XCON: IMC Stops Processing Mail on Alpha Platform

• Microsoft Exchange Server, version 4.0

SYMPTOMS

The Internet Mail Connector (IMC) stops processing outbound messages. If the IMC is not running, any attempts to start the IMC fail with an event 1067. No other events are logged. DEC Alpha platforms seem to be susceptible to this problem. Use of Mdbvu32 will show messages sitting in the MTS-OUT folder.

CAUSE

The attachment to the message has been corrupted at some point. The PR_ATTACHMENT_ENCODING is obtained from the Winmail.dat because the message was sent in TNEF but the actual attachment consists of only the data fork because the resource fork has been stripped. Imail processes the attachment as MAC_BINARY and reads the first 128 bytes of the header and incorrectly determines the filename length. The erroneous filename length leads to corruption of memory and an eventual crash of the IMC.

WORKAROUND

To work around this problem, do one of the following:

• Use the resource kit utility Imcsave to remove the messages and save the contents of the MTS-OUT folder.

• Use Mdbvu32 to copy messages out of the MTS-OUT folder. Remove the first message and try to start the IMC.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange version 4.00. This problem was corrected in the latest Microsoft Exchange 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

DEC Alpha platforms are manufactured by Digital Equipment Corporation, a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.