This isn’t as hard as you might think. I pay for https://mailwip.com because the founder helped me figure out mine. It was ultimately relatively strait-forward. I stay because I appreciate his work, my email is flawless, and I like the logs they provide.
I've been self hosting email for a few years at this point and haven't had any delivery issues. Just make sure you set up all your DNS correctly and avoid polluted IP ranges like DO or AWS