Topic Last Modified: 2010-02-16

The Microsoft Exchange Server 2010 Management Pack for System Center Operations Manager includes a performance data collection engine that is used to query performance counter objects on computers running Exchange 2010. For this Operations Manager rule, data is collected by using the performance counter specified in the Details table.

To review the value of the performance counter that generated this alert, in Operations Manager, double-click this alert, and then click the General tab. Review the description of the alert that includes the variables specific to your environment.


Product Name


Product Version

14.0 (Exchange 2010)

Object Name

MSExchangeTransport Queues

Counter Name

Retry Mailbox Delivery Queue Length

Instance Name


Sample Interval


Server Role

Ex14. Hub Transport

Warning Threshold


Rule Path

Microsoft Exchange Server/Exchange 2010/Hub Transport/Transport Queues

Rule Name

Retry Mailbox Delivery Queue Length - sustained for 5 minutes - Yellow(>200) - Hub Transport.


The Retry Mailbox Delivery 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.

This alert indicates that the retry mailbox delivery queue length has been greater than 200 for five minutes. This alert may be caused by any of the following:

  • A computer on your network may be infected with a virus which is sending messages through your Exchange servers.

  • Your DNS server may have some issue resolving FQDNs of mailbox servers to IP addresses.

  • There may be a network connectivity issue that is preventing your server from correctly connecting to the destination mailbox servers. Some possible issues that could affect your connection are:

    • Router or routing issues between your server and the destination.

    • Other network issues between your server and the destination.

User Action

To resolve this alert, do the following:

  • Verify that your server is able to connect to DNS to resolve IP addresses.

  • Check the network connectivity between your Hub Transport server and the mailbox servers. Use the Ping or PathPing command-line tools to test basic connectivity. Use Ping to isolate network hardware problems and incompatible configurations. Use PathPing to detect packet loss over multiple-hop trips. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.

  • Resolve your issue by using self-support options, assisted support options, and other resources. You can access these resources from the Exchange Server Solutions Center. From this page, click Self-Support Options in the navigation pane to use self-help options. Self-help options include searching the Microsoft Knowledge Base, posting a question at the Exchange Server forums, and others. Alternatively, in the navigation pane, you can click Assisted Support Options to contact a Microsoft support professional. Because your organization may have a specific procedure for directly contacting Microsoft Technical Support, be sure to review your organization's guidelines first.

For More Information

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.