Boxy

Boxy 2 is the first major update to the powerful and minimal email client for Mac, powered by ‘Inbox by Gmail’. It features a redesigned interface, revamped multi-account and notification system, new themes and features, and tons of improvements.

Boxy is the best Inbox by Gmail client for Mac, with a sleek and polished interace, and many native features like Push Notifications, Reader Mode and Markdown Support.