Mail sent to migrated users generates a large number of NDRs (26347)

After a user mailbox has been migrated to the target Exchange organization, people sending to that user receive a large number of non-delivered (NDR) reports like the following:

From: System Administrator
Sent: Monday, February 06, 2006 3:12 PM
To: user.name@private.domain
Subject: Undeliverable: test

Your message did not reach some or all of the intended recipients.
Subject: test
Sent: 2/6/2006 1:58 PM

The following recipient(s) could not be reached:
user.name@private.domain on 2/6/2006 3:12 PM
No route was found for the recipient server. Please contact your system administrator. The MTS-ID of the original message is: c=US;a=;p=domain;l=servername <servername.private.domain #5.4.4>

where user.name@private.domain is the redirection address stamped on the user in both the source and destination organizations to allow redirecting mail flow between the source and target mail environments while mailboxes are being migrated.

When migrating a user mailbox to the target,Directory Synchronization Agent of QMM for AD copies most of the AD properties from the source account to the newly-created target account. Attributes AltRecipient and deliverAndRedirect correspond to the following settings in ADUC (Active Directory Users and Computers): Exchange General | Delivery Options | Forward to and Deliver Messages to Both Forwarding Address and Mailbox checkbox.

If AltRecipient on the source refers to the user that was not migrated to the target its value on the target is blank while deliverAndRedirectis still copied as TRUE. Therefore, the messages sent to the user in question are generated as messages with the blank destination address, which causes unexpected results in Exchange. The Deliver Messages to Both Forwarding Address and Mailbox checkbox cannot be manually edited (modified) using AD Users and Computers snap-in, as it is grayed out in the

This issue can be resolved by installing the following hotfix: MigrationManager_8.8_Update_20121123

The hotfix can be found and downloaded by visiting the KB article 77417

TO RESOLVE THE ISSUE MANUALLY USE THE FOLLOWING WORKAROUND:

1. Skip deliverAndRedirect attribute from directory synchronization.
2. On the target user set the deliverAndRedirect attribute to FALSE value using ADSIEdit snap-in. This will Disable Deliver Messages to Both Forwarding Address and Mailbox check box in ADUC.
3. Clear the check box using the AD Users and Computers snap-in.

STATUS: Enhancement request ST38635 has been submitted to Development for consideration in a future release. This enhancement was to modify the switching behavior and it was implemented in the hotfix 20121123.

For more information please refer Microsoft article under http://support.microsoft.com/kb/924234