mailsteward

Install command: 
brew install --cask mailsteward

Name: MailSteward

Email management tool for Apple Mail and Postbox

https://mailsteward.com/

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

Cask code: mailsteward.rb on GitHub

Current version: 18.1.1

Requirements: macOS >= 10.15

Analytics:

Installs (30 days)
mailsteward 2
Installs (90 days)
mailsteward 8
Installs (365 days)
mailsteward 17