Filtering with Entourage
From ITS Wiki
"All of my email is disappearing from my Inbox!"
Although I'm not quite sure how, Entourage's Mailing List Manager Feature has been accidentally turned on by more than one person. The default rule seems to take all, or nearly all, email that comes to the Inbox under the Centre Exchange account and move it, usually to the local Inbox on the computer. Uncheck all of the rules listed in the MLM to fix this problem.

