Jeffrey Mincey nails the best email apps for Mac, iPhone, and iPad.
For now, Airmail is what I use (along with Apple Mail) but I would use Newton if it were affordable. Spark is the easiest to use but has security issues and uses bandwidth by the bushel. Canary has more security options, but is new and untested.
I’ve tried all and totally agree. Airmail is very good. Spark has a great interface. Newton has the best features. Canary is too new to tell, but has good security options. I’d like one email app that did what they all do best.