I'm going to plug fastmail. Rationale:
(1) tech support that actually reads your messages and replies with a solution demonstrating comprehension of the message that you wrote. Amazing. I've emailed them twice and gotten a great response both times.
(2) it is the best UI I've seen outside gmail;
(3) They have continued actively developing their UI, with nice updates released perhaps in the last 6 weeks.
(4) keyboard shortcuts that work
(5) Instead of inbox 0, I practice inbox 50k and it handles it fine.
(6) I just had a decade-anniversary there and I've never regretted it.
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