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sec_error_unknown_issuer on my TB, but not on my workmates'

  • 1 reply
  • 1 has this problem
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  • Last reply by Matt

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Hello,

My Thunderbird doesn't display images in html emails coming from my https website. Error console says:

www.mysite.com:443 uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown (Error code : sec_error_unknown_issuer)

This si *my* Thunderbird, on Ubuntu. My workmates also use Thunderbird (but on Windows) and images display correctly...

Can anyone tell me what the problem is (or could be)? I'm not interested in fixing this only in my Thunderbird by installing something which is absent from a default installation. I'm curious as to why this happens, I'd like to know if there's something wrong with the certificate on my website (a Comodo PositiveSSL wildcard certificate from https://www.ssls.com/ssl-certificates/comodo-positivessl-wildcard)

Thanks in advance

Hello, My Thunderbird doesn't display images in html emails coming from my https website. Error console says: www.mysite.com:443 uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown (Error code : sec_error_unknown_issuer) This si *my* Thunderbird, on Ubuntu. My workmates also use Thunderbird (but on Windows) and images display correctly... Can anyone tell me what the problem is (or could be)? I'm not interested in fixing this only in my Thunderbird by installing something which is absent from a default installation. I'm curious as to why this happens, I'd like to know if there's something wrong with the certificate on my website (a Comodo PositiveSSL wildcard certificate from https://www.ssls.com/ssl-certificates/comodo-positivessl-wildcard) Thanks in advance

All Replies (1)

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when you get the error you should also get an option to view the SSL certificate. My guess is that somewhere in the chain of trust there is a missing link. Have you deleted any certifying authorities? in the certificate manager? Is the certificate presented the one you think it is?

One of the things we are seeing is anti virus products issuing their own top level certificate authority certificates so they can man in the middle hack SSL connections. Avast springs to mind.

These certificate just "appears in the connection when the anti virus tried to do the man in the middle. While your using a Linux distribution, a corporate environment says you probably have some sort of mail scanner as a requirement.