procmail

LOGFILE="/var/log/mail/$USER.log"
DELIVERMAIL="/usr/sbin/cyrdeliver"
BACKUP="$DELIVERMAIL -e -a $USER -m user.$USER.Backup"
SPAMIT="$DELIVERMAIL -e -a $USER -m user.$USER.SPAM"
IMAP="$DELIVERMAIL -e -a $USER -m user.$USER"

:0 c
| $BACKUP

:0
* ^subject: This is spam
| $SPAMIT

:0 w 
| $IMAP

:0 w
{
EXITCODE=$?
HOST
}