How to turn off e mail matching for certificates in outlook

To turn off email matching for certificates in Outlook, you can follow these steps:

Method 1: Disable Email Matching for Certificates through Outlook Options

  1. Open Outlook and go to the "File" menu.
  2. Click on "Options" (or "Office Account" in Outlook 2019 and later).
  3. In the Outlook Options window, click on "Trust Center" in the left-hand menu.
  4. Click on "Trust Center Settings" at the bottom of the window.
  5. In the Trust Center Settings window, click on the "Certificates" tab.
  6. Uncheck the box next to "Email matching for certificates" under the "Certificate validation" section.
  7. Click "OK" to close the Trust Center Settings window.
  8. Click "OK" again to close the Outlook Options window.

Method 2: Disable Email Matching for Certificates through Registry Editor (for advanced users)

  1. Open the Registry Editor (Regedit.exe) on your computer.
  2. Navigate to the following registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Trust Center
  3. Create a new DWORD value named DisableEmailMatchingForCertificates and set its value to 1.
  4. Close the Registry Editor.

Method 3: Disable Email Matching for Certificates through Group Policy (for enterprise environments)

  1. Open the Group Policy Editor (GPEdit.msc) on your computer.
  2. Navigate to the following policy setting: Computer Configuration\Administrative Templates\Microsoft Office 2016\Outlook\Trust Center
  3. Enable the policy setting "Disable email matching for certificates" and set its value to Enabled.
  4. Close the Group Policy Editor.

After disabling email matching for certificates, Outlook will no longer check the email address in a certificate against the sender's email address when validating the certificate.