After doing a migration from Microsoft Exchange 2013 to Exchange 2016 I noticed that my Offline Address Book (OAB) wasn’t being made available to Outlook clients.
When trying to perform a manual download (Send and Receive -> Download Address Book), it wasn’t in the list. Also when using the “Test EMail AutoConfiguration..” (by holding CTRL and right click on Outlook System Tray icon) to examine the AutoDiscover information, there was no OAB URL (OABUrl in XML) being sent to the clients.
I spent 3 hours trying to find out why this was happening (I assumed it was configuration and/or IIS authentication related). All my virtual directories and URLs were fine, and the OAB was being generated fine without any issues. It simply wasn’t being passed to Outlook clients. I couldn’t find any references of this occurring to other users.
I finally discovered that the “WebDistributionEnabled” configuration flag was marked to False, when it needs to be marked as True. This flag when set to true, allows it to be distributed (Note/Fun Fact: There’s a separate and different flag for older Exchange versions where the OAB is inside of the Public Folder Store). There’s also a different flag “GlobalWebDistributionEnabled”, which is recommended to be enabled as well on Exchange 2016. When setting this second flag to True, it also sets the first one above to True as well.
To fix it we’ll use Exchange PowerShell:
Let’s find the name of your Offline Address Book by running the command below:
Now let’s set the “GlobalWebDistributionEnabled” flag to True using this next command:
Set-OfflineAddressBook -Identity “Default Offline Address Book (Ex2016)” -GlobalWebDistributionEnabled $true
And finally let’s confirm to make sure the changes take effect and look for the values of “GlobalWebDistributionEnabled” and “WebDistributionEnabled” using the command:
Get-OfflineAddressBook | fl
After making the above changes I recommend issuing an “iisreset” or restarting your Exchange Server. There will also be a delay where you’ll need to wait for your Outlook clients to refresh their autodiscover configuration. You can run the “Test Email AutoConfiguration…” to see if the OAB is now being passed to your clients.