I am self-hosting my email. It's a pain in the ass, but software like mox[1] help on keeping things easier. The most tedious part is to setup correctly SPF, DKIM and DMARC and ensure that your IP will be whitelisted.

[1] https://www.xmox.nl/

I was looking recently and it seems there is something new that appears extremely easy to use on the surface: stalwart[0].

Not an endorsement as I haven’t actually tried it myself.

[0]: https://stalw.art/

How do you protect your server? Any guides there?