In ups.com,
typed:
I have a user that clams that all his emails just deleted them selves.
I went and looked at the deleted folder and there is nothing there.
All the settings in outlook appear to be the normal settings. I
couldn't find a rule that was set to delete any email and auto
archiving is set for 14 days and it prompts before it deletes. We are
running an Exchange server 2k3. Has anyone else herd of this problem?
If so what else could cause the deletion and how can I fix it?

Does he have any computer/device checking this mailbox via POP3?

Do you have deleted item retention (DIRT) set on your server? If so, enable
the DumpsterAlwaysOn reghack (link below) and look in the Recover Deleted
Items folder in his mailbox in Outlook.

http://support.microsoft.com/default...b;EN-US;886205