Over time I realized that residential IP blocks were banned on most servers. I moved my email server to a VPS. No luck. I quickly understood that self-hosting email was a lost cause. Nevertheless, I have been fighting back out of pure spite, obstinacy, and activism. In other words, because it was the right thing to do.
But my emails are just not delivered anymore. I might as well not have an email server.
(After self-hosting my email for twenty-three years I have thrown in the towel, Carlos Fenollosa, 2022)"
From the article, quoting this other article
https://cfenollosa.com/blog/after-self-hosting-my-email-for-...