, this
2859 offers reasonable security for S/MIME on the Internet. In gen‐
2860 eral, a certificate cannot be more secure than the method its CA
2861 certificate has been retrieved with, though. Thus if you down‐
2862 load a CA certificate from the Internet, you can only trust the
2863 messages you verify using that certificate as much as you trust
2864 the download process.
2865 The first thing you need for participating in S/MIME message
2867 exchange is your personal certificate, including a private key.
2868 The certificate contains public information, in particular your
2869 name and your email address, and the public key that is used by
2870 others to encrypt messages for you, and to verify signed mes‐
2871 sages they supposedly received from you. The certificate is
2872 included in each signed message you send. The private key must
2873 be kept secret. It is used to decrypt messages that were previ‐
2874 ously encrypted with your public key, and to sign messages.
2875 For personal use, it is recommended that you get a S/MIME cer‐
2877 tificate from one of the major CAs on the Internet using your
2878 WWW browser. (Many CAs offer such certificates for free.) You
2879 will usually receive a combined certificate and private key in
2880 PKCS#12 format which nail does not directly accept if S/MIME
2881 support is built using OpenSSL. To convert it to PEM format,
2882 use the following shell command:
2883 $ openssl pkcs12 -in cert.p12 -out cert.pem -clcerts \
2885 -nodes
2886 If you omit the -nodes parameter, you can specifiy an additional
2888 PEM pass phrase for protecting the private key. Nail will then
2889 ask you for that pass phrase each time it signs or decrypts a
2890 message. You can then use
2891 set smime-sign-cert-myname@myisp.example=cert.pem
2893 to make this private key and certificate known to nail.
2895 If S/MIME support is built using NSS, the PKCS#12 file must be
2897 installed using Mozilla (provided that nss-config-dir is set
2898 appropriately, see above), and no further action is necessary
2899 unless multiple user certificates for the same email address are
2900 installed. In this case, the smime-sign-nickname variable has
2901 to be set appropriately.
2902 You can now sign outgoing messages. Just use
2904 set smime-sign
2906 to do so.
2908 From each signed message you send, the recipient can fetch your
2910 certificate and use it to send encrypted mail back to you.
2911 Accordingly if somebody sends you a signed message, you can do
2912 the same. First use the verify command to check the validity of
2913 the certificate. After that, retrieve the certificate and tell
2914 nail that it should use it for encryption:
2915 certsave filename
2917 set smime-encrypt-user@host=filename
2918 If S/MIME support is built using NSS, the saved certificate must
2920 be installed using Mozilla. The value of the smime-encrypt-
2921 user@host is ignored then, but if multiple certificates for the
2922 recipient are available, the smime-nickname-user@host variable
2923 must be set.
2924 You should carefully consider if you prefer to store encrypted
2926 messages in decrypted form. If you do, anybody who has access
2927 to your mail folders can read them, but if you do not, you might
2928 be unable to read them yourself later if you happen to lose your
2929 private key. The decrypt command saves messages in decrypted
2930 form, while the save, copy, and move commands leave them
2931 encrypted.
2932 Note that neither S/MIME signing nor encryption applies to mes‐
2934 sage subjects or other header fields. Thus they may not contain
2935 sensitive information for encrypted messages, and cannot be
2936 trusted even if the message content has been verified. When
2937 sending signed messages, it is recommended to repeat any impor‐
2938 tant header information in the message text.
2939 Using CRLs with S/MIME or SSL/TLS
2941 Certification authorities (CAs) issue certificate revocation
2942 lists (CRLs) on a regular basis. These lists contain the serial
2943 numbers of certificates that have been declared invalid after
2944 they have been issued. Such usually happens because the private
2945 key for the certificate has been compromised, because the owner
2946 of the certificate has left the organization that is mentioned
2947 in the certificate, etc. To seriously use S/MIME or SSL/TLS
2948 verification, an up-to-date CRL is required for each trusted CA.
