Situation: When the user opens Outlook, he gets this error: “The name on the security certificate is invalid or does not match the name of the site”
Troubleshooting: In most cases, this is Autodiscover Domain Name System (DNS) records issue. Use https://testconnectivity.microsoft.com/ to troubleshoot Autodiscover problem or This Microsoft article may help:
“The name on the security certificate is invalid or does not match the …https://support.microsoft.com/…/the-name-on-the-security-certificate-is- invalid-or-does-not-match-the
Or try to clear the cache.
