Maybe, Apple Mail is good, again, I don't know as I'm not using Apple, but I don't know any client for Windows and/or OSS with Windows support which has as basic features as support of per-folder settings (identity, sorting mode, etc.) stored on server or proper support for Sieve. In my eyes it is basic features.
And don't let me start to rant about message editor itself, especially in text-only (as opposite to HTML) mode with proper quoting & such.