thunderbird

Install command: 
brew install --cask thunderbird

Name: Mozilla Thunderbird

Customizable email client

https://www.thunderbird.net/en-US/

Development: Pull requests

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

Cask code: thunderbird.rb on GitHub

Current version: 148.0

Requirements: macOS >= 10.15

Conflicts with casks:

thunderbird@esr 140.8.0esr Customizable email client Mozilla Thunderbird ESR

Analytics:

Installs (30 days)
thunderbird 1,576
Installs (90 days)
thunderbird 4,631
Installs (365 days)
thunderbird 18,213