I’m not sure I really get the pull. It seems to just be a matrix server with bridges and custom clients
They do have their work open sorced which is nice, but this all kinda just looks like what matrix is on its own. I guess the only advantage I see is maybe making things a little easier for more casual folks, but it does cost to…
I feel like you’d get this with the Protonmail Bridge. It acts as it a email provider on your local network, and handles the encryption stuff itself. I believe Thunderbird sees and stores the email it sees through that as plan text.
https://proton.me/mail/bridge