# Global maildrop filter file (used on Debian)
# For use with Postfix/Courier IMAP/Amavisd-new virtual mailbox domains.
#
# This maildroprc automagically creates a Spam folder for the recipient
# and places spam there. It also subscibes the recipient to the folder.
#
# Example maildir: /var/vmail/example.com/user/
# Configure 'plus addressing' in amavisd-new and Postfix in order to deliver
# spam to user+spam@example.com. In main.cf:
# recipient_delimiter = +
#
# in amavisd.conf:
# $recipient_delimiter = '+';
# @addr_extension_spam_maps = ('spam');
# 
# Remember that 'plus addressing' occurs at tag2_level, not kill_level. kill_level needs
# to be sufficiently high in order to allow some mail at tag2_level or greater to be 
# delivered to the recipient. Also be aware: if you create virtual aliases designed to 
# send mail to remote domains, either those remote domains must also support 
# 'plus addressing' or you will need to create additional aliases to remove +spam:
#
# user+spam@example.org user@example.org
#
# This means address rewriting cannot be disabled on the amavisd-new reinjection port.
#
# Also in main.cf:
# virtual_transport = maildrop
# maildrop_destination_concurrency_limit = 2
# maildrop_destination_recipient_limit = 1
#
# and in master.cf:
#
# maildrop  unix  -       n       n       -       -       pipe
#  flags=DRhu user=vmail:daemon argv=/usr/bin/maildrop -w 90 -d ${user}@${nexthop}
#  ${extension} ${recipient} ${user} ${nexthop}
#
# /var/log/maildroprc.log needs to exist and owned by vmail:vmail and
# a logrotate script needs to be created.
#

HOME_DIR="/var/vmail"
logfile "/var/log/maildroprc.log"
EXTENSION="$1"
RECIPIENT=tolower("$2")
USER="$3"
HOST="$4"
SENDER="$5"

if ( $EXTENSION eq "spam" )
{
   # Change 'spam' to 'Spam' since folder names are typically capitalized
   EXTENSION = "Spam"
   
   # Autocreate extension maildir
   #
   # See if the user exists
   `test -e $HOME_DIR/$HOST/$USER`
   #log "Testing for $HOME_DIR/$HOST/$USER subdirectory: result=$RETURNCODE"
        
   # Only continue if user is valid
   if ( $RETURNCODE == 0 )
   {      
      # See if the spam directory already exists
      `test -e $HOME_DIR/$HOST/$USER/.$EXTENSION`
      #log "Testing for $EXTENSION subdirectory: result=$RETURNCODE"

      if ( $RETURNCODE != 0 ) # spam directory does not exist - so we create it
      {
      
         # Create the subdirectory
         `maildirmake -f $EXTENSION $HOME_DIR/$HOST/$USER`
         log "Ran \"maildirmake -f $EXTENSION $HOME_DIR/$HOST/$USER\""
        
         # Auto-subscribe the subdirectory
         `if ! grep -q INBOX.$EXTENSION $HOME_DIR/$HOST/$USER/courierimapsubscribed; then echo INBOX.$EXTENSION >> $HOME_DIR/$HOST/$USER/courierimapsubscribed; fi`
      
         # Set permissions on the mailbox
         `chmod -R 0700 $HOME_DIR/$HOST/$USER`
         log " Ran \"chmod -R 0700 $HOME_DIR/$HOST/$USER\""        
      }
        
      # Deliver the message to the mailbox
      exception {
      # for those who unsubscribed themselves - subscribe them
     `if ! grep -q INBOX.$EXTENSION $HOME_DIR/$HOST/$USER/courierimapsubscribed; then echo INBOX.$EXTENSION >> $HOME_DIR/$HOST/$USER/courierimapsubscribed; fi`
      to "$HOME_DIR/$HOST/$USER/.$EXTENSION"
      }
   }
}