PGP Alert - Invalid Authentication Certificate

Article:TECH149615  |  Created: 2009-11-02  |  Updated: 2012-08-20  |  Article URL
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Technical Solution


When starting your email client, you receive a PGP Alert that an authentication certificate is not valid.



This PGP Alert can occur when the certificate for your mail server includes an invalid certificate. These PGP Alerts are displayed when there is an issue with a certificate distributed by your email server. You may select to Always Allow for This Site, Allow, or Deny the certificate.


Note: The certificate alert does not affect the encryption of email messages with PGP Desktop.

An invalid certificate can be displayed for the following reasons:


  • Certificate mismatch - This appears when the name of the certificate does not match the name of the mail server domain being connected to by the email client. This can occur when using your email client with a gmail account.

  • Unknown Certificate Authority - This occurs when the mail server has a certificate which has been issued by an unknown certificate authority. This can occur when the mail server is using self signed certificate and not a certificate from a Certificate Authority.  Check the certificate path of the PGP  Universal Server website to confirm that it is secured (you should see something similar to a lock icon confirming it is secured).  If a trusted Certificate Authority certificate does not exist in the local certificate store you will receive this alert.  By checking a secured certificate path if a certificate does not exist in the local certificate store Microsoft will dynamically add the certificate to the local certificate store.  Newer certificate authority certificates may require Operating System updates. 


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