Not if you want your emails to be reliably delivered. Even if you set up all of the right things and follow all of the rules, you will probably always be fighting to stay out of the spam folder.

https://cfenollosa.com/blog/after-self-hosting-my-email-for-twenty-three-years-i-have-thrown-in-the-towel-the-oligopoly-has-won.html

I had a similar problem and was unable to find replacement parts, so I replaced the whole spigot.