Postal a fully featured open source mail delivery platform for incoming & outgoing e-mail. Postal is a complete and fully featured mail server for use by websites & web servers. Think Sendgrid, Mailgun or Postmark but open source and ready for you to run on your own servers.
Homebrew-Core default formulae for the missing package manager for macOS. Just
brew install <formula>. This is the default tap for Homebrew and is installed by default.