

If the Internet Service Provider (ISP) changes the domain name, they will also update it in the certificate.


So if you are one of the users who is encountering Outlook certificate error, then this could be due to various reasons. It is basically used to sign the emails in Outlook so that the receiver can be sure that the email has actually come from a legitimate person and has not been intercepted or altered by any other person. An Outlook security certificate is a digital certificate to secure the emails on Microsoft Outlook.
