Mail Backend Variables
----------------------

   These variables are (for the most part) pertinent to all the various
mail backends.

`nnmail-read-incoming-hook'
     The mail backends all call this hook after reading new mail.  You
     can use this hook to notify any mail watch programs, if you want
     to.

`nnmail-spool-file'
     The backends will look for new mail in this file.  If this
     variable is `nil', the mail backends will never attempt to fetch
     mail by themselves.  If you are using a POP mail server and your
     name is `larsi', you should set this variable to `po:larsi'.  If
     your name is not `larsi', you should probably modify that
     slightly, but you may have guessed that already, you smart &
     handsome devil!  You can also set this variable to `pop', and Gnus
     will try to figure out the POP mail string by itself.  In any
     case, Gnus will call `movemail' which will contact the POP server
     named in the `MAILHOST' environment variable.  If the POP server
     needs a password, you can either set
     `nnmail-pop-password-required' to `t' and be prompted for the
     password, or set `nnmail-pop-password' to the password itself.

     When you use a mail backend, Gnus will slurp all your mail from
     your inbox and plonk it down in your home directory.  Gnus doesn't
     move any mail if you're not using a mail backend--you have to do a
     lot of magic invocations first.  At the time when you have
     finished drawing the pentagram, lightened the candles, and
     sacrificed the goat, you really shouldn't be too surprised when
     Gnus moves your mail.

`nnmail-use-procmail'
     If non-`nil', the mail backends will look in
     `nnmail-procmail-directory' for incoming mail.  All the files in
     that directory that have names ending in `nnmail-procmail-suffix'
     will be considered incoming mailboxes, and will be searched for new
     mail.

`nnmail-crash-box'
     When the mail backends read a spool file, it is first moved to this
     file, which is `~/.gnus-crash-box' by default.  If this file
     already exists, it will always be read (and incorporated) before
     any other spool files.

`nnmail-prepare-incoming-hook'
     This is run in a buffer that holds all the new incoming mail, and
     can be used for, well, anything, really.

`nnmail-pre-get-new-mail-hook'
`nnmail-post-get-new-mail-hook'
     These are two useful hooks executed when treating new incoming
     mail--`nnmail-pre-get-new-mail-hook' (is called just before
     starting to handle the new mail) and
     `nnmail-post-get-new-mail-hook' (is called when the mail handling
     is done).  Here's and example of using these two hooks to change
     the default file modes the new mail files get:

          (add-hook 'gnus-pre-get-new-mail-hook
                    (lambda () (set-default-file-modes 511)))
          
          (add-hook 'gnus-post-get-new-mail-hook
                    (lambda () (set-default-file-modes 551)))

`nnmail-tmp-directory'
     This variable says where to move the incoming mail to while
     processing it.  This is usually done in the same directory that
     the mail backend inhabits (i.e., `~/Mail/'), but if this variable
     is non-`nil', it will be used instead.

`nnmail-movemail-program'
     This program is executed to move mail from the user's inbox to her
     home directory.  The default is `movemail'.

`nnmail-delete-incoming'
     If non-`nil', the mail backends will delete the temporary incoming
     file after splitting mail into the proper groups.  This is `nil' by
     default for reasons of security.

`nnmail-use-long-file-names'
     If non-`nil', the mail backends will use long file and directory
     names.  Groups like `mail.misc' will end up in directories like
     `mail.misc/'.  If it is `nil', the same group will end up in
     `mail/misc/'.

`nnmail-delete-file-function'
     Function called to delete files.  It is `delete-file' by default.