Fix
The click options (delete, move, mark as spam, etc) all disappear after each message is deleted. This unless I'm selecting all of them at once, which is a slippery slope because the tick box is very small and I cannot say how many times I've accidentally deselected 80 emails by missing it, I have to jiggle the mouse to wake up the options again. Again, frustrating we had to go over to a new UI when the old one was actually quite good, even with the distracting ads.
72nd
ranked