Article ID: 979517 - View products that this article applies to.
In a mixed Microsoft Exchange Server 2007 and Microsoft Exchange Server 2010 environment, a message that is sent to a Dynamic Distribution Group fails. Additionally, you receive the following non-delivery report (NDR) message:
#550-5.7.1 Delivery not authorized, message refused. 550-5.7.1 Message targeted to organization's federated delivery mailbox. 550 5.7.1 Please contact your system administrator for more information. ##
Note The NDR includes "DiscoverySearchMailbox" and "FederatedEmail" system mailboxes. This is unexpected. If you view the members that appears in the Dynamic Distribution Group by using Exchange Management Console, the system mailboxes are not listed. However, if you view the members that appears in the Dynamic Distribution Group by using Exchange Management Shell, the system mailbox are listed. If the Dynamic Distribution Group is expanded on an Exchange Server 2007 server, the NDR is generated for all the Exchange Server 2010 recipients. If the Dynamic Distribution Group is expanded on an Exchange Server 2010 server, the NDR is only generated for the DiscoverySearchMailbox system mailbox.
This problem occurs because Exchange Server 2010 does not exclude system mailboxes from a Dynamic Distribution Group.
To resolve this problem, install the following update rollup:
(http://support.microsoft.com/kb/982639/ )Description of Update Rollup 4 for Exchange Server 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to view members of a Dynamic Distribution Group, visit the following Microsoft website:
General information about how to view members of a Dynamic Distribution Group