My backend emails server processes about 50,000 emails a day and about 5 get stuck in the "messages awaiting directory lookup" queue. All the messages that get stuck are 3 to 10 megs in size. I have checked the size settings everywhere I can and don't see any limits close to this and some emails this size are getting through ok. My other backend server does not seem to be affected. I am running symantec AV and GFI tools on all my Exchange servers.
I have tried to disable Symantec and the queue does not seem to clear.
Can someone tell me where to look to try to make sure the messages flow right through?