Topic Last Modified: 2006-05-16

The Microsoft® Exchange Server Analyzer Tool queries the ExchangeLink Windows® Management Instrumentation (WMI) class to determine the value of the StateFrozen key for the Simple Mail Transfer Protocol (SMTP) Messages Pending Submission queue.

If the Exchange Server Analyzer finds that the value of the StateFrozen key for the Messages Pending Submission queue on an Exchange server is set to True, the Exchange Server Analyzer displays an error.

A frozen queue means the transport sessions for that queue are stopped. A frozen queue prevents outgoing messages, although new messages can be added. You can manually change the state of a connection by using the shortcut menu on each link queue. When you use the Force Connection command to change a queue state to Active, you immediately enable a connection that sends the messages from that queue.

The Messages Pending Submission queue holds messages that have been acknowledged and accepted by the SMTP service.

Messages that are in this queue have not been processed. If messages constantly accumulate, you may have a performance problem. Occasional peaks in CPU performance can cause messages to appear in this queue intermittently. Frequently, problems with event sinks, for example, custom SMTP processing code for antivirus screening and for disclaimers, cause messages to accumulate in this queue.

For more information about how to modify logging settings, see "How to Modify Logging Settings for MSExchangeTransport" in the "Troubleshooting Mail Flow and SMTP" section of the Exchange Server Transport and Routing Guide (

For more information about how to troubleshoot SMTP queues, see the following Exchange resources: