This is a follow on question for solution 21433111. We are experiencing a similar problem. The solution to 21433111 is as follows :
"I guess you are using mimesweeper as SMTP Relay server. Is your relay server configured to allow relaying from exchange 2003 cluster server ?. Go to relay settings of your SMTP relay server and add the IP address of your e2k3 server in allow list"
We are new to MIMESWEEPER and do not know how to do this. Can anyone help please?