Thunderbird can't read encrypted email

I installed the latest version today and it scanned al my email. I had to restart and than I send a email to myself and got this from Thunderbird. Its Dutch but I try to translate a bit.

The popup window says:
This email has no digital signing from the sender. It could be send by someone els or it is dameged.

This email is encrypted but can’t be decrypted. There is a problem with the decrypt key.

Thunderbird says:
TB could not find the decrypt Key

Hi Eljo,

Have you signed up for your free certificate? Open “SecureEmail Configuration” from START>>PROGRAMS>>COMODO>>SECUREEMAIL.

Click on “Certificates” on the left and then Click on “Sign Up…” on the right side. This will take you to the Comodo Email Certificate Sign-up page where you simply input your name and email address. It will then send you an email telling you that you can collect your certificate.

Simply click on the link and download and install the certificate following the instructions.

You’ll probably have to reboot but once you do, it should be working fine.

P.S. If you have already got your certificate and this is still and issue, check in Thunderbird to see if the certificate has been installed in Thunderbird (


With the install there is a cert. made and installed, but not in Thunderbird! How do I get this cert in Thunderbird?

See the following link. The beginning instructions shows how to import it.

Also check that "Digitally Sign Messages (by default) doesn’t have a tick next to it and that the Encryption on the same page is set as “never”. Comodo Anti-spam does the signing for you.


Works Now :slight_smile:
Thunderbird cert import has another password than the cert I wanted to import.

Great news that your issue has been resolved!