Don't use the file storage or notes features very often, though. But they're quick and easy to use when I need them.
[^1]: https://www.fastmail.com/blog/fastmail-calendar-updates/
I think the most important part is having your own domain so you can switch whenever you want, but that's also the most difficult part.
What I did is to keep both emails and slowly migrate service by service. Nowadays, my Gmail is mostly spam and all the important things are in my custom domain, so I just check my old email once or twice per month in case there's something I've missed.
I chose it because it was recommended so often here, and I find it's an easy replacement for gmail and I no longer have a fear of my google account getting shut down.
Mainly I didn't want a 3rd party in control of my email. If I don't like fastmail in the future, I'll pick another provider and update the MX records. No big deal.
I don't trust the long term viability of Google products anymore, including Gmail.
I love that fastmail can handle any.name@my.domain
1and1 for the backup address I almost never check
The ability to screen emails and approve new senders has been a game changer for me. I've managed to cut down on noise and actually hit Inbox Zero for the first time.
The spam protection isn't great, it relies on proprietary APIs, and I'm not super excited about the other features, but I'm sticking with Hey just for the screening feature.