We are running a single Exchange server, in an active/passive cluster. In the past two days all outgoing smtp traffic has been at a standstill. Messages simply sit in their que in a retry state until they expire. I have noticed that if i fail over from sever1 to server2 smtp flows for about a min or so. this is really startign to cause problems and needs to get fixed. I have called micorsoft to no avail, so i am at the feet of the experts here. we have made no changes to the system in the past few months.