I have a customer who sorts his email into one of two subfolders directly below his Inbox. Lately he's been having an issue where old mail will reappear in his Inbox. There have been at least four occurrences of the problem. We use an Exchange 2003 Enterprise server (on Windows 2003 Server Enterprise, both on SP1). He normally uses an email client called Mulberry, but after the first instance of this problem he stopped using Mulberry and started using Outlook 2003. As this has occurred under both email clients, we determined the client is not the issue. He also has a Blackberry 7130e, however we don't believe this problem is Blackberry specific (I have 60 other Blackberry users that do not have this problem).
It's important to note the reappearance of these emails is a true reappearance (ie: not duplicates) - when they reappear in the Inbox they no longer appear in the folders to which they had been filed originally.
The first time this happened he was using Mulberry (email client) and 348 previously filed emails reappeared in the Inbox. These were emails that were filed a month ago or longer. Subsequent occurrences involved 20 emails, 78 emails, and the last one, 2 emails all of which had been filed for multiple days before the mysterious reappearance. On one of those instances he had stopped using Mulberry, so it occurred while using Outlook 2003. We also had a theory at one point that it might be related to the BlackBerry, because one occurrence happened shortly after he did a manual synch (via Intellisync) with his Outlook Contacts and Notes, but on subsequent occurrences he hadn't done an Intellisync in quite a while, seemingly ruling out that theory. He never files emails using his Blackberry, only when using an email client (ie: Mulberry) and he uses the wireless synch for email so his email is always synched with his Blackberry.
My personal opinion is that the culprit is the Exchange Server, which is the one common thread amongst Mulberry, Outlook, and BlackBerry, however I haven't been able to find a solution anywhere. I prefer not to delete/recreate this person's mailbox if I don't have to, so any suggestions are welcome.
Thanks in advance for your assitance.