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Thunderbird rejecting SSL certificate

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  • Last reply by Toad-Hall

admin450
admin450
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On both MAC and PC versions. I recently installed a new SSL certificate on one of our company servers. It works on most email applications without issue (Apple Mail, Outlook etc.) - but Thunderbird is complaining about the certificate. The certificate is coming from: sectigo.com

The error is: unknown identity The certificate is not trusted because it hasn't been verified as issued by a trusted authority using a secure signature.

If I confirm the default exception - it uses port: 443 - instead of ports 995 and 465.

A certificate exception has to be deployed by adding network.security.ports.banned.override to the configure editor. Adding a string of 995 and then 465 to make the exceptions. It doesn't always work....

I have used multiple online scanners and they all give green lights on the certificate. Any help appreciated... I have no idea where to go from here.

On both MAC and PC versions. I recently installed a new SSL certificate on one of our company servers. It works on most email applications without issue (Apple Mail, Outlook etc.) - but Thunderbird is complaining about the certificate. The certificate is coming from: sectigo.com The error is: unknown identity The certificate is not trusted because it hasn't been verified as issued by a trusted authority using a secure signature. If I confirm the default exception - it uses port: 443 - instead of ports 995 and 465. A certificate exception has to be deployed by adding network.security.ports.banned.override to the configure editor. Adding a string of 995 and then 465 to make the exceptions. It doesn't always work.... I have used multiple online scanners and they all give green lights on the certificate. Any help appreciated... I have no idea where to go from here.

Modified by admin450

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Toad-Hall
Toad-Hall
  • Top 10 Contributor
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Please post an image of error.

Do use use an installed Anti-virus eg: Norton ? Sometimes these errors can be caused by an Anti-Virus program.

But Thunderbird will also perform a check. I recently discovered someone had an account using a 'server name' which did not match the certificate and so was producing a similar error.

In 'Account Settings' > 'Server Settings' for the account which is producing the pop up error. What is in the 'server name' ?

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