[Mimedefang] This mail's for you... NOT!

[Shively, Michael @ FRE]

I'm new to the list (about 4 days new).
I am running Fedora with sendmail, spamassassin and mimedefang as a mail
gateway to my Exchange Server.
I am excepting mail for a single domain and I have about 150 users(mail
boxes).

Everything is working but I have a few concerns.

I find messages in my outgoing queue for sendmail but the messages are
addresses to other domains. Luckily I decided to use my Exchange Server as
the Outgoing mail server and I configured my 3rd party firewall to deny the
Fedora box access to port 25 outgoing.
So, I am FaIrLy CeRtAiN that I am not being used as a relay.
How do I prevent my Fedora box from accepting mail for other domains?
(FYI: I receive approx 1500 mail messages per day (90% spam) LOL)
(FYI: Only a few (1-5) messages are accepted for other domains per day)

Also,
Most of the spam messages that I receive are addresses to non-existing
users... Mailing list I guess...  Can I setup a way to accept mail for only
a list of e-mail addresses?
It seems like a shame that spamassassin and mimedefang have to work so hard
scanning messages that are not even sent to a real recipient.

Thanks,
Michael
New to Linux but learning fast!

Visit http://www.mimedefang.org and http://www.canit.ca
MIMEDefang mailing list
MIMEDefang at lists.roaringpenguin.com
http://lists.roaringpenguin.com/mailman/listinfo/mimedefang