Offline address book is used by Office Outlook so that users can locate contact information even when they are not connected to the server. Offline address book works when the Outlook client is configured in cache mode or when it is in offline mode.
In Exchange server 2013 , offline address book is generated by OABGen (Offline Address Book Generation) services, which is running on Mailbox server. It is the OABGen service that identifies the recipients that should be member of offline address book. The offline address book file is created in C:\program Files\Microsoft\Exchange Server\V15\ClientAccess\OAB folder location by default.
Creating a new OAB in Exchange Server 2013
1. Open Exchange Management Shell and enter following command
New-OfflineAddressBook –Name “OAB New” –AdressLists “\Default Global Address List”
Assigning an OAB in Exchange 2013
11. Open Exchange 2013 ECP with Administrator account.
22. Click on “Servers” and select “Databases” select database you want to assign the OAB to
33. Click on “Edit” and Click on “Client Setting”
44. Click on “Browse”
55. Select the Exchange 2013 OAB to assign to the mailbox database
66. Click on “Save”