Offline Outlook Address Book – delays in syncing Outlook and Exchange 2010 – Solved!

When an administrator makes a change in Active Directory/Exchange, why do the changes not appear in the Outlook Offline Address Book immediately?

I found that it may take up to two days for the changes to appear in Outlook.

In Exchange 2010 it takes even longer to synchronize the changes in the OAB than Exchange 2007.  After the OAB is updated, which by default is once a day, it may take up to 8hrs for the OAB to be available to the client. The reason is that the OAB is generated in the MAILBOX role and needs to be copied to the CLIENT ACCESS role. The CLIENT ACCESS role checks for changes every 8 hrs. On top of these delays, if a client does not close/open his or her Outlook, it can take even longer for a change to take place.

If you want the changes to appear in your Outlook Address Book right away, you need to do the following:

1. Make a change or changes to the OAB. An administrator can do this by going to their Exchange server, and open the Exchange Management Console. Drill down from Microsoft Exchange to ->Microsoft Exchange On-Premises ->Recipient Configuration -> Mailbox. Right-click on the user in which you want to make changes or add another SMTP address. Add or Edit the addresses, etc.
2. Manually update OAB  in the Exchange server. Go to the Exchange Management Console -> Microsoft Exchange -> Microsoft Exchange On-Premises -> Organization Configuration -> Right-Click on Mailbox and choose Properties. Click on the Offline Address Book tab. Right-click on the default offline address book and choose Update. 
3. Restart Microsoft Exchange File Distribution service. On the Exchange server, go to Start -> Run -> type in Services.msc and hit Enter/OK. Browse to the Microsoft Exchange File Distribution service, right-click on the service and click Restart.
4. You may need to Sync the Domain Controllers between sites (in a multi-site environment).
5. Download the OAB in Outlook. Open Outlook on the client that wants the change. Go to the File tab/menu. Click on the Account Settings button and then click on Download Address Book…

Otherwise, the process may take up to 56  hrs (24hrs to generate OAB, 8 hrs to update the CLIENT ACCESS, and 24 hrs to update Outlook).