XFOR: Message Containing Null Recipient Address Is Not Delivered

If you send an e-mail message that contains a null recipient address through an Exchange 2000 Server computer, and the Exchange 2000 Server computer routes the message through the Internet Mail Service on an Exchange Server 5.5 computer, the message may not be delivered. When this occurs, you do not receive a non-delivery report.

To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.