[ssivark]

What UI features do you consider important? I feel that email UI is largely standardized, and the main differentiating factor is speed (and Gmail is definitely not fast).

OTOH, what Gmail does with filtering promotional crap (spam, tbh) is decent, but I haven't compared against other mail service providers, so I can't give a comparative opinion.

[aptwebapps]

Good conversation threading first. For the rest it may just be that I'm used to it but I find it generally much easier to read than, say, Outlook.

[l72]

Do you like how gmail does threading? It’s flat threading and incorrect ordering is why I will not use gmail’s web interface.

[Hnrobert42]

I use the Spark Mail client for that reason.