I'm a proton unlimited subscriber. Can't recommend these guys enough. Customer support is always excellent, very capable guys no matter if you're on Android or Arch Linux, these guys know their shit. They have a black Friday sale every year but for protonvpn, protonmail, simplelogin premium, 500gb storage. Everything e2ee, I mean, what can I say but they're an amazing company.
I’ll second this one. I love Proton. It’s the only free service, other than the late Apollo, that I’ve ever decided to pay to upgrade just because I love it so much. It also happens to be well worth paying for imo.
As with any service, unless you build and host it all yourself, you’re ultimately trusting some one else with your data. However, Proton are generally very transparent and, as you say, seem to really know their shit. For those reasons I choose to trust their services.
It really saddens me they changed their domain to proton.me it looks so wildly unprofessional and spammy while protonmail.com looked professional and even futuristic/scientific. Such a bizarre decision especially since everything else they do is so great
"Private" and "email" should really not appear in the same sentence. The email protocol was not designed with privacy in mind, so any company offering you a "private" email service is simply pandering to the privacy-conscious crowd. Yes, some may promise to store your messages with "zero access encryption" and end-to-end encrypt messages between users of the same service but unless you're only messaging those users (not gonna happen) copies of all your messages will be hanging around on much less secure/private servers.
Tutanota, Protonmail and Lavabit are currently the most known services promising private email (I have personally opted for Protonmail because it's free and does not require invites) but you're making a mistake if you want to use email for any sort of private or confidential communication. Use mail to create an account on with a service designed with privacy in mind, sure, but don't try and twist email into something that it isn't - you will regret it.
My general philosophy with email is to use a service which would go out of business if it was found out that they've been giving 3rd parties access to your messages and even then don't store anything sensitive on mail. The ones mentioned above will do fine for that.
I like Skiff but I sent two emails with my Skiff email to my brother, but they never appeared to his email (checked spam and searched too). Only reached to him when I used my gmail address.