The reason why nobody runs their own email server anymore is because it's literally impossible to do so if you want to have any hope of your email actually reaching the intended recipient.

https://fountain.fm/episode/3Bd1tcxwgykW0G7d0P1f

nostr:nevent1qvzqqqpxquqzp07ahd3u8tmwcjfvz6y5kzz579dpd4xwjl93al0x4qe97jh4tptmwr4705