Procmail

MAILDIR=$HOME/Maildir/
DEFAULT=$MAILDIR
#VERBOSE=yes
LOGFILE=$HOME/procmail.log

# pres SPAMASSASIN jen male zpravy
:0fw
* < 131072
* !^Resend: Yes
| /usr/bin/spamc

:0
* ^X-Spam-Status: Yes
* ^X-Spam-Flag: YES
* !^Resend: Yes
{
    :0f
    | formail -A "Resend: Yes"
    :0f
    ! spam@gym-cl.cz
}