With the recent news of ProtonMail, I would like to remind you that ProtonMail has been a honeypot for a while. Just look at their transparency report on their website. They also don't allow you to generate private GPG/PGP keys client-side (the only person who should have access to your private GPG key is you).
Anyway here are some alternatives I recommend (not sponsored by any of them):
* Fedora Mail (https://fedora.email/) (Registrations are currently disabled) - An email service run by @j who also runs bae.st. It's funded by donations, supports mail clients, and even the ability to encrypt clear-text emails in your inbox using your public GPG key.
* Disroot (https://disroot.org/en) - Run by @muppeth, along with other volunteers. Provides a bunch of services including email. Supports custom domains if you donate. Free to use for non-commercial purposes.
* Posteo (https://posteo.de/en) - Paid service (1 EUR/month). Hosted in Germany. Accepts payments in cash via mail. Offers the ability to encrypt your inbox, contacts, and spam folder using your password.
* Self-hosted - Do your own research. Only recommended for those with the technical knowledge.
Granted, you should never trust any provider because you never know what they are doing unless you have physical access to their servers, but these services seem to be a lot more trustworthy than ProtonMail, Tutanota, and other honeypots.