XFOR: MSMI Stops Processing Mail

The information in this article applies to:

  - Microsoft Exchange Server, versions 4.0 and 5.0

SYMPTOMS

The Microsoft Mail Connector interchange (MSMI) stops processing mail. This can be evidenced by the following symptoms:

   A backlog builds in the message transfer agent's (MTA's) MSMI queue.

   P1 files build up in Exchsrvr\Connect\Msmcon\Maildata\P1.

   In Performance Monitor, observe the thread object"% processor time"
   counter for all MT.EXE threads. All threads above number 3 except one
   (typically number 6 on a singleCPU computer) will show no processor
   utilization (threads 0 through 3 typically show no processor
   utilization except during startup, shutdown, or thread and data
   refresh).

   The following MSMI event messages are repeatedly logged in pairs:

      2380 - A memory access violation has occurred that prevents further
      processing of a message.  The access violation that occurred is an
      attempt to read from <same memory address>.  Please refer to the
      immediately following event(s) logged by MS Mail Connector
      interchange for more information on the message that could not be
      processed.(Exception address: %2.)

      2450 - MS Mail Connector Interchange has failed processing message
      from Exchange. The message is left in the delivery queue. Use the MS
      Exchange Administrator to view the details for this message or remove
      it from the queue. This message is from <same originator address>.
      This error message will be logged again the next time MS Connector is
      restarted if the message is not removed from the queue

CAUSE

The MSMI's outbound processing thread(s) have raised a handled exception while "owning" a thread synchronization object (mutex) that other threads are waiting for. While the exception is handled, the mutex is not properly released, resulting in "blocked" execution of the other threads.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. A supported fix to this problem is in development, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information on the availability of this fix.

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.0. This problem was corrected in the latest Microsoft Exchange 5.0 Server 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

The fix adds a try/finally block around the mutex acquisition and release code. This ensures the mutex is always released, even if an exception occurs.

Keywords          : kbbug4.00 kbbug5.00 kbfix5.00.sp1 XFOR kbusage buglist
Version           : 4.0 5.0
Platform          : WINDOWS
Issue type        : kbbug