You may encounter an issue stating that the System Attendant Service is not running or you do not have permission. Make sure you are running the Exchange Management Shell as Administrator and 2. *note* The Service is named “Microsoft Exchange System Attendant”.
The Outlook Client failed to download an updated copy of the Offline Address Book because the services have stopped functioning.
Then suddenly, when cached mode was on, the GAL was populated!
However, when I closed the address book and opened it again just to make sure I wasn't dreaming, the GAL was blank...again! Some of our users were not able to get to the GAL properly.
This can occur even though no errors are present within the OAB rebuild process.
Once again, I use the Outlook connectivity test feature again, click "Connection Status", click "Reconnect", and open address book, and presto..GAL is populated. The issue might be as simple as changing the radio button setting on the Address Book window to "Name only".
This can happen after a long period of use with outlook and happens for no apparent reason.
To get the OAM to immediately generate run the following command: Update-Offline Addressbook “name of offline address book”.
When that control is set to "More columns" instead it causes the contents of the list to be blank until a search is performed.
This document seeks to address and clarify the small misunderstanding surrounding the GAL (Global Address List) and the OAB (Offline Address Book).
*** NOTE: The GAL is essentially a real-time / online representation of AD Objects that are Mail Enabled for Microsoft Exchange *** The GAL contains information for all email enabled users, Distribution Groups, and Shared Mailboxes and Exchange Resource Mailboxes.