A strange issue occured today at one of our clients. We patched the server over night and did the customary reboot. Then this morning, the client reported that one of their customers had received mail that was sent in December!!
Now although I have not 100% identified the problem it seems likely that it was one of two things!
Either mail stuck in the SMTP pickup folder/queue that had been re-processed or, and I think more likely from the searching I have done, mail stuck in the Temp Tables.
So if you happen to be looking for info on this type of problem take a look at these links:
I will continue the troubleshooting tomorrow by looking into the queues and then trying to use MFCMAPI (or its replacement) to inspect the Temp Tables.
If anyone has any other ideas, then let me know!