Answer: When we update, remove or add a new user to Exchange Server, Exchange server will distribute the address book changes to our Outlook client based on the default address book refresh settings.
If you need to push the address book updates immediately to all Outlook Clients use the following steps:
Open EMC -> Organization Configuration -> Mailbox -> Address List Tab
Right Click on the Address Book you need to update and click Apply.
Select when you want to apply the Address Book and click on next.
Click on finish.