I used to get this error all the time, plus if I left the messages on the server, it would download them more than once, it failed to recognize that the message had already been downloaded. However both problems have gone completely and all mail activity is working perfectly since I changed over from 5.6 to 6.0 (with all the updates of course) Thanks for pointing out the Microsoft article though as I do have a few friends that are still on 5.6 that suffer the same issue.