XADM: High CPU in Store.exe with Incorrectly Formatted Attachment

When you monitor the activity of Store.exe using various tools, including Performance Monitor, Store.exe runs near or at 100 percent CPU usage.

The messaging client is improperly formatting a message containing a MIME attachment. This can occur for messages containing attachments that contain a left parenthesis "(" within the file name but without the right or closing parenthesis ")". This is interpreted as a comment rather then the file name, and the store continuously searches for the closing parenthesis.

For example: It is possible to check the files in the IMCDATA\IN or IMCDATA\OUT subdirectories for the presence of messages that contain attachments with a ( in the file name. These files are text files. There is no need to check the archive directories underneath IN or OUT.

Exchange Server 5.0

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft Exchange Server version 5.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

Component: Information Store

File name	Version
Mdbmsg.dll	5.0.1461.91
Store.exe	5.0.1461.91

Exchange Server 5.5

To resolve this problem, obtain the latest service pack for Microsoft Exchange Server version 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: The English version of this fix should have the following file attributes or later:

Component: Information Store

File name	Version
Store.exe	5.5.2144.0

Microsoft has confirmed that this is a problem in Microsoft Exchange Server versions 5.0 and 5.5. This problem was first corrected in Microsoft Exchange Server version 5.5 Service Pack 1.