We are running Unity 4.2 and I am having a problem when adding users to the system. I select the existing Exchange user and then browse to the users mailbox. The problem is that only about half of my Exchange users are showing up. If I leave the search field blank and use a wildcard to see all the users I am only seeing about half of the users I would expect to see. Any ideas why the system doesn't see all my Exchange users? I am using a single Exchange 2003 server.