Topic Last Modified: 2007-01-23

The Microsoft® Exchange Server Analyzer Tool uses the Exchange Server User Monitor (ExMon) tool to determine whether user MAPI operations are taking longer than should reasonably be expected on a healthy Exchange server.

As part of its analysis, the Exchange Server Analyzer reviews the ExMon data for user issued MAPI Synchronization operations that have taken longer than 30 seconds to complete.

MAPI Synchronization operations are performed to keep the Microsoft Office® Outlook® Offline Folder file (.ost) or local copy of the user's mailbox in sync with the user's mailbox data on the server.

MAPI Synchronization operations taking longer than 30 seconds may not always be a problem. By default, all e-mail messages that are stored on the Exchange Server and that are full copies of the Global Address List are downloaded to the user's computer when Cached Exchange Mode is first enabled in Outlook 2003.

During an initial synchronization with the Exchange Server, Outlook 2003 users may experience delayed responses.

If the user or users are experiencing frequent delays, or delays that adversely affect their messaging experience, subsequent to the initiation cached mode synchronization, these MAPI Synchronization operation delays should be investigated further to ensure they are not symptomatic of more serious latency issues such as resource bottlenecks.

Anytime there is a bottleneck for resources (generally a disk or CPU bottleneck), the latencies for the MAPI synchronization operations will increase. Identify server resource bottlenecks and either increase server resource capacity or move users to less-loaded server.

For More Information

For more information, see the following Exchange Server resources:

Performance and Scalability Guide for Exchange Server 2003 (http://go.microsoft.com/fwlink/?LinkId=47576)
Troubleshooting Microsoft Exchange Server 2003 Performance (http://go.microsoft.com/fwlink/?LinkId=47588)
"Exchange Server 2003 Performance: 10 Things to Think About" (http://go.microsoft.com/fwlink/?LinkId=56460)
Microsoft Knowledge Base article 905803, "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" (http://go.microsoft.com/fwlink/?linkid=3052&kbid=905803)