Sendmail Question

[Mike Kercher]

I am acting as the only MX for a number of domains in order to scan their
email for viruses and content and then forward on via mailertable to their
final destination.

The problem I'm having is that spammers have begun using their domain name
for sending spam...thus all of the bounces to non-existent email addresses
comes back through me and then finally to postmaster at domain.com as
undeliverable.

How can I drop these non-existent addresses at my server when they are, at
best, randomly generated?  There are only 5 valid email addresses at this
domain...I need to drop the rest.

I've tried adding entries to /etc/mail/access like such:

@domain.com			REJECT
gooduser at domain.com	OK
gooduser2 at domain.com	OK

to no avail.  domain.com is listed in my /etc/mail/relay-domains and NOT
/etc/mail/local-host-names.  Any help would be appreciated.

Mike