Using X.400 (MTA) Queues to Troubleshoot Message Flow

 

Exchange Server 2003 uses the X.400 queues to submit mail to and receive mail from Exchange 5.5 servers and to send mail through connectors to other mail servers. If you experience mail flow problems when you are sending mail to an Exchange 5.5 or earlier server, or to another mail system to which you are connecting using X.400, check the X.400 queues on the Exchange server. If you experience mail flow problems when sending mail to servers that are running Exchange 5.5 or earlier, it is a good idea to also check the MTA queues on those servers. For detailed instructions, see How to Configure Diagnostic Logging for the X.400 Service (MSExchangeMTA).

The following table the X.400 queues, their descriptions, and troubleshooting information for message accumulation in each queue.

X.400 queues

Queue name Description Causes of message accumulation

PendingRerouteQ

Contains messages that are waiting to be rerouted after a temporary link outage.

Messages can accumulate in this queue if a route to a connector, to a different mail system, or to an Exchange 5.5 server is unavailable.

Next hop MTA

Contains messages destined to one of the following:

  • Another gateway, such as a connector for Lotus Notes or Novell GroupWise.

  • An X.400 link to an Exchange 5.5 site or a destination outside the organization.

  • An Exchange MTA over the LAN—for example, destined to an Exchange 5.5 server in a mixed-mode environment.

Messages can accumulate in this queue when Exchange 2003 experiences problems sending to another mail system, to an Exchange 5.5 server, or through an X.400 link.

Increase diagnostic logging for the X.400 service as described in "How to Configure Diagnostic Logging for the X.400 Service (MSExchangeMTA)."