Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool has determined that you have specific types of client computers or client-side applications that may be increasing server load in your Exchange organization.

Many applications can increase the load on the server. If the load has increased, you should investigate what applications users are running and decide whether you want to restrict users from running certain applications. Some applications that access e-mail (third-party applications or Microsoft Office Outlook® plug-ins) may increase the load on the server. If the server experiences an increase in remote procedure call (RPC) latencies or an increase in load, it is recommended that you investigate the source.

You can use the Exchange Server User Monitor (ExMon) to identify users who are experiencing high latencies or are increasing the load on the server. To download ExMon, see the Microsoft Download Center (


To correct this warning

  • Use ExMon to identify which users causing an increase in server load. After the users are identified, contact the users and determine whether the following applications are causing the additional load:

    • Third-party client computer plug-ins

    • Desktop synchronization devices, such as Exchange ActiveSync® or Blackberry

    • Other MAPI applications, such as desktop search engines

    If these applications are not required for business purposes, or if the applications have a published hotfix, turn off the applications or update them to reduce the load to an appropriate level.

  • Configure the most operationally expensive client computers (especially those with long latencies on Restrict, SetColumns or FindRow operations) to use Cached Exchange Mode. Cached Exchange Mode isolates the server from most of the excess RPC traffic.

    Additionally, encourage users who have many items in their folders to archive older data to a .pst file. Or, if these users want to keep their data on the server, encourage them to move the older items into newly created folders.

    Lastly, it is recommended that you keep items in the Inbox, Calendar, Sent Items, Contacts and Deleted Items folders under 5,000.

Some applications can significantly increase server load without issuing a large number of MAPI operations. This is because some operations are more expensive than others. It may take only a small increase in the number of costly operations to noticeably impact server performance. In ExMon, these users are reported as having a relatively high CPU impact, without necessarily having issued a large number of MAPI operations.

For More Information

  • For more information about Exchange Server performance, see the Exchange Server 2003 Performance and Scalability Guide (

  • For more information about troubleshooting Exchange Server performance issues, see Troubleshooting Microsoft Exchange Server 2003 Performance (

  • For more information about troubleshooting Outlook client performance issues, see "Outlook users experience poor performance when they work with a folder that contains many items on a server that is running Exchange Server 2003 or Exchange 2000 Server" (

  • For more information about desktop search software, see the Microsoft Knowledge Base article 905184, "Exchange 2000 Server and Exchange Server 2003 performance may be affected when desktop search engine software is running on Outlook or other MAPI client computers" (