Has promise, but major flaws
I have to compare this to the standards. Inbox and Gmail for me. Airmail comes so close in its approach. Very customizable. Sleek. Offline use a nice feature (though really dwindling in significance, given 24/7 connectivity). Major issues are subtle bugs (e.g., subtle but sometimes very noticeable formatting differences when comparing to Gmail). Finally the biggest issue is simply the search tool. Online search does not return all hits, easily confirmable with a comparison to search in standard clients like Gmail. If I cant be assured to find emails and resources in my inbox then it is not usable for me. Might try again after update and see how it goes.
RogerDarn about
Airmail - Your Mail With You, v1.6.4