They call IT to report this problem. The administrator checks but can’t find anything. The user account for this person has been set up correctly, the person has logged in and is receiving and sending e-mail successfully.
Not really knowing what else to do the admin forces Exchange to rebuild the offline address book, and then forces Outlook to download it again completely yet nothing changes.
It’s a mystery; you have recipients not showing in address lists and perhaps sometimes these people did once show in the GAL but now they have disappeared!
This is something that has happened at least once to every Exchange administrator I know, and across both Exchange 2003 and Exchange 2007.
It happened to me. Fortunately, I figured it out! Here’s my solution.