NAME

    The dovecot antispam pugin.

DESCRIPTION

    The dovecot antispam plugin watches a defined spam folder (defaults to
    "SPAM"). It works together with a spam system that classifies each
    message as it is delivered. When the message is classified as spam, it
    shall be delivered to the spam folder, otherwise via the regular
    filtering file the user may have (maildrop, sieve, ...). Now the user
    has everything classified as spam in the special spam folder, everything
    else where it should be sorted to.

    This is not enough because our spam scanner needs training. We'll
    occasionally have false positives and false negatives. Now this is the
    point where the dovecot antispam plugin comes into play. Instead of
    moving mail into special folders or forwarding them to special mail
    addresses for retraining, the plugin offers two actions for the user:
       1. moving mail out of the SPAM folder and
       2. moving mail into the SPAM folder.

    The dovecot plugin watches these actions (and additionally prohibits
    APPENDs to the SPAM folder, more for technical reasons than others) and
    tells the spam classifier that it made an error and needs to re-classify
    the message (as spam/not spam depending on which way it was moved.)

    The advantage of this approach is that the mail ends up in the right
    target folder directly and needs not be touched twice.

INSTALLATION

    First copy the 'defconfig' file to '.config' and edit it as necessary.
    You need to have the dovecot headers installed and possibly other things
    depending on the backend you choose. Then simply run 'make'.

    Copy the plugin antispam.so to your dovecot imap plugin directory.
    Depending on your installation it could be /usr/lib/dovecot/modules/imap/
    or wherever you have it configured (look for the mail_plugin_dir
    configuration directive.)

    Open your dovecot configuration file (usually /etc/dovecot/dovecot.conf)
    and add the antispam plugin to the imap protocol section:

    protocol imap {
      mail_plugins = antispam
      # mail_plugin_dir = /usr/lib/dovecot/modules/imap
    }

CONFIGURATION

    Aside from the build-configuration done in the '.config' file, you have
    the following run-time options (shown along with the default):

    plugin {
        ##################
        # GENERIC OPTIONS

        # mail signature (used with any backend requiring a signature)
        antispam_signature = X-DSPAM-Signature

        # semicolon-separated list of Trash folders (default unset i.e. none)
        # antispam_trash =
        # antispam_trash = trash;Trash;Deleted Items

        # semicolon-separarted list of spam folders
        antispam_spam = SPAM

        ###########################
        # BACKEND SPECIFIC OPTIONS
        #

        # dspam-exec plugin:

        # dspam binary
        antispam_dspam_binary = /usr/bin/dspam

        # semicolon-separated list of extra arguments to dspam
        # (default unset i.e. none)
        # antispam_dspam_args =
        # antispam_dspam_args = --user;%u  # % expansion done by dovecot
        # antispam_dspam_args = --mode=teft
    }

AUTHORS

    Johannes Berg, Frank Cusack, Benedikt Boehm, Andreas Schneider