Update copyright year to 2015

[gnus] / lisp / nnmail.el

;;; nnmail.el --- mail support functions for the Gnus mail backends

;; Copyright (C) 1995-2015 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))

(require 'gnus)                         ; for macro gnus-kill-buffer, at least
(require 'nnheader)
(require 'message)
(require 'gnus-util)
(require 'mail-source)
(require 'mm-util)
(require 'gnus-int)

(autoload 'gnus-add-buffer "gnus")
(autoload 'gnus-kill-buffer "gnus")
(eval-when-compile
  (autoload 'mail-send-and-exit "sendmail" nil t))

(defgroup nnmail nil
  "Reading mail with Gnus."
  :group 'gnus)

(defgroup nnmail-retrieve nil
  "Retrieving new mail."
  :group 'nnmail)

(defgroup nnmail-prepare nil
  "Preparing (or mangling) new mail after retrieval."
  :group 'nnmail)

(defgroup nnmail-duplicate nil
  "Handling of duplicate mail messages."
  :group 'nnmail)

(defgroup nnmail-split nil
  "Organizing the incoming mail in folders."
  :group 'nnmail)

(defgroup nnmail-files nil
  "Mail files."
  :group 'gnus-files
  :group 'nnmail)

(defgroup nnmail-expire nil
  "Expiring old mail."
  :group 'nnmail)

(defgroup nnmail-procmail nil
  "Interfacing with procmail and other mail agents."
  :group 'nnmail)

(defgroup nnmail-various nil
  "Various mail options."
  :group 'nnmail)

(defcustom 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, and it can
also have a fancy split method as its value.  See
`nnmail-split-fancy' for an explanation of that syntax."
  :group 'nnmail-split
  :type '(choice (repeat :tag "Alist" (group (string :tag "Name")
                                             (choice regexp function)))
                 (function-item nnmail-split-fancy)
                 (function :tag "Other")))

;; Suggested by Erik Selberg <speed@cs.washington.edu>.
(defcustom nnmail-crosspost t
  "If non-nil, do crossposting if several split methods match the mail.
If nil, the first match found will be used."
  :group 'nnmail-split
  :type 'boolean)

(defcustom nnmail-split-fancy-with-parent-ignore-groups nil
  "Regexp that matches group names to be ignored when applying `nnmail-split-fancy-with-parent'.
This can also be a list of regexps."
  :version "22.1"
  :group 'nnmail-split
  :type '(choice (const :tag "none" nil)
                 (regexp :value ".*")
                 (repeat :value (".*") regexp)))

(defcustom nnmail-cache-ignore-groups nil
  "Regexp that matches group names to be ignored when inserting message ids into the cache (`nnmail-cache-insert').
This can also be a list of regexps."
  :version "22.1"
  :group 'nnmail-split
  :type '(choice (const :tag "none" nil)
                 (regexp :value ".*")
                 (repeat :value (".*") regexp)))

;; Added by gord@enci.ucalgary.ca (Gordon Matzigkeit).
(defcustom nnmail-keep-last-article nil
  "If non-nil, nnmail will never delete/move a group's last article.
It can be marked expirable, so it will be deleted when it is no longer last.

You may need to set this variable if other programs are putting
new mail into folder numbers that Gnus has marked as expired."
  :group 'nnmail-procmail
  :group 'nnmail-various
  :type 'boolean)

(defcustom 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/\"."
  :group 'nnmail-files
  :type 'boolean)

(defcustom nnmail-default-file-modes 384
  "Set the mode bits of all new mail files to this integer."
  :group 'nnmail-files
  :type 'integer)

(defcustom 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'."
  :group 'nnmail-expire
  :type '(choice (const immediate)
                 (number :tag "days")
                 (const never)))

(defcustom 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'.

E.g.:

\(setq nnmail-expiry-wait-function
      (lambda (newsgroup)
        (cond ((string-match \"private\" newsgroup) 31)
              ((string-match \"junk\" newsgroup) 1)
              ((string-match \"important\" newsgroup) 'never)
              (t 7))))"
  :group 'nnmail-expire
  :type '(choice (const :tag "nnmail-expiry-wait" nil)
                 (function :format "%v" nnmail-)))

(defcustom nnmail-expiry-target 'delete
  "*Variable that says where expired messages should end up.
The default value is `delete' (which says to delete the messages),
but it can also be a string or a function.  If it is a string, expired
messages end up in that group.  If it is a function, the function is
called in a buffer narrowed to the message in question.  The function
receives one argument, the name of the group the message comes from.
The return value should be `delete' or a group name (a string)."
  :version "21.1"
  :group 'nnmail-expire
  :type '(choice (const delete)
                 function
                 string))

(defcustom nnmail-fancy-expiry-targets nil
  "Determine expiry target based on articles using fancy techniques.

