In the recently released Exchange 2007 Service Pack 3, there’s a version mismatch between the Outlook Web Access (OWA) S/MIME Control, an Active X control used to provide S/MIME support in OWA. After you install SP3, users who have the control installed will get prompted to install the latest version of the control.
The way this works – the code compares the “Version” property of the client S/MIME control (MIMECTL.DLL) on the user’s computer with the ProductVersion property of the MSI file (OWASMIME.MSI) on the Client Access Server.
During the released SP3 build, the version of the MSI file was incremented to 126.96.36.199. However, due to an error, the DLL file in the MSI retained its old version number (188.8.131.52). As a result, when Outlook Web Access users using Internet Explorer use S/MIME functionality, they get the same prompt to upgrade the S/MIME control even after they’ve upgraded.
Here are two ways to resolve this issue.
If you have the Orca.exe utility, you can change the version number of the \Microsoft\Exchange Server\ClientAccess\Owa\smime\owasmime.msi file from 184.108.40.206 to 220.127.116.11.
Download and run the PatchMSIProductVersion.vbs script which changes the version number. Note, the download is named PatchMSIProductVersion.vbs_txt. Remove the _txt from the file extension before running it.
After you use either of the above methods, restart IIS. (Use the IISReset command.)
We apologize for any inconvenience this may have caused users.
NOTE: If your users don’t use the S/MIME control, no action is required. Some discussions in community forums include another possible workaround which suppresses the upgrade prompt by using the ForceSMIMEClientUpgrade registry key (see How to Manage S/MIME for Outlook Web Access in Exchange 2007 docs for details). Although this may work under the situation, we do not recommend using this method for this version mismatch issue on an ongoing basis.