Save the following script to a file to your Exchange Server then execut using the Exchange Management Shell – and then follow the prompts.
Remember this script will set the OAB for all Mailbox Databases.
$OABs = Get-OfflineAddressBook
$Count = 0
Foreach($Oab in $OABs){
Write-Host $Count "." $Oab.Name
$Count++
}
$Choice = Read-Host "Please choose"
Get-MailboxDatabase | Set-MailboxDatabase -OfflineAddressBook $Oabs[$Choice]
