mt6-mailfilter.txt

SHELL="/bin/sh"
import EXT
import HOST
VHOME=`pwd`
TIMESTAMP=`date "+%b %d %H:%M:%S"`

##
#  title:  mailfilter-site
#  author: Matt Simerson
#  version 3.1
#
#  Usage: Install this file in /etc/mailfilter.
#
#  Create a .qmail file in each users Maildir as follows:
#  echo "| /usr/local/bin/maildrop /etc/mailfilter" > ~vpopmail/domains/example.com/user/.qmail
#
#  Qmailadmin v1.0.26 or higher does that automatically with
#  options --enable-modify-spam and --enable-spam-command.
#
# Environment Variables from qmail-local:
#  SENDER    is  the envelope sender address
#  NEWSENDER is the forwarding envelope sender address
#  RECIPIENT is the envelope recipient address, local@domain
#  USER  is user
#  HOME  is your home directory
#  HOST  is the domain part of the recipient address
#  LOCAL is the local part
#  EXT   is  the  address extension, ext.
#  HOST2 is the portion of HOST preceding the last dot
#  HOST3 is the portion of HOST preceding the second-to-last dot
#  HOST4 is the portion of HOST preceding the third-to-last dot
#  EXT2  is the portion of EXT following the first dash
#  EXT3  is the portion following the second dash;
#  EXT4  is the portion following the third dash.
#  DEFAULT is  the  portion corresponding to the default part of the .qmail-... file name
#  DEFAULT is not set if the file name does not end with default
#  DTLINE  and  RPLINE are the usual Delivered-To and Return-Path lines, including newlines
#
# qmail-local will call maildrop. The exit codes that qmail-local understands are:
#     0 - delivery is complete
#   111 - temporary error
#   xxx - unknown failure
##
#logfile "/var/log/mail/maildrop.log"
log "$TIMESTAMP - BEGIN maildrop processing for $EXT@$HOST ==="

# sysadmin blunders can cause EXT or HOST to be unset. 
# test and make assure things are not too messed up.
#
# By exiting with error 111, the error will be logged, giving an admin
# the chance to notice and fix the problem before the message bounces.

if ( $EXT eq "" )
{
        log "  FAILURE: EXT is not a valid value"
        log "=== END ===  $EXT@$HOST failure (EXT variable not imported)"
        EXITCODE=111
        exit
}

if ( $HOST eq "" )
{
        log "  FAILURE: HOST is not a valid value"
        log "=== END ===  $EXT@$HOST failure (HOST variable not imported)"
        EXITCODE=111
        exit
}

##
# Include user rules, for overrides of the the sitewide mailfilter
#
# this is also the "suggested" way to set individual values
# for maildrop such as quota.
##

`test -r $VHOME/.mailfilter`
if( $RETURNCODE == 0 )
{
        log "   including $VHOME/.mailfilter"
        exception {
                include $VHOME/.mailfilter
        }
}

##
# if it does not exist, create the maildirsize file 
# (can also be done via "deliverquota user@dom.com 10MS,1000C)
##

`test -e $VHOME/Maildir/maildirsize`
if( $RETURNCODE == 1)
{
        VUSERINFO="/usr/local/vpopmail/bin/vuserinfo"
        `test -x $VUSERINFO`
        if ( $RETURNCODE == 0)
        {
                log "   creating $VHOME/Maildir/maildirsize for quotas"
                `$VUSERINFO -Q $EXT@$HOST`

                `test -s "$VHOME/Maildir/maildirsize"`
                if ( $RETURNCODE == 0 )
                {
                        `/usr/sbin/chown vpopmail:vchkpw $VHOME/Maildir/maildirsize`
                                `/bin/chmod 640 $VHOME/Maildir/maildirsize`
                }
        }
        else
        {
                log "   WARNING: cannot find vuserinfo! Please edit mailfilter"
        }
}

##
# Set MAILDIRQUOTA. If not set, maildrop and deliverquota
# will not enforce quotas for message delivery.
##

`test -e $VHOME/Maildir/maildirsize`
if( $RETURNCODE == 0)
{
        MAILDIRQUOTA=`/usr/bin/head -n1 $VHOME/Maildir/maildirsize`
}

