mailspring

Install command: 
brew install --cask mailspring

Name: Mailspring

Fork of Nylas Mail

https://getmailspring.com/

/api/cask/mailspring.json (JSON API)

Cask code on GitHub

Current version: 1.14.0

Requires: macOS >= 10.13

Analytics:

Installs (30 days)
mailspring 66
Installs (90 days)
mailspring 153
Installs (365 days)
mailspring 730
Fork me on GitHub