My daily email app
I use AirMail daily (in fact, just deleted the other mail apps, including Mail) from my iPhone. Havent seen the issues the other reviewers have mentioned (and hopefully didnt just jinx myself). But, I use any mail client for going through my inbox, sending actionable items to OmniFocus (The reason I use AirMail instead of Mail), and either archiving or deleting the message. I also use delayed send (aka "undo"), scheduled send, and Markdown. Thats it. And, given that use, AirMail handles it all well on iOS and MacOS. Being able to set up a new device just by importing setting synced via iCloud is handy too.
G-Mo about
Airmail - Your Mail With You, v1.6.4