I'm having trouble understanding why you posted this when it's just the mirror of the actual repo on gitlab[0], AND the page is really just config details, not a lot of description.. but then I notice you've posted the marketing website[1] several times and it just hasn't got traction. Fickle HN votes, I guess. For my money, I find https://lightmeter.io more useful, even the video intros.
A mail server is one of those things I consider way too important to trust myself with. How do you run one without constantly worrying about it being compromised?
[0]: https://gitlab.com/lightmeter
[1]: https://lightmeter.io/