One of the Address Books that Outlook keeps is the Global Address List, which is a comprehensive list of every “mailbox-enabled or mail-enabled object in an Active Directory forest that has Exchange installed” (Source: Microsoft).
Microsoft also keeps an offline version of this address list, and this can be accessed when you are not connected to Exchange. You’ll want to keep this address list, or address book, updated in the event that you need it.
To download changes to your Offline Global Address List, open Outlook. Under “Send / Receive”, select “Send/Receive Groups”, then “Download Address Book”:
Select “Download changes since last Send/Receive”, then choose the address book you want to update:
Click OK.
Thank you! Worked for me!