Topic Last Modified: 2006-05-17

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 awaiting directory lookup queue.

If the Exchange Server Analyzer finds that the value of the StateFrozen key for the Messages awaiting directory lookup 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 awaiting directory lookup queue contains messages to recipients that have not yet been resolved against the Active Directory® directory service. Messages are also held in the queue while distribution lists are expanded.

Generally, messages accumulate in this queue because the advanced queuing engine is unable to categorize the message. The advanced queuing engine may not be able to access the global catalog servers and access recipient information, or the global catalog servers are unreachable or performing slowly. In addition, messages can accumulate for the following reasons:

To resolve this error, increase diagnostic logging for the MSExchangeDSAccess service and for the MSExchangeTransport service to collect information about Categorizer components.

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