


Get-offlineaddressbook | update-offlineaddressbook Set the mailbox database to use that new OAB: Set-MailboxDatabase "Mailbox Database01" -OfflineAddressBook "OAB_Contoso" New-OfflineAddressBook -Name "OAB_Contoso" -AddressLists "\Default Global Address List" Try creating a new Offline Address Book, its real simple and easy to test:

Get-Mailbox -Arbitration | where | ft name,database If this is DAG, move the database that holds the OAB arbitration mailbox to another server and restart the Mailbox Assistant service on that server and see if new OAB files are generated Restart the Mailbox Assistant service on the server and see if the files are regenerated and that whenchanged date is updated and try to download the OAB from Outlook.
