mailspring

Install command: 
brew install --cask mailspring

Name: Mailspring

Fork of Nylas Mail

https://getmailspring.com/

Development: Pull requests

Cask JSON API: /api/cask/mailspring.json

Cask code: mailspring.rb on GitHub

Current version: 1.19.1

Requirements: macOS >= 12

Versions:

Intel tahoe 1.19.1
sequoia 1.19.1
sonoma 1.19.1
ventura 1.19.1
monterey 1.19.1

Analytics:

Installs (30 days)
mailspring 80
Installs (90 days)
mailspring 244
Installs (365 days)
mailspring 700