Getting sendmail to drop email with a specific subject line.

["Steven Jones" <Steven.Jones@vuw.ac.nz>]

We have many bounced email passing htrough our system. What we are
finding is that spammers do an attack on us like suzy@vuw, suzzy@vuw,
sue@vuw etc etc. These get tagged as spam with *****spam***** and as the
user does not exist get bounced our to the false return addresses.  What
I want is a simple filter in Sendmail to drop any outgoing email with
*****spam***** in the subject line.

I have this snippet of code,

F{FullSubjects} -o /etc/mail/subjects_full
F{PartSubjects} -o /etc/mail/subjects_part
HSubject:[TAB]$>CheckSubject

SCheckSubject
R$={FullSubjects}$*[TAB]$: REJECTSUBJECT
R$* $={PartSubjects} $*[TAB]$: REJECTSUBJECT
R$* REJECTSUBJECT $*[TAB]$#error $: "553 Access Denied - MSG may contain
SPAM/WORM/VIRUS/HOAX."

Which rejects based on key words in /etc/mail/subjects_part

Ie *****spam*****

Anyone out there who can edit this for me to simply drop or point at
/dev/null please?  I do not want to bounce the email back, just
blackhole it.

Regards

thing