Can you recommend a paid mail service which is better? I'm in a search process now, to ditch google as much as I can, and was leaning towards Proton services.
Hey isn't for everyone, it's quite quirky and opiniated. Fastmail is more a classic email experience. I personally like the style of Hey and some of their unique features such as Screener and Collab.
I've been using Tutanota for the past several months, and the experience has been exceptional! I highly suggest checking them out. They even have free accounts now (when I signed up, it was pay-only).
Happy Fastmail customer for 10 years or so. They are quite focused and do a great job. My only complaint is their mobile app: I wish it worked offline. I've used K-9 to work around this, but don't feel like I should have to.
I guess it depends on which parts they need to be better.
From a functionality standpoint I would list, hey.com, fastmail and icloud as better. mailbox.org is better on being a traditional mail host you access using your own client (no wierd bridge app). hey.com and icloud are US hosted if that matters to you.
For the semi selfhosted options https://thehelm.com seems like a really good option.