XCLN: Exchange Server Slows with Message Stuck in User Mailbox

The Exchange Server computer becomes very sluggish. If your are working at the console on the server, you notice the slowness. Clients sending or receiving messages also notice a slowdown.

Additional indicators of the problem covered in this article:

1. Store.exe is between 75% and 100% processor utilization.
2. The Performance Monitor counter Write Bytes RPC Clients/sec under the MSExchangeIS object stays at a high number (a rate of around 100,000 or above).
3. A network trace shows that the network segment is saturated. Most of the traffic will be RPC (remote procedure calls).
4. Go to the Private Information Store properties Logons tab. Add the Total Ops column. There will be users with 300 to 400 sustained Total Ops.

Some of the Exchange clients have a hung message on the server. When the user logs on to Exchange, the MAPI spooler on the client constantly tries to pull this message down. This problem does not prevent other messages from flowing to the client computer. When 20 to 30 users on the Exchange Server computer are in the same condition with the hung message, this will consume most of the Exchange Server computer's resources.

To work around this problem, do the following:

1. Go to the Private Information Store properties, Logons tab.
2. Add the Total Ops column and look at the result. Users having 300 to 400 sustained Total Ops are the users causing the problem.
3. After the users have been located, go to each user's computer. Open the e-mail client and look in the user's server mailbox. There should be a message there that cannot be pulled to the user's local PST. Delete that message. You must do this for all users with a high Total Ops count.

Microsoft has confirmed this to be a problem in the Exchange and Outlook clients listed above. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5. This problem has been corrected in the latest U.S. Service Pack for Microsoft Exchange Server version 5.5. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):