Users sometimes cannot see attachments that have the .p7m extension in Outlook

Users in a Microsoft Exchange Server 2003 organization sometimes cannot see attachments that have the .p7m extension in the following versions of Microsoft Outlook:

• Microsoft Office Outlook 2003
• Microsoft Outlook 2002
• Microsoft Outlook 2000

However, users can see attachments that have the .p7m extension if one of the following conditions is true:

• Common attachments, such as .xls files or .doc files, are attached in addition to the .p7m attachment.
• The e-mail message is converted from MIME to MAPI.
• A user edits and saves the message.
• The envelope or the parent message is encrypted or signed.

Note The .p7m extension is used for encrypted files that are sent as attachments.

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.

Hotfix installation information

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 the hotfix, you must configure the following registry entry under the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem registry subkey:

Prerequisites

You must install Microsoft Exchange Server 2003 Service Pack 2 (SP2) before you apply the hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You do not have to restart the computer after you apply the hotfix. However, the Microsoft Exchange Information Store service and all dependent services will be restarted.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about the terminology that Microsoft uses for software that is corrected after it is released, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the naming schema for Exchange Server software updates, click the following article number to view the article in the Microsoft Knowledge Base: