I had some users that had a problem with the Advanced Search. Some of their searches incorrectly returned no results. Going through the procedure in the KB below corrected the problem:
Shouldn't mailboxes periodically get indexed? What would cause a mailbox's index to become outdated? Could someone provide an example? Also, our index queue is not very busy. The queue averages 1 or 2 users.
Thought I would check here before opening a ticket.
We're running Enterprise Version 14.4.5801.