> The Internet is generally not anonymous, and if you are breaking Swiss law, a law-abiding company such as ProtonMail can be legally compelled to log your IP address.
The "Threat Model" blog post is linked from their main site.
And then you just let it run for 10 years without doing any more work and it just rots away.
Not recommended
If you are attempting to leak state secrets (as was the case of Edward Snowden) or going up against a powerful state adversary, email may not be the most secure medium for communications. The Internet is generally not anonymous, and if you are breaking Swiss law, a law-abiding company such as ProtonMail can be legally compelled to log your IP address. A powerful state adversary will also be better positioned to launch one of the attacks described above against you, which may negate the privacy protection provided by ProtonMail. While we can offer more protection and security, we cannot guarantee your safety against a powerful adversary.
A blog post from May 2014 isn't sufficient, no matter where it's linked from.
If its something you care about, you should not be making your choices on the basis of marketing splashes and you should certainly not need your email provider to explain Tor to you.
I want the benefits without being a mechanic. And I'm willing to pay money for it. Lots of money.
Proper Opsec for dissidents requires multiple layers and technologies and simply cannot rely on a single vendor. Any proper company accepting credit card payments is going to be subject to court orders and there are limits to their ability to resist them.
Protonmail has taken extraordinary measures to limit their exposure to those risks but anyone who is assuming they can e.g. be an enviro-terrorist or CCP dissident and be safe solely because they use Protonmail is terribly naive and ignorant..