Bro, I owned a /23 at a colo for over 10 years. Registered my ip space with ARIN, had abuse contacts, setup a mail server on a /27 on a /24 that remained mostly unused outside of dev and test servers (strictly controlled). The mail server was also strictly configured to never emit a single email that wasn’t sent by me. So no forwards, no bounces etc.

Mail server still gets blocked by random domains. Nope. Done with hosting email. Everyone assumes you are spam and won’t accept your mail unless you pay them (to be your mail provider).