I can't sign an e-mail with an S/MIME certificate
I have an S/MIME certificate installed within a USB token. My Mozilla Firefox (User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0 - OS: Windows_NT 10.0 19042) can see my certificate via OS Client Cert Module (path: C:\PROGRA~1\MOZILL~1\osclientcerts.dll). Strangely, Tunderbird did not have such "device" loaded, so I managed to load it via Options->Privacy & Security->Security Devices->Load and typing "OS Client Cert Module" and "C:\PROGRA~1\MOZILL~2\osclientcerts.dll" into "Module name" and "Module filename" fields, respectively. Now I can see my S/MIME certificate and choose it as the certificate for signing and encrypting my e-mails within the account with the e-mail address equal to the one trusted by the certificate.
Now come the problems. When I write an e-mail and try to send it digitally signed, I get the following message box:
--- Send Message Error Sending of the message failed. You specified that this message should be digitally signed, but the application either failed to find the signing certificate specified in your Mail & Newsgroup Account Settings, or the certificate has expired. ---
Well, the certificate has not expired. It is present whithin "Your Certificates" tab of "Certificate Manager" dialog; the entire authority chain is present within "Authorities" tab of the same dialog. I can't figure out what is missing. Other applications (e.g. LibreOffice, PDF-XChange Editor) find the same certificate without complaint and, when required, prompt a dialog asking for the PIN of the token. TB does ask for nothing. Perhaps it doesn't know that a password is required.
Below I give some details of mt TB version.
Any help will be very much appreciated.
Name: Thunderbird Version: 78.14.0 Build ID: 20210901192859 Distribution ID:
Update Channel: release User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 OS: Windows_NT 10.0