The Isinteg.exe tool is running in a dismounted mailbox store on a server that is running Microsoft Exchange Server 2007. Additionally, the Microsoft Exchange Transport service is running on the Exchange 2007 server. When you send an e-mail message to a mailbox that is included in the dismounted mailbox store, you receive the following non-delivery report (NDR) message:
When the mailbox store of the destination mailbox is dismounted to run the Isinteg.exe tool, the message is queued in the recipient's local delivery queue. However, Exchange 2007 marks the delivery as a permanent error. This causes the 5.2.0 NDR message.
To resolve this problem, install Update Rollup 3 for Exchange Server 2007. For more information about Update Rollup 3 for Exchange Server 2007, see the following Exchange Help topic:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 932515 - Last Review: Aug 25, 2009 - Revision: 1