This article was previously published under Q276597
Important This article contains information about how to modify the registry. Make sure that you 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:
When you send a secure message in Microsoft Outlook 2013, Microsoft Outlook 2010, Microsoft Office Outlook 2007, Microsoft Office Outlook 2003, Microsoft Outlook 2002, or in Microsoft Outlook 2000, you may need to use a certificate that does not match your e-mail address. This article describes how to turn off e-mail matching for certificates.
You can turn off e-mail address matching for certificates by editing your registry. To do this, follow these steps, as appropriate for the version of Outlook that you are running.
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 the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
Click Start, click Run, type regedit in the Open box, and then click OK.
When you send an encrypted email message to a recipient, Outlook uses the recipient's certificate to secure the message. If the email address of the contact or recipient is different from the email address that is specified in the recipient's certificate, you receive the following warning:
Microsoft Outlook had problems encrypting this message because the following recipients had missing or invalid certificates, or conflicting or unsupported encryption capabilities:
Continue will encrypt and send the message but the listed recipients may not be able to read it.
To prevent Outlook from displaying this warning message, apply the registry change described in the Resolution section of this article.