AirMail 3.6.42 (3.6.43) MAS Multilingual | macOS | 56 mb

Airmail 3 is a new mail client designed with performance and intuitive interaction in mind optimized for macOS Sierra! Support for iCloud™, MS Exchange, Gmail™, Google™ Apps, IMAP, POP3, Yahoo!™, AOL™, Outlook.com™, Live.com™ Airmail was designed from the ground UP to retain the same experience with a single or multiple accounts and provide a quick, modern and easy-to-use user experience. Airmail is clean and allows you to get to your emails without interruption - it's the mail client for the 21st century. 

Mac App Store: https://geo.itunes.apple.com/app/id918858936