Get Thunderbird (or any other standalone email app). Extremely traditional UI, and better responsiveness due to no frill JS and no tracking.
Bonus, even read your emails offline!
<s>Innovation!</s>
Bonus, even read your emails offline!
<s>Innovation!</s>
It does have per-account adjustable syncing periods, and you can click a big ol' button to refresh immediately.
(They did spin off Opera Mail as a separate app, but I see no point in it, since it's just Opera 12 with the browser part disabled).
It's a bit clunky, but it's the best for serious people.
It was/is great, but I didn't find a compelling reason for myself to shell some bucks over their way vs. using Opera Mail or Thunderbird. What are the killer features for you?