[Mimedefang] Busy Mail Server

[Ray Parish]

I have 2 Servers (Pentium Xeon 2.8ghz servers, 2 gig ram). I have mimedefang only rewriting the subject line to add "Potential SPAM::"

I have 

MX_SLAVE_DELAY=1
MX_MINIMUM=20
MX_MAXIMUM=40


So that being said, here is the scoop.

I have about 95 domains hitting these 2 boxes, then scanned and then sent off to my Exchange 2000 Backend Enviroment.

I get about 160 concurrent connections to one box and the load is so high, it is not able to accept any more connections. Then I start getting "connection timedout" to my Exchange enviroment. 
This of course causes the mail to start Queueing up on the MIMEDefang server.

OS is Fedora.

Anyone have some suggestions?

Thanks