This is a list of (\"HEADER\" \"REGEXP\" \"TARGET\") entries.  If
`nnmail-expiry-target' is set to the function
`nnmail-fancy-expiry-target' and HEADER of the article matches REGEXP,
the message will be expired to a group determined by invoking
`format-time-string' with TARGET used as the format string and the
time extracted from the articles' Date header (if missing the current
time is used).

In the special cases that HEADER is the symbol `to-from', the regexp
will try to match against both the From and the To header.

Example:

\(setq nnmail-fancy-expiry-targets
      '((to-from \"boss\" \"nnfolder:Work\")
        (\"Subject\" \"IMPORTANT\" \"nnfolder:IMPORTANT.%Y.%b\")
        (\"from\" \".*\" \"nnfolder:Archive-%Y\")))

In this case, articles containing the string \"boss\" in the To or the
From header will be expired to the group \"nnfolder:Work\";
articles containing the string \"IMPORTANT\" in the Subject header will
be expired to the group \"nnfolder:IMPORTANT.YYYY.MMM\"; and
everything else will be expired to \"nnfolder:Archive-YYYY\"."
  :version "22.1"
  :group 'nnmail-expire
  :type '(repeat (list (choice :tag "Match against"
                               (string :tag "Header")
                               (const to-from))
                       regexp
                       (string :tag "Target group format string"))))

(defcustom nnmail-cache-accepted-message-ids nil
  "If non-nil, put Message-IDs of Gcc'd articles into the duplicate cache.
If non-nil, also update the cache when copy or move articles."
  :group 'nnmail
  :type 'boolean)

(make-obsolete-variable 'nnmail-spool-file 'mail-sources
                        "Gnus 5.9 (Emacs 22.1)")
;; revision 5.29 / p0-85 / Gnus 5.9
;; Variable removed in No Gnus v0.7

(defcustom nnmail-resplit-incoming nil
  "*If non-nil, re-split incoming procmail sorted mail."
  :group 'nnmail-procmail
  :type 'boolean)

(defcustom nnmail-scan-directory-mail-source-once nil
  "*If non-nil, scan all incoming procmail sorted mails once.
It scans low-level sorted spools even when not required."
  :version "21.1"
  :group 'nnmail-procmail
  :type 'boolean)

(defcustom nnmail-delete-file-function 'delete-file
  "Function called to delete files in some mail backends."
  :group 'nnmail-files
  :type 'function)

(defcustom nnmail-crosspost-link-function
  (if (string-match "windows-nt" (symbol-name system-type))
      'copy-file
    '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."
  :group 'nnmail-files
  :type '(radio (function-item add-name-to-file)
                (function-item copy-file)
                (function :tag "Other")))

(defcustom nnmail-read-incoming-hook
  (if (eq system-type 'windows-nt)
      '(nnheader-ms-strip-cr)
    nil)
  "*Hook that will be run after the incoming mail has been transferred.
The incoming mail is moved from the specified 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.)

E.g.:

\(add-hook 'nnmail-read-incoming-hook
          (lambda ()
            (call-process \"/local/bin/mailsend\" nil nil nil
                          \"read\"
                          ;; The incoming mail box file.
                          (expand-file-name (user-login-name)
                                            rmail-spool-directory))))

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.
            (when (eq (process-status \"display-time\") 'run)
              (display-time-filter display-time-process \"\"))))"
  :group 'nnmail-prepare
  :type 'hook)

(defcustom nnmail-prepare-incoming-hook nil
  "Hook called before treating incoming mail.
The hook is run in a buffer with all the new, incoming mail."
  :group 'nnmail-prepare
  :type 'hook)

(defcustom nnmail-prepare-incoming-header-hook nil
  "Hook called narrowed to the headers of each message.
This can be used to remove excessive spaces (and stuff like
that) from the headers before splitting and saving the messages."
  :group 'nnmail-prepare
  :type 'hook)