[BlueOnyx:05231] Forcing Incoming Mail Through Anti-SPAM Firewall

[Abdul Rashid Abdullah]

What is the best way to insure I force all incoming mail through my
anti-spam firewall?

I have already done the following:

1.  MX Record Points to Anti-SPAM Firewall
2.  Anti-SPAM Firewall points directly to mail server hostname (skipping MX
Record).

I want to make sure no one can send mail directly to the mail server
hostname.  Are there specific configurations I should be making on the
server in the email server settings page?

Regards,

Rashid