• Article

Unreachable Queue Length - sustained for 5 minutes - Red(>250) - Edge Transport

 

Topic Last Modified: 2007-11-16

The Microsoft Exchange Server 2007 Management Pack for Operations Manager includes a performance data collection engine that is used to query performance counter objects on computers that are running Exchange Server 2007. For this Operations Manager rule, data is collected using the performance counter specified in the Details table.

To review the value of the performance counter that generated this alert, do one of the following:

  • If you are using Microsoft Operations Manager 2005, from the Operator Console, select this alert, and then click the Properties tab. Review the description of the alert that includes the variables specific to your environment.

  • If you are using System Center Operations Manager 2007, double-click this alert, and then click the General tab. Review the description of the alert that includes the variables specific to your environment.

Details

Product Name

Exchange

Product Version

8.0 (Exchange Server 2007)

Event Source

MSExchangeTransport Queues

Counter Name

Unreachable Queue Length

Instance Name

_Total

Sample Interval (in seconds)

60

Server Role

Ex. Edge Transport

Critical Error Threshold

>250

MOM Rule Path

Microsoft Exchange Server/Exchange 2007/Edge Transport/Transport

MOM Rule Name

Unreachable Queue Length - sustained for 5 minutes - Red(>250) - Edge Transport.

Explanation

The Unreachable Queue Length performance counter measures the number of messages currently in the retry mailbox delivery queue. Messages in this queue are in a retry state because an issue prevented their delivery. If the issue is transient, a subsequent attempt to send the message may be successful.

Messages that cannot be successfully delivered are subject to various retry, resubmit, and expiration deadlines based on the message's source and destination. Retry is a renewed connection attempt with the destination domain, smart host, or Mailbox server. Resubmit is the act of sending messages back to the submission queue for the categorizer to reprocess. The message is said to "time-out", or expire, after all delivery efforts have failed during a specified period of time. After a message expires, the sender is notified of the delivery failure. Then the message is deleted from the queue.

In all three cases of retry, resubmit, or expire, you can manually intervene before the automatic actions are performed on the messages

This alert indicates that the unreachable queue length has been greater than 250 for five minutes.

The categorizer sends messages to the unreachable queue when there is no known route to their destinations. Typically, an unreachable destination is caused by a configuration error that affects the delivery path. For example, the messages will be sent to the unreachable queue if the following conditions are true:

  • There are messages in the "Contoso.com" remote delivery queue.

  • You delete the Send connector that is used to reach the Contoso.com domain.

By default, the messages in the unreachable queue have the status of Ready. Messages in the unreachable queue are never automatically resubmitted. Messages remain in the unreachable queue until they are manually resubmitted by an administrator, removed by an administrator, or the value specified in the MessageExpirationTimeOut parameter passes.

For more information about the unreachable queue, see Managing Queues.

User Action

To resolve this alert, resubmit the messages in the unreachable message queue. You can do this by using Exchange Queue Viewer or by running the Resume-Message cmdlet in the Exchange Management Shell.

For information about Queue Viewer, see Using Queue Viewer to Manage Queues.

For information about the Resume-Message cmdlet, see Resume-Message.

For More Information

To search the Microsoft Knowledge Base articles based on criteria that generated this alert, visit the Microsoft Help and Support Web site.

If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.