In my environment I am running 2 Exchange 2007 servers with Mailbox, CA, and Hub Transport Roles, and a single Exchange 2007 with Edge Transport. (The 2 mailbox servers are running on Server 2003, and the Tranport is Server 2008.)
One of the Mailbox servers (ServerA) is all of a sudden delaying the messages that are sent to itself. From that same server I can send a message to an external domain and it will process through the queue immediately. I can send that same message to myself locally, and it will sit in the queue for at least 3 or 4 minutes before it's delivered. Several times messages have stayed in the queue for 30 minutes. At that point I can restart the server, or the Transport service, and most (if not all) of the messages will be sent through. After a minute or two, new messages will again begin to pile up.
Messages that are sent to ServerA from ServerB, or an external domain are having the same result.
Currently there are no errors found that have anything to do with the queue. When I open the queue up there are also no error messages there and the queue shows to be Active. I've also tried the Mail Flow Troubleshooter and it reports that everything is fine.
Any assistance would be greatly appreciated.
On a side note, my worst case scenario is to go ahead and upgrade to Exchange 2010. Since there is no in place upgrade option, I was thinking about converting the current server into a VM using Microsoft's Virtual Machine Manager and doing the upgrade over to the existing hardware. Sounds a little scary to me... Any thoughts?