In general, Outlook will automatically update the Offline Address Book (OAB) for Exchange accounts once every 24 hours.
When it didn’t or when you want to make sure you do have the latest OAB available, you could manually trigger an update from within Outlook as well.
If the update mechanism appears to be broken for you, it could be because of a corruption in your OAB or in your mail profile.
In that case, you can completely reset it by deleting the files making up the OAB or by recreating your mail profile.
We have another server in the wings waiting to be deployed, but we need to address the problem in the meantime. If it does not, then it is the generation or distribution process that is failing.
*** 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.GAL Objects are directly viewable in the Exchange Management Console/Shell and OWA and Microsoft Outlook BUT ONLY IN ONLINE MODE – The GAL will only present objects that have AD Attributes beginning with ms EXCH* (and some others) populated that it uses to filter on.If these attributes are present, then the AD Objects that are Mail-Enabled or Mailbox-Enabled will appear in the GAL – and ultimately the Offline Address Book.Outlook 2011 does not use Exchange Cached mode and directly connects to the Global Address Book (GAL) via LDAP connection.In this case your global address book will update each time Send/Receive is pressed.Instances of mail that is bounced back to the sender may also be fixed.