A feature is available to disable MAPI program access to a computer that is running Exchange Server 2003

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Article ID: 920185 - View products that this article applies to.
Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows registry
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This article describes a hotfix that adds a feature that you can use to disable MAPI application access to a computer that is running Microsoft Exchange Server 2003. After you apply this hotfix, you can disable MAPI client access according to the application executable name. You can use this feature to help prevent problematic or beta client MAPI applications from running against an Exchange Server computer.

Note This feature requires the connecting program to use the Microsoft Office Outlook 2003 MAPI client version.


Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


You must have Microsoft Exchange Server 2003 Service Pack 2 (SP2) installed to apply this hotfix.

Restart requirement

You do not have to restart your computer after you apply this hotfix. However, the Microsoft Exchange Information Store service stops and then restarts after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
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File nameFile versionFile sizeDateTimePlatform


Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

After you apply this hotfix, create the "Disable MAPI Client Processes" registry value to enable the hotfix. To create the "Disable MAPI Client Processes" registry value, follow these steps:
  1. Start Registry Editor.
  2. Locate and then click to select the following registry subkey:
  3. On the Edit menu, click Add Value, and then add the following registry value:
    • Value name: Disable MAPI Client Processes
    • Value type: REG_SZ
    • Value data: program1.exe; program2.exe
    Note Program1.exe and program2.exe are placeholders for the process names of the MAPI client programs that you want to disable.
  4. Exit Registry Editor.
  5. Restart the Microsoft Exchange Information Store service in the Services snap-in. Do this even if you are in a cluster environment.
Note In Exchange Server 2003, changes to this registry key are dynamically detected, as follows:
  • Every 15 minutes, the store queries the registry key.
  • If the registry key changes, these changes are immediately put into effect.
  • If any current open connections are established by using a newly blocked version, these connections are immediately disconnected.
  • All new connections are blocked if you are using a blocked version.
For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
817903 New naming schema for Exchange Server software update packages
895949 "Send As" permission behavior change in Exchange 2003


Article ID: 920185 - Last Review: October 9, 2011 - Revision: 4.0
  • Microsoft Exchange Server 2003 Standard Edition
  • Microsoft Exchange Server 2003 Enterprise Edition
kbautohotfix kbHotfixServer kbqfe kbfix kbbug KB920185

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