If you're serious about hosting your e-mail, check out this guide. https://workaround.org/ispmail Someone on here (Lurker404 IIRC) shared it with me.

I had run mail and web servers before many years ago, and it helped me a ton. There's a lot of extra things to worry about like firewall, security, DKIM, etc. I've been set up for a couple months now on a $5/mo cloud VM. Incoming mail works flawlessly, every now and then I get a bounce on outgoing mail but it's been fixable. The only think I didn't set up was webmail. I might eventually but it's just me using the server and I don't really need it. It goes over a lot of security concerns too, that you should take into account. For example, the fail2ban tool that blocks IPs that try to brute force my SSH password is up to like 6000 IPs blocked. I have to have SSH for remote access and even moved it to a different port. It doesn't matter.

I would not run it on a home server without a static IP though. It's not for the feint of heart but if you like playing with these things it was fun and I'm not on big tech anymore. I've since set up WebDAV for cloud syncing my notes app, and am working on a website that will probably be crap (but fun for me). I'm also going to run a matrix server even though I have no current need to use matrix, because I can! I've got a few other things I want to try too. Right now my $5/mo VM isn't even in the ballpark of being overloaded and I use like 5GB of my 1TB of download.