Assume that you try to send a message that has an attachment to a distribution list in a Microsoft Exchange Server 2007 environment. However, the message is not delivered, and you receive a non-delivery report (NDR) that contains the following information:
This issue occurs because of a race condition when Exchange server submits messages. The race condition occurs when different threads process a message at the same time. Therefore, the categorizer treats the message as corrupted and blocks the message submission.
To resolve this issue, install the following update rollup:
2655203 Description of Update Rollup 7 for Exchange Server 2007 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 how to manage content conversion tracing, visit the following Microsoft website: