I can’t recommend Migadu enough.

The most important thing, if you intend to do outgoing email, is to get a reputable hosting service, where you'd have few/none bad neighbours. Unