So I am trying to work on a fork that support emailing users announcements we have for administrators (see Mail-in-a-Box Mailing List ).
Anyways, I am trying to get an “example” email sent to myself, but I’m trying to digitally sign it (WITHOUT ENCRYPTING IT) with Thunderbird, but I can’t seem to figure out how to do that.
Now, as far as I know, there are no certificate authorities that will give certificates for email signing that will do it for free, so I tried creating my own certificate authority, and my own certificate signed by my own certificate authority, having Thunderbird trust the CA, but it never seems to work.
Here is what I’ve tried:
Here is my command prompt for trying to create the CA: https://paste.ubuntu.com/p/wpvSjZHdYj/
I did not password/passphrase anything.
In Thunderbird, I have Enigmail installed, not sure if that is relevant here.
Under Edit -> Account Settings -> firstname.lastname@example.org -> security:
If I click “select…” under “Digital Signing”, I get this error:
“Certificate Manager can’t locate a valid certificate that can be used to digitally sign your messages with an address of email@example.com.”
So I tried clicking “Manage Certificates”, and then “Import…”, navigating to my “CA/ca.crt”, clicking “open”, then checking both boxes: “Trust this CA to identify web sites.” and “Trust this CA to identify email users.”, then clicking “OK”
Then I tried click “select…” under “Digital Signing” again, and no luck.