I’ve followed the instructions for exporting the cert store cert to a file and importing it into Thunderbird. I can see the cert if I use the thunderbird certificate manager to view certificates (the only thing that looks odd is that the purpose is “”. When I try to sign an email “you need to set up one or more personal certificates before you can use this security feature. Would like to do so now?” pops up … to which I click Yes, which brings up the account settings dialog selected for security tab. If I hit select on signing I get the mesage “Certificate Manager can’t locate a valid certificate that can be used to digitally sign your messages.” Similar message for encrypting.
Where did I go wrong?!