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Article ID: 270712 - Last Review: October 21, 2013 - Revision: 4.2

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This article was previously published under Q270712
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Messaging Application Programming Interface (MAPI), Post Office Protocol version 3 (POP3), Internet Message Access Protocol, Version 4rev1 (IMAP4), and Hypertext Transfer Protocol (HTTP) e-mail clients may experience very slow response from the Exchange Server information store, and gradually the information store may stop responding to the clients.

When a Microsoft Outlook user tries to log on, the user receives the following error message:
The Microsoft Exchange Server computer is not available. Either there are network issues or the Microsoft Exchange server is down for maintenance.
The Microsoft Windows Task Manager displays high CPU use for the Exchange Server information store and a large number of threads in the Store.exe process. The number of threads in the Store.exe process continues to increase, which causes the Store.exe process to stop responding.


This issue can occur if the information store process becomes stuck indefinitely in a loop when a folder cannot be deleted.


To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
191914  ( ) XGEN: How to Obtain the Latest Exchange Server 5.5 Service Pack
The following files are available for download from the Microsoft Download Center:
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Download Q248838engi.exe now (
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Download Q248838enga.exe now (
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591  ( ) How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.


Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.

  • Microsoft Exchange Server 5.5 Standard Edition
kbnosurvey kbarchive kbhotfixserver kbqfe kbbug kbexchange550presp4fix kbexchange550sp4fix kbfix kbgraphxlinkcritical kbqfe KB270712
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