2949 There is otherwise no method to distinguish between valid and
2950 invalidated certificates. Nail currently offers no mechanism to
2951 fetch CRLs, or to access them on the Internet, so you have to
2952 retrieve them by some external mechanism.
2953 If S/MIME and SSL/TLS support are built using OpenSSL, nail
2955 accepts CRLs in PEM format only; CRLs in DER format must be con‐
2956 verted, e.g. with the shell command
2957 $ openssl crl -inform DER -in crl.der -out crl.pem
2959 To tell nail about the CRLs, a directory that contains all CRL
2961 files (and no other files) must be created. The smime-crl-dir
2962 or ssl-crl-dir variables, respectively, must then be set to
2963 point to that directory. After that, nail requires a CRL to be
2964 present for each CA that is used to verify a certificate.
2965 If S/MIME and SSL/TLS support are built using NSS, CRLs can be
2967 imported in Mozilla applications (provided that nss-config-dir
2968 is set appropriately).
2969 Sending mail from scripts
2971 If you want to send mail from scripts, you must be aware that
2972 nail reads the user's configuration files by default. So unless
2973 your script is only intended for your own personal use (as e.g.
2974 a cron job), you need to circumvent this by invoking nail like
2975 MAILRC=/dev/null nail -n
2977 You then need to create a configuration for nail for your
2979 script. This can be done by either pointing the MAILRC variable
2980 to a custom configuration file, or by passing the configuration
2981 in environment variables. Since many of the configuration
2982 options are not valid shell variables, the env command is useful
2983 in this situation. An invocation could thus look like
2984 env MAILRC=/dev/null from=scriptreply@domain smtp=host \
2986 smtp-auth-user=login smtp-auth-password=secret \
2987 smtp-auth=login nail -n -s "subject" \
2988 -a attachment_file recipient@domain <content_file
2989
2991 fmt(1), newaliases(1), openssl(1), pg(1), more(1), vacation(1),
2992 ssl(3), aliases(5), locale(7), mailaddr(7), sendmail(8)
2993
2995 Variables in the environment passed to nail cannot be unset.
2996 The character set conversion relies on the iconv(3) function.
2998 Its functionality differs widely between the various system
2999 environments nail runs on. If the message `Cannot convert from
3000 a to b' appears, either some characters within the message
3001 header or text are not appropriate for the currently selected
3002 terminal character set, or the needed conversion is not sup‐
3003 ported by the system. In the first case, it is necessary to set
3004 an appropriate LC_CTYPE locale (e.g. en_US) or the ttycharset
3005 variable. In the second case, the sendcharsets and ttycharset
3006 variables must be set to the same value to inhibit character set
3007 conversion. If iconv() is not available at all, the value
3008 assigned to sendcharsets must match the character set that is
3009 used on the terminal.
3010 Nail expects input text to be in Unix format, with lines sepa‐
3012 rated by newline (^J, \n) characters only. Non-Unix text files
3013 that use carriage return (^M, \r) characters in addition will be
3014 treated as binary data; to send such files as text, strip these
3015 characters e. g. by
3016 tr -d '\015' <input | nail . . .
3018 or fix the tools that generate them.
3020 Limitations with IMAP mailboxes are: It is not possible to edit
3022 messages, but it is possible to append them. Thus to edit a
3023 message, create a local copy of it, edit it, append it, and
3024 delete the original. The line count for the header display is
3025 only appropriate if the entire message has been downloaded from
3026 the server. The marking of messages as `new' is performed by
3027 the IMAP server; use of the exit command instead of quit will
3028 not cause it to be reset, and if the autoinc/newmail variables
3029 are unset, messages that arrived during a session will not be in
3030 state `new' anymore when the folder is opened again. Also if
3031 commands queued in disconnected mode are committed, the IMAP
3032 server will delete the `new' flag for all messages in the
3033 changed folder, and new messages will appear as unread when it
3034 is selected for viewing later. The `flagged', `answered', and
3035 `draft' attributes are usually permanent, but some IMAP servers
3036 are known to drop them without notification. Message numbers
3037 may change with IMAP every time before the prompt is printed if
3038 nail is notified by the server that messages have been deleted
3039 by some other client or process. In this case, `Expunged n mes‐
3040 sages' is printed, and message numbers may have changed.
