Cumulative Update 5 (CU5) for Exchange Server 2013 will be released soon TM , but before that happens, I wanted to make you aware of a behavior change in the Offline Address Book that is shipping in ...
Updated Jul 01, 2019
Version 2.0
Blog Post
@ActionXP - We agree, the current E2013 design (CU1-CU4) is not ideal. That's why we are changing the design, bringing it back to a similar design that existed in prior releases. Unfortunately, changing the design requires some customers to have to experience
a full OAB download. Out of the box, Exchange 2013 only creates a single OAB generation mailbox. If you or any customer is operating in that configuration, CU5 WILL NOT introduce a full OAB download, until you create additional OAB generation mailboxes and
assign new OABs. The only customers affected by the CU5 change are customers that have multiple OAB generation mailboxes today as they will experience full OAB downloads to get to the desired CU5 state.