postalserver/postal ? reverse-engineered prompt

Build me a complete, open-source mail server that I can run myself. It should be a self-hosted alternative to commercial services like Sendgrid, Mailgun, or Postmark. My websites and web servers will use it to handle both sending outgoing email and processing incoming mail.

I need a full web interface to manage the whole system. From the UI, I should be able to see delivery statistics, check message logs, and get reports on things like bounces. It should be a robust platform, not just a simple relay. Please build it as a Ruby application and set it up to be deployed with Docker, so it's easy to get running on my own infrastructure. You can check out the Postal project for a good reference on how it should all work.