3041 Limitations with POP3 mailboxes are: It is not possible to edit
3043 messages, they can only be copied and deleted. The line count
3044 for the header display is only appropriate if the entire message
3045 has been downloaded from the server. The status field of a mes‐
3046 sage is maintained by the server between connections; some
3047 servers do not update it at all, and with a server that does,
3048 the `exit' command will not cause the message status to be
3049 reset. The `newmail' command and the `newmail' variable have no
3050 effect. It is not possible to rename or to remove POP3 mail‐
3051 boxes.
3052 If a RUBOUT (interrupt) is typed while an IMAP or POP3 operation
3054 is in progress, nail will wait until the operation can be safely
3055 aborted, and will then return to the command loop and print the
3056 prompt again. When a second RUBOUT is typed while nail is wait‐
3057 ing for the operation to complete, the operation itself will be
3058 canceled. In this case, data that has not been fetched yet will
3059 have to be fetched before the next command can be performed. If
3060 the canceled operation was using an SSL/TLS encrypted channel,
3061 an error in the SSL transport will very likely result, and the
3062 connection is no longer usable.
3063 As nail is a mail user agent, it provides only basic SMTP ser‐
3065 vices. If it fails to contact its upstream SMTP server, it will
3066 not make further attempts to transfer the message at a later
3067 time, and it does not leave other information about this condi‐
3068 tion than an error message on the terminal and a `dead.letter'
3069 file. This is usually not a problem if the SMTP server is
3070 located in the same local network as the computer on which nail
3071 is run. However, care should be taken when using a remote
3072 server of an ISP; it might be better to set up a local SMTP
3073 server then which just acts as a proxy.
3074 Nail immediately contacts the SMTP server (or /usr/lib/sendmail)
3076 even when operating in disconnected mode. It would not make
3077 much sense for nail to defer outgoing mail since SMTP servers
3078 usually provide much more elaborated delay handling than nail
3079 could perform as a client. Thus the recommended setup for send‐
3080 ing mail in disconnected mode is to configure a local SMTP
3081 server such that it sends outgoing mail as soon as an external
3082 network connection is available again, i.e. to advise it to do
3083 that from a network startup script.
3084 The junk mail filter follows the concepts developed by Paul Gra‐
3086 ham in his articles, ``A Plan for Spam'', August 2002,
3087 <http://www.paulgraham.com/spam.html>, and ``Better Bayesian
3088 Filtering'', January 2003,
3089 <http://www.paulgraham.com/better.html>. Chained tokens are due
3090 to a paper by Jonathan A. Zdziarski, ``Advanced Language Classi‐
3091 fication using Chained Tokens'', February 2004,
3092 <http://www.nuclearelephant.com/papers/chained.html>.
3093 A mail command appeared in Version 1 AT&T Unix. Berkeley Mail
3095 was written in 1978 by Kurt Shoens. This man page is derived
3096 from from The Mail Reference Manual originally written by Kurt
3097 Shoens. Heirloom Mailx enhancements are maintained and docu‐
3098 mented by Gunnar Ritter.
3099 Portions of this text are reprinted and reproduced in electronic
3101 form from IEEE Std 1003.1, 2003 Edition, Standard for Informa‐
3102 tion Technology — Operating System Interface (POSIX), The Open
3103 Group Base Specifications Issue 6, Copyright © 2001-2003 by the
3104 Institute of Electrical and Electronics Engineers, Inc and The
3105 Open Group. In the event of any discrepancy between this version
3106 and the original IEEE and The Open Group Standard, the original
3107 IEEE and The Open Group Standard is the referee document. The
3108 original Standard can be obtained online at
3109 http://www.opengroup.org/unix/online.html . Redistribution of
3110 this material is permitted so long as this notice remains
3111 intact.
3112Heirloom mailx 12.3 2/16/07 MAILX(1)