They’re both excellent, but I prefer Proton because I need to be able to take reliable offline backups of my mail accounts & sync to a standard mail client. I can bridge and archive copies with Proton… last I checked, Tutanota lacked those features.

I’ve never used Tutanota but been a Proton Unlimited user for a few years now. I definitely like the mail service, and Drive and VPN are nice but can be slow, especially Drive. Everything else I don’t have much use for, and honestly I cringe when I see the new stuff they’re working on. Not that any of it’s bad, but it feels like they’re in the “can’t just make a good product” camp, constantly trying to add on new stuff instead of focusing on quality. Could have it all wrong, though, I’m just a person, not an analyst.

Both are ok, but Proton is too weird, also IMAP issue for Linux users makes it even worse. Posteo is probably better service, than both combined.