XCON: Messages Back Up in the Queue When You Forward Mail with Unresolved Recipients to the Host (289808)

The information in this article applies to:

Microsoft Exchange 2000 Server
Microsoft Exchange Server 5.5

This article was previously published under Q289808

SYMPTOMS

When you configure a Simple Mail Transfer Protocol (SMTP) virtual server to forward all mail that contains unresolved recipients to the host, and then specify a third-party SMTP server or a Exchange Server 5.5 computer, the messages may back up in the host queue, and may not be delivered.

CAUSE

This issue can occur if the third-party SMTP server or Exchange Server 5.5 computer does not support 8-bit MIME formats.

RESOLUTION

To resolve this issue, disable 8-bit MIME for the Microsoft Windows SMTP service. For additional information about how to disable 8-bit MIME, click the article number below to view the article in the Microsoft Knowledge Base:

262168 How to Disable 8-bit MIME in Windows 2000 SMTP Service

MORE INFORMATION

If you track one of the messages that is in the queue, the message gets submitted to the categorizer, but it goes no further. Also, if you increase the diagnostic logging level for MSExchangeTransport, the following event message is logged:

Event ID 4000
Message delivery to the remote domain [IP address of host] failed.

If you restart the server with the SMTP service, the messages get delivered.

Modification Type:	Minor	Last Reviewed:	4/25/2005
Keywords:	kberrmsg kbprb KB289808