E2K SMTP virtual server mailflow slow

From: Joe Mancuso (jmancuso_at_umaryland.edu.NO-SPAM)
Date: 05/04/04 

Date: Tue, 4 May 2004 12:21:01 -0700

The default SMTP virtual server on my Exchange 2K with SP3 has been in operation for many months now. Recently, messages for external domains will suddenly begin to queue up. Eventually messages will begin to trickle out to their intended destination. Then again suddenly, message flow will return to normal and be delivered without delay.

During times of delay, if I telnet to port 25 of one of the systems trying to be contacted, the connection will fail. If I do it again, it will work. When I raise the EXCHANGE TRANSPORT values to MAX, I'll sometimes receive an Event ID: 4000 with the message "connection dropped by the remote host."

I've looked everywhere on the net and still can not seem to get a handle on what is causing this intermittent issue. Thoughts?