Topic Last Modified: 2007-03-15

The Microsoft Exchange Analyzer tool queries the ExchangeLink Microsoft Windows Management Instrumentation (WMI) class to check the status of the Simple Mail Transfer Protocol (SMTP) queues for an Exchange server.

SMTP is the native mail protocol for mail submission and mail transport for Exchange Server. This means that clients use SMTP to send messages and Exchange servers use SMTP to deliver messages and message data.

Properties of the ExchangeLink WMI class return information about message-handling links (queues) between mail servers. A link can contain zero or more ExchangeQueue objects. This number depends on the current message traffic along the link.

SMTP uses the SMTP queues to deliver mail internally and externally. During message categorization and delivery, the advanced queuing engine sends all mail through the SMTP queues of an SMTP virtual server. If there is a problem delivering the message at any point in the process, the message remains in the queue where the problem occurred.

Descriptions of SMTP queues

SMTP queue Description

[Local domain name] (Local Delivery)

Contains messages that are queued on the Exchange server for local delivery to an Exchange mailbox or public folder store.

Messages awaiting directory lookup

Contains messages to recipients that have not yet been resolved against Microsoft Active Directory directory service. Messages are also held here while distribution lists are expanded.

Messages waiting to be routed

Holds messages until their next-destination server is determined, and then moves them to their respective link queues.

Remote delivery

[Connector name|

 Server nameRemote domain]

Holds messages that are destined for remote delivery. The name of the queue matches the remote delivery destination, which may be a connector, a server, or a domain.

Final destination currently unreachable

The final destination server for these messages cannot be reached. For example, Exchange cannot determine a network path to the final destination.


Holds messages that have been acknowledged and accepted by the SMTP service. The processing of these messages has not begun.

DSN messages pending submission

Contains delivery status notifications, also known as non-delivery reports that are ready to be delivered by Exchange.

Note   The following operations are unavailable for this queue:

  • Delete All Messages (no NDR)

  • Delete All Messages (NDR)

Failed message retry queue

Contains messages that failed some type of queue submission, often before any other processing has taken place. By default, messages in this queue are reprocessed in 60 minutes.

Messages queued for deferred delivery

Contains messages that are queued for delivery at a later time, including messages that were sent by older versions of Outlook. (You can set this option on Outlook client computers.)

Previous versions of Outlook depend on the message transfer agent (MTA) for message delivery. Now, however, SMTP handles message delivery, not the MTA. Therefore, messages that are sent by older versions of Outlook treat deferred delivery differently.

These messages remain in this queue until their scheduled delivery time.

If the Exchange Analyzer cannot successfully complete the query to the ExchangeLink WMI class for a server, the Exchange Analyzer displays an error.

This error indicates that the WMI query was unable to retrieve the data requested.

The likely causes of this error are:

To correct this error, do the following:
  1. Make sure that the Exchange Server computer has been started and is connected to the network.

  2. Use the PING command to see if the Exchange Server computer is reachable.

  3. If there is a firewall, check to see if remote procedure call (RPC) ports are blocked.

  4. Examine the permissions for the account under which the Exchange Analyzer is running. The account under which the Exchange Analyzer is running must have local Administrator permissions on each Exchange server that it is scanning.

    Alternatively, you can grant specific WMI permission to the account under which the Exchange Analyzer is running:

    1. On the Exchange computer, open the Computer Management Microsoft Management Console (MMC) tree.

    2. Under Services and Applications, right-click WMI Control, and then click Properties.

    3. On the WMI Controls Property page, click the Security tab, and then expand Root.

    4. Select the CIMV2 folder, and click Security.

    5. On the Security for ROOT\CIMV2 page, add the account under which the Exchange Analyzer runs.

  5. Select the account that you added in Step 5 above. In Permissions for Selected_Account, under the Allow column, select both Remote Enable and Read Security, and then click OK.

For more information about troubleshooting network connectivity problems, see Microsoft Knowledge Base article 325487, "How to troubleshoot network connectivity problems" (

For more information about troubleshooting Exchange Best Practices Analyzer tool connectivity problems, see "Microsoft Exchange Server Best Practices Analyzer Tool Troubleshooting Connectivity Problems" (

For more information about port requirements, see Microsoft Knowledge Base article 832017, "Service overview and network port requirements for the Windows Server system" (