# if the user does not have a Spam folder, create it.

`test -d $VHOME/Maildir/.Spam`
if( $RETURNCODE == 1 )
{

    MAILDIRMAKE="/usr/local/bin/maildirmake"
    `test -x $MAILDIRMAKE`
    if ( $RETURNCODE == 1 )
    {
        MAILDIRMAKE="/usr/local/bin/maildrop-maildirmake"
        `test -x $MAILDIRMAKE`
    }

    if ( $RETURNCODE == 1 )
    {
        log "   WARNING: no maildirmake!"
    }
    else
    {
        log "   creating $VHOME/Maildir/.Spam "
        `$MAILDIRMAKE -f Spam $VHOME/Maildir`
    }
}

##
# The message should be tagged, lets bag it.
##
# HAM:  X-Spam-Status: No, score=-2.6 required=5.0
# SPAM: X-Spam-Status: Yes, score=8.9 required=5.0
#
# Note: SA < 3.0 uses "hits" instead of "score"
#
# if ( /^X-Spam-Status: *Yes/)  # test if spam status is yes
# The following regexp matches any spam message and sets the
# variable $MATCH2 to the spam score.

if ( /X-Spam-Status: Yes/:h)
{
    if ( /X-Spam-Status: Yes, (hits|score)=([\d\.\-]+)\s/:h)
    {
        # if the message scored a 12 or higher, then there is no point in
        # keeping it around. SpamAssassin already knows it as spam, and
        # has already "autolearned" from it if you have that enabled. The
        # end user likely does not want it. If you wanted to cc it, or
        # deliver it elsewhere for inclusion in a spam corpus, you could
        # easily do so with a cc or xfilter command

        if ( $MATCH2 >= 12 )   # from Adam Senuik post to mail-toasters
        {
            log "   SPAM: score $MATCH2 exceeds 12: nuking message!"
            log "=== END === $EXT@$HOST success (discarded)"
            EXITCODE=0
            exit
        }
        log "   SPAM: score $MATCH2: delivering to $VHOME/Maildir/.Spam"
        log "=== END ===  $EXT@$HOST success"
        exception {
            to "$VHOME/Maildir/.Spam"
        }
    }
    else
    {
        log "   SpamAssassin regexp match error!"
    }
}

if ( /^X-Spam-Status: No, (score|hits)=([\d\.\-]+)\s/:h)
{
    log "   message is SA clean ($MATCH2)"
}

##
# Include any other rules that the user might have from
# sqwebmail or other compatible program
##

`test -r $VHOME/Maildir/.mailfilter`
if( $RETURNCODE == 0 )
{
        log "   including $VHOME/Maildir/.mailfilter"
        exception {
                include $VHOME/Maildir/.mailfilter
        }
}

`test -r $VHOME/Maildir/mailfilter`
if( $RETURNCODE == 0 )
{
        log "   including $VHOME/Maildir/mailfilter"
        exception {
                include $VHOME/Maildir/mailfilter
        }
}

log "   delivering to $VHOME/Maildir"

# make sure the deliverquota binary exists and is executable
# if not, then we cannot enforce quotas. If we do not check
# and the binary is missing, maildrop silently discards mail.

DELIVERQUOTA="/usr/local/bin/deliverquota"
`test -x $DELIVERQUOTA`
if ( $RETURNCODE == 1 )
{
    DELIVERQUOTA="/usr/local/bin/maildrop-deliverquota"
    `test -x $DELIVERQUOTA`
}

if ( $RETURNCODE == 1 )
{
    log "   WARNING: no deliverquota!"
    log "=== END ===  $EXT@$HOST success"
    exception {
        to "$VHOME/Maildir"
    }
}
else
{
    exception {
        xfilter "$DELIVERQUOTA -w 90 $VHOME/Maildir"
    }

    ##
    # check to make sure the message was delivered
    # returncode 77 means that out maildir was overquota - bounce mail
    ##
    if( $RETURNCODE == 77)
    {
        #log "   BOUNCED: bouncesaying '$EXT@$HOST is over quota'"
        log "=== END ===  $EXT@$HOST  bounced"
        to "|/var/qmail/bin/bouncesaying '$EXT@$HOST is over quota'"
    }
    else
    {
        log "=== END ===  $EXT@$HOST  success (quota)"
        EXITCODE=0
        exit
    }
}

log "WARNING: This message should never be printed!"