I'm on Exchange 2007 migration between forest. So far so good but today I found that one of the mailbox which being migrated from source forest having problem to access OWA in target exchange org. When I use management console and right click and select manage full access,I'm receiving below error: Get-MailboxPermission : Cannot get the security descriptor of mailbox "Mailbox GUID" in Exchange mailbox database......... Afte migrated 1200 mailboxes, only this mailbox has problem Please advice

Backup the DB. Delete the user account and restore it with ADRestore. Create a mailbox for the restored object. Use RSG to restore e-mails back to the recreated mailbox. Keep us posted.

what is the root cause?

I found the root cause..while deleted the current mailbox that intact to this AD User. I tried to migrate his mailbox again, result is still failed. When I review the log files, it appeared that this Mailbox Guid which going apply to this user already being used by others user at target domain. My question is why new moved mailbox has same mailboxGUID with existing one?

Hi Suriya25, The mailbox globally unique identifier(GUID) is the most fundamental attribute of a Microsoft Exchange Server mailbox. The value of this attribute is set in the database as the mailbox is created, and it remains the same for the lifetime of the mailbox. For this issue please refer to this document(Preserving Mailbox GUID Values After a Database Move section): Understanding Mailbox GUIDs http://technet.microsoft.com/en-us/library/aa996437(EXCHG.65).aspx Thanks, EvanPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.