I also came here to suggest fastmail - it's been great overall, and the killer feature that allowed me to transition to it smoothly was that they offer email sn

I also came here to suggest fastmail - it's been great overall, and the killer feature that allowed me to transition to it smoothly was that they offer email snoozing, which I use to manage my schedule and when to deal with emails, etc. That was the great feature of inbox that I felt I couldn't leave until they killed it and sent me back to gmail (whose interface I don't like, and I want to de-google as much as possible, so it fitted together well).