After an unswitched target mailbox was moved, mail redirection stops working. For example, when a switched user sends mail to unswitched user, the mail stays in the target mailbox and is not getting redirected to the source.
Move mailbox process clears the targetAddress attribute that Migration Manager is using for redirection.
This redirection process is detailed in solution SOL14915 - How does the Mailbox redirection work in Quest Migration Manager for Exchange? -https://support.quest.com/SUPPORT/index?page=solution&id=SOL14915
According to Microsoft KB article ID 297393 "How To Pro-grammatically Move an Exchange Mailbox Using CDOEXM in Visual C++":http://support.microsoft.com/?kbid=297393
The IMailboxStore method, MoveMailbox, performs two sets of tasks as follows:
- Directory-related tasks on the user object
- Updates the homeMTA attribute.
- Updates the store's distinguished name on the homeMDB attribute.
- Deletes the target e-mail address for the user object stored in the targetAddress attribute. This will be updated by the Recipient Update Service (RUS) when it runs against this user.
This means that if the unused mailbox (source mailbox for switched user or target mailbox for unswitched user) is being moved, redirection will temporarily break.
The targetAddress attribute will be restored by Directory Synchronization Agent (DSA) if the users are still in the scope of synchronization but only if there was a change in the source. If source account was not modified, then the DSA will not synchronize this account. Knowing this, a resynchronization for some accounts can be triggered by modifying any of the attributes in the source. This can also be done using a scripting approach. If many mailboxes were affected then full resynchronization is a good idea, it will re-populate the targetAddress attribute.
Please note that if the mailbox is still a part of the active collection, the Mail Target Agent (MTA) will move the mailbox to the store specified in the collection properties.
More details on this please see solution SOL15440 - Moving Target Mailboxes in the Middle of Mailbox Sync Job - https://support.quest.com/SUPPORT/index?page=solution&id=SOL15440