@kitten be prepared to also get frustrated about DNS records and whatnot, those are also required to be properly set up otherwise you run the risk of having your mail arrive in someone’s spambox more often than it should
@kitten ive been told so many times this is too much of a hassle to be worth doing, because of the intensity of spam filters. i had a small email server set up at my last job, just for automation alerts and whatnot, and it was always flagged as evil by our work filter. i had to get our own ip allowlisted.