Assume that you have a mailbox on an Active Directory site in a Microsoft Exchange Server 2010 environment. When you use a BlackBerry device to connect to a different Active Directory site, the Exchange server tries to proxy the connection. However, the server should redirect the request.
This issue occurs because the BlackBerry device is not in the redirect device list.
To resolve this issue, install the following update rollup:
2891587 Description of Update Rollup 3 for Exchange Server 2010 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the 451 redirect error, go to the following Microsoft website:
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.