Validation of cryptographic signatures does not complete correctly in a transport event sink on Exchange 2000 Server or on Exchange Server 2003

In Microsoft Exchange Server 2000 or Microsoft Exchange Server 2003, when you use the Microsoft Collaboration Data Objects for Microsoft Exchange Library (CDOEX) to configure a transport event sink that handles incoming e-mail messages and validates cryptographic signatures, validation of the cryptographic signatures does not complete correctly.

This problem occurs because when messages are handled in the transport event sink by CDOEX, the S/MIME content of the message is altered and the S/MIME validation of the cryptographic signature cannot complete correctly.

Exchange Server 2003

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Exchange Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Exchange 2000 Server

Hotfix information

To resolve this problem, obtain the August 2004 Exchange 2000 Server Post-Service Pack 3 update rollup.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Prerequisites

Because of file dependencies, this update requires Exchange 2000 Server Service Pack 3 (SP3). For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

File information

The English version of this hotfix has the file attributes (or later) 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 tool in Control Panel.

Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
After you apply this hotfix, you must edit the registry and add the CDOHighFidelityInSinks value to the following registry subkey:
To add this registry value:

1. Click Start, click Run, type regedit, and then click OK.
2. Expand the following subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SMTPSVC\Parameters
3. Right-click Parameters, point to New, and then click DWORD Value.
4. Type CDOHighFidelityInSinks, and then press ENTER to name the value.
5. Right-click CDOHighFidelityInSinks, and then click Modify.
6. In the Value data box, type 00000001, and then click OK.
7. Close Registry Editor.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
This problem was first corrected in Microsoft Exchange Server 2003 Service Pack 2.