Replication Receive Queue queue length beyond threshold

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-02-13

The Microsoft® Exchange Server Analyzer Tool includes a performance data collection engine that is used to query performance counter objects on computers that are running Exchange 2000 Server or Exchange Server 2003. The performance data collection engine collects data from the Replication Receive Queue Size performance counter of the MSExchangeIS Public performance object to analyze performance data.

If the Exchange Server Analyzer determines that the Replication Receive Queue Size counter has exceeded the peak value of 1000 during the sample time slice, the Exchange Server Analyzer displays an error.

Public folder replication messages are received by SMTP, categorized and handed to the local SMTP queue. The messages are then submitted to the Public Folder store. When they have been submitted to the Public Folder store the messages are put in the Replication Receive Queue. The messages in the Replication Receive Queue are then processed and the changes are performed on the appropriate public folder. The Replication Receive Queue Size performance counter indicates the number of public folder replication messages waiting to be processed.

The larger the replication queue becomes, the more out of synchronization the content in the folders becomes. When replication queues grow, there is an increased load on resources as the messages in the replication queue are processed. Also, growing replication queues indicate that public folder content on the server is outdated.

No action is required in the two instances where growth in the Replication Receive Queue is expected and can be planned for:

  • On a newly introduced public folder server, growth in the Replication Receive Queue can be caused by the expected initial backfill replication.

  • If site consolidation or other major changes in the Exchange topology are occurring, it is expected that there will be lots of replication as the content is moved.

For existing, steady state servers where public folder replicas are not being changed in bulk, this error may indicate:

  • Server resource performance bottlenecks such as disk, CPU, network, or memory. If there is a resource bottleneck on the server, the Store.exe process will not be able process the replication messages fast enough and a queue will grow.

  • The public folder replication interval is too small for the replication to complete before the next replication cycle starts.

To resolve this error, take the following steps:

  • Increase the replication interval time and monitor the MSExchangeIS Public\Replication Receive Queue Size until it shows that replication is completed before the next replication cycle starts.

  • Use the resources in the following links to determine whether a performance bottleneck is causing the queue growth and to address the bottleneck.

  • Consider reducing the total number of replicas in the Exchange organization to reduce the amount of replication traffic required.

For More Information

  • For more information about troubleshooting Exchange Server performance issues, see "Handling Special Exchange Roles and Performance" in Troubleshooting Microsoft Exchange Server Performance (

  • For more information about Exchange Server public folder replication, see "Controlling Exchange Server 2003 Public Folder Replication" in Working with the Exchange Server 2003 Store (

  • For more information about Exchange public folder best practices, see Exchange Public Folder Best Practices: Implementing Replication (

  • For more information about improvements in public folder management introduced with Exchange Server 2003 Service Pack 2, see Microsoft Exchange Server 2003 Service Pack 2 Release Notes (