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Why might a certificate be rejected by THunderbird?

redhead3638
redhead3638
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I get the following message when I check the sender's signature:

This certificate can't be verified and will not be imported. The certificate issuer might be unknown or untrusted, the certificate might have expired or been revoked, or the certificate might not have been approved.

I get the following message when I check the sender's signature: This certificate can't be verified and will not be imported. The certificate issuer might be unknown or untrusted, the certificate might have expired or been revoked, or the certificate might not have been approved.

All Replies (2)

Gnospen
Gnospen
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Here is how to install a senders certificat SMIME : http://kb.mozillazine.org/Installing_an_SMIME_certificate

redhead3638
redhead3638 Question owner
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Thanks for the article - it explained my problem exactly (not being able to install&use my customer's certificate). However, after converting the .crt to a .cer file, and trying to import it into the Authorities list - I get the following message: "This is not a certificate authority certificate, so it can't be imported into the certificate authority list." I converted it by saving it as .cer in several formats. I don't understand why Thunderbird won't let me accept the risk (and the certificate from my customer). thanks very much for your help, Gnospen.