I know the more info the btter, so excuse me if this is long.
I did a search and read over 30 threads about what appear to be this same issue. None of that seems to help in my case.
Over the weekend, my Exchange 2003 sp3 server got flooded with mail. Been working on it ever since. The smtp queue currently has almost 6000 queues. Many to a .tw domain. This drops at night and rises back up during the day. We are able to send mail out and recieve mail but it is slow.
So far I have:
-Scanned every PC on the network for spyware
-Created a recipient filter
-Verified I am not an open relay. Cleared "allow all computers to auth" check box.
-Enabled a tar pit
-Tried to flush my queue via MS directions of creating an smtp connector. I gave up on this when the connecter went continued to grow to 30,000 messages. I assumed at that point that the problem was not fixed and stopped it.
-Enabled max logging to look for a 1708 auth message. Never got one.
-Scanned server with malware bytes
-Scanned server with TrendMirco AV
-Ran Windows Update and instaled everything. .Net 3.5 update failed, try that again tonight
-Turned off NDR's (temporarily)
I am SURE I am forgetting something. Especially after spending 24 hours here through Sunday night. I have been all over Simon's site and this and MS.
Are the emails stuck in the queue Postmaster emails or emails to domains which do not exist ?
You need to enable the spam filterings on the exchange server to get this resolved...