[gnus] / lisp / nnmail.el

;;; nnmail.el --- mail support functions for the Gnus mail backends
;; Copyright (C) 1995,96 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
;; Keywords: news, mail

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(require 'nnheader)
(require 'rmail)
(require 'timezone)
(require 'sendmail)
(eval-when-compile (require 'cl))

(defvar nnmail-split-methods
  '(("mail.misc" ""))
  "*Incoming mail will be split according to this variable.

If you'd like, for instance, one mail group for mail from the
\"4ad-l\" mailing list, one group for junk mail and one for everything
else, you could do something like this:

 (setq nnmail-split-methods
       '((\"mail.4ad\" \"From:.*4ad\")
         (\"mail.junk\" \"From:.*Lars\\\\|Subject:.*buy\")
         (\"mail.misc\" \"\")))

As you can see, this variable is a list of lists, where the first
element in each \"rule\" is the name of the group (which, by the way,
does not have to be called anything beginning with \"mail\",
\"yonka.zow\" is a fine, fine name), and the second is a regexp that
nnmail will try to match on the header to find a fit.

The second element can also be a function.  In that case, it will be
called narrowed to the headers with the first element of the rule as
the argument.  It should return a non-nil value if it thinks that the
mail belongs in that group.

The last element should always have \"\" as the regexp.

This variable can also have a function as its value.")

;; Suggested by Erik Selberg <speed@cs.washington.edu>.
(defvar nnmail-crosspost t
  "*If non-nil, do crossposting if several split methods match the mail.
If nil, the first match found will be used.")

;; Added by gord@enci.ucalgary.ca (Gordon Matzigkeit).
(defvar nnmail-keep-last-article nil
  "*If non-nil, nnmail will never delete the last expired article in a directory.  
You may need to set this variable if other programs are putting
new mail into folder numbers that Gnus has marked as expired.")

(defvar nnmail-use-long-file-names nil
  "*If non-nil the mail backends will use long file and directory names.
If nil, groups like \"mail.misc\" will end up in directories like
\"mail/misc/\".")

(defvar nnmail-expiry-wait 7
  "*Expirable articles that are older than this will be expired.
This variable can either be a number (which will be interpreted as a
number of days) -- this doesn't have to be an integer.  This variable
can also be `immediate' and `never'.")

(defvar nnmail-expiry-wait-function nil
  "*Variable that holds function to specify how old articles should be before they are expired.
  The function will be called with the name of the group that the
expiry is to be performed in, and it should return an integer that
says how many days an article can be stored before it is considered
\"old\".  It can also return the values `never' and `immediate'.

Eg.:

(setq nnmail-expiry-wait-function
      (lambda (newsgroup)
        (cond ((string-match \"private\" newsgroup) 31)
              ((string-match \"junk\" newsgroup) 1)
              ((string-match \"important\" 'never))
              (t 7))))")

(defvar nnmail-spool-file 
  (or (getenv "MAIL")
      (concat "/usr/spool/mail/" (user-login-name)))
  "Where the mail backends will look for incoming mail.
This variable is \"/usr/spool/mail/$user\" by default.
If this variable is nil, no mail backends will read incoming mail.
If this variable is a list, all files mentioned in this list will be
used as incoming mailboxes.")

(defvar nnmail-crash-box "~/.gnus-crash-box"
  "*File where Gnus will store mail while processing it.")

(defvar nnmail-use-procmail nil
  "*If non-nil, the mail backends will look in `nnmail-procmail-directory' for spool files.
The file(s) in `nnmail-spool-file' will also be read.")

(defvar nnmail-procmail-directory "~/incoming/"
  "*When using procmail (and the like), incoming mail is put in this directory.
The Gnus mail backends will read the mail from this directory.")

(defvar nnmail-procmail-suffix "\\.spool"
  "*Suffix of files created by procmail (and the like).
This variable might be a suffix-regexp to match the suffixes of
several files - eg. \".spool[0-9]*\".")

(defvar nnmail-resplit-incoming nil
  "*If non-nil, re-split incoming procmail sorted mail.")

(defvar nnmail-delete-file-function 'delete-file
  "Function called to delete files in some mail backends.")

(defvar nnmail-crosspost-link-function 'add-name-to-file
  "Function called to create a copy of a file.
This is `add-name-to-file' by default, which means that crossposts
will use hard links.  If your file system doesn't allow hard
links, you could set this variable to `copy-file' instead.")

(defvar nnmail-movemail-program "movemail"
  "*A command to be executed to move mail from the inbox.
The default is \"movemail\".")

(defvar nnmail-read-incoming-hook nil
  "*Hook that will be run after the incoming mail has been transferred.
The incoming mail is moved from `nnmail-spool-file' (which normally is
something like \"/usr/spool/mail/$user\") to the user's home
directory. This hook is called after the incoming mail box has been
emptied, and can be used to call any mail box programs you have
running (\"xwatch\", etc.)

Eg.

\(add-hook 'nnmail-read-incoming-hook 
           (lambda () 
             (start-process \"mailsend\" nil 
                            \"/local/bin/mailsend\" \"read\" \"mbox\")))

If you have xwatch running, this will alert it that mail has been
read.  

If you use `display-time', you could use something like this:

\(add-hook 'nnmail-read-incoming-hook
          (lambda ()
            ;; Update the displayed time, since that will clear out
            ;; the flag that says you have mail.
            (if (eq (process-status \"display-time\") 'run)
                (display-time-filter display-time-process \"\"))))") 

;; Suggested by Erik Selberg <speed@cs.washington.edu>.
(defvar nnmail-prepare-incoming-hook nil
  "*Hook called before treating incoming mail.
The hook is run in a buffer with all the new, incoming mail.")

(defvar nnmail-pre-get-new-mail-hook nil
  "Hook called just before starting to handle new incoming mail.")

(defvar nnmail-post-get-new-mail-hook nil
  "Hook called just after finishing handling new incoming mail.")

;; Suggested by Mejia Pablo J <pjm9806@usl.edu>.
(defvar nnmail-tmp-directory nil
  "*If non-nil, use this directory for temporary storage when reading incoming mail.")

(defvar nnmail-large-newsgroup 50
  "*The number of the articles which indicates a large newsgroup.
If the number of the articles is greater than the value, verbose
messages will be shown to indicate the current status.")

(defvar nnmail-split-fancy "mail.misc"
  "*Incoming mail can be split according to this fancy variable.
To enable this, set `nnmail-split-methods' to `nnmail-split-fancy'.

The format is this variable is SPLIT, where SPLIT can be one of
the following:

GROUP: Mail will be stored in GROUP (a string).

\(FIELD VALUE SPLIT): If the message field FIELD (a regexp) contains
  VALUE (a regexp), store the messages as specified by SPLIT.

\(| SPLIT...): Process each SPLIT expression until one of them matches.
  A SPLIT expression is said to match if it will cause the mail
  message to be stored in one or more groups.  

\(& SPLIT...): Process each SPLIT expression.

FIELD must match a complete field name.  VALUE must match a complete
word according to the `nnmail-split-fancy-syntax-table' syntax table.
You can use .* in the regexps to match partial field names or words.

FIELD and VALUE can also be lisp symbols, in that case they are expanded
as specified in `nnmail-split-abbrev-alist'.

Example:

\(setq nnmail-split-methods 'nnmail-split-fancy
      nnmail-split-fancy
      ;; Messages from the mailer deamon are not crossposted to any of
      ;; the ordinary groups.  Warnings are put in a separate group
      ;; from real errors.
      '(| (\"from\" mail (| (\"subject\" \"warn.*\" \"mail.warning\")
                          \"mail.misc\"))
          ;; Non-error messages are crossposted to all relevant
          ;; groups, but we don't crosspost between the group for the
          ;; (ding) list and the group for other (ding) related mail.
          (& (| (any \"ding@ifi\\\\.uio\\\\.no\" \"ding.list\")
                (\"subject\" \"ding\" \"ding.misc\"))
             ;; Other mailing lists...
             (any \"procmail@informatik\\\\.rwth-aachen\\\\.de\" \"procmail.list\")
             (any \"SmartList@informatik\\\\.rwth-aachen\\\\.de\" \"SmartList.list\")
             ;; People...
             (any \"larsi@ifi\\\\.uio\\\\.no\" \"people.Lars Magne Ingebrigtsen\"))
          ;; Unmatched mail goes to the catch all group.
          \"misc.misc\"))")

(defvar nnmail-split-abbrev-alist
  '((any . "from\\|to\\|cc\\|sender\\|apparently-to")
    (mail . "mailer-daemon\\|postmaster"))
  "*Alist of abbreviations allowed in `nnmail-split-fancy'.")

(defvar nnmail-delete-incoming nil
  "*If non-nil, the mail backends will delete incoming files after splitting.")

(defvar nnmail-message-id-cache-length 1000
  "*The approximate number of Message-IDs nnmail will keep in its cache.
If this variable is nil, no checking on duplicate messages will be
performed.")

(defvar nnmail-message-id-cache-file "~/.nnmail-cache"
  "*The file name of the nnmail Message-ID cache.")

(defvar nnmail-treat-duplicates 'warn
  "*If non-nil, nnmail keep a cache of Message-IDs to discover mail duplicates.
Three values are legal: nil, which means that nnmail is not to keep a
Message-ID cache; `warn', which means that nnmail should insert extra
headers to warn the user about the duplication (this is the default);
and `delete', which means that nnmail will delete duplicated mails.

This variable can also be a function.  It will be called from a buffer
narrowed to the article in question with the Message-ID as a
parameter.  It should return nil, `warn' or `delete'.")

;;; Internal variables.

(defvar nnmail-split-fancy-syntax-table
  (copy-syntax-table (standard-syntax-table))
  "Syntax table used by `nnmail-split-fancy'.")

\f

(defconst nnmail-version "nnmail 1.0"
  "nnmail version.")

\f