How to turn off e-mail matching for certificates in Outlook

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, see Description of the Microsoft Windows registry.

Summary

When you send a secure message in Outlook, you may need to use a certificate that doesn't match your e-mail address. This article describes how to turn off e-mail matching for certificates.

Resolution

You can turn off e-mail address matching for certificates by editing your registry. To do so, 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.

Outlook for Microsoft 365, Outlook 2019, and Outlook 2016

  1. Select Start > Run, type regedit in the Open box, and then select OK.
  2. Locate the registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Security.
  3. If a Security registry key doesn't exist, follow these steps to create a new key:
    1. Select the registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook.
    2. On the Edit menu, point to New, and then select Key.
    3. Type Security, and then press Enter.
  4. Right-click the Security key, select New, and then select DWORD Value.
  5. Type SupressNameChecks, and then press Enter.
  6. On the Edit menu, select Modify.
  7. Type 1, and then select OK.
  8. On the Registry menu, select Exit.

Outlook 2013

  1. Select Start > Run, type regedit in the Open box, and then select OK.
  2. Locate the registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Outlook\Security.
  3. If a Security registry key doesn't exist, follow these steps to create a new key:
    1. Select the registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Outlook.
    2. On the Edit menu, point to New, and then select Key.
    3. Type Security, and then press Enter.
  4. Right-click the Security key, select New, and then select DWORD Value.
  5. Type SupressNameChecks, and then press Enter.
  6. On the Edit menu, select Modify.
  7. Type 1, and then select OK.
  8. On the Registry menu, select Exit.

Outlook 2010

  1. Select Start, select Run, type regedit in the Open box, and then select OK.
  2. Locate the following registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\14.0\Outlook\Security.
  3. If a Security registry key doesn't exist, follow these steps to create a new key:
    1. Select the registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\14.0\Outlook.
    2. On the Edit menu, point to New, and then select Key.
    3. Type Security, and then press ENTER.
  4. Right-click the Security key, select New, and then select DWORD Value.
  5. Type SupressNameChecks, and then press Enter.
  6. On the Edit menu, select Modify.
  7. Type 1, and then select OK.
  8. On the Registry menu, select Exit.

More information

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:

Encryption Problems

Microsoft Outlook had problems encrypting this message because the following recipients had missing or invalid certificates, or conflicting or unsupported encryption capabilities:

recipient name

Continue will encrypt and send the message but the listed recipients may not be able to read it.

Send UnencryptedContinueCancel

To prevent Outlook from displaying this warning message, apply the registry change described in the Resolution section and restart Outlook.