What is the encryption used to encrypt the subject in Thunderbird email? I know the PGP is used to encrypt the body/attachments of the email. Is PGP also used to encrypt the subject? If not, what is used for encryption? Is it something like AES256 or something else? I tested this out with others that do/do not use Thunderbird. It seems that the ... that appears when the subject is encrypted is no problem when the other person also uses Thunderbird and they can read the subject but when a email is sent to someone not using Thunderbird and do use PGP they can open the body of the email and read the details and get attachments but they cannot view the subject, all they see are the ... in the subject area. This is one of the reasons I'm interested in the answer and also to be able to explain to others why they should start using Thunderbird so we can have encrypted subjects also but I need to know the technical details of the encryption usesd for the subject data. The more details and/or links to articles about this would be great, I've tried looking before sending this message but cant find details about this. Thanks for helping!