Mail servers speak with other mail servers to exchange mail. There is no authentication involved in this. So the only security that you may be interested in is encryption. And that is not somthing unique to proton mail.
2FA is nice for ‘apps’ but has nothing to do with the security of your mail once it actually leaves your machine. My ‘single factor’ auth mail to MY mail server with encrypted headers and gpg content is about as secure as it gets. But even that is only as secure as the crypto you get with gnupg.
If you can only use the service with a special app and still send mail to ‘the rest of us’ you are being had.
If the encryption is not based on public key crypto, then how do others read your mail? Well, of course, they can’t. So, proton is saying they’re doing ‘better’ transport encryption on they way to ‘them’. Well, that’s ‘useless’ ™.
Now I’m only saying that as someone who has managed mail for many tens of thousands of users. I didn’t do it as well as proton, probably
As to the bridge itself and QT. It seems to be written in GO. This, in it self is ‘a good thing’ ™. I like go. But compliling this in the sailfish context is going to be ‘non-trivial’.
The whisper fish rust project is a demonstration of just how difficult this is. I haven’t gotten around to that in a really serious way, but that’s also supposed to be a security ‘thing’. However, it’s a massively bloated project which is very probably very insecure. Just look at this:
8.0K |
/usr/bin/harbour-2048 |
244.0K |
/usr/bin/harbour-advanced-camera |
8.0K |
/usr/bin/harbour-audiocut |
8.0K |
/usr/bin/harbour-defender |
808.0K |
/usr/bin/harbour-fahrplan2 |
336.0K |
/usr/bin/harbour-file-browser |
80.0K |
/usr/bin/harbour-fishtheke |
8.0K |
/usr/bin/harbour-gameoflife |
224.0K |
/usr/bin/harbour-hafenschau |
8.0K |
/usr/bin/harbour-newsapi |
212.0K |
/usr/bin/harbour-pure-maps |
8.0K |
/usr/bin/harbour-quantofa |
24.0K |
/usr/bin/harbour-sailfishreboot |
80.0K |
/usr/bin/harbour-sailhn |
32.0K |
/usr/bin/harbour-screenshot |
8.0K |
/usr/bin/harbour-scribble |
8.0K |
/usr/bin/harbour-simplecrop |
8.0K |
/usr/bin/harbour-simplemahjong |
348.0K |
/usr/bin/harbour-storeman |
544.0K |
/usr/bin/harbour-taot |
244.0K |
/usr/bin/harbour-tidings |
152.0K |
/usr/bin/harbour-videoPlayer |
18.4M |
/usr/bin/harbour-whisperfish |
21.7M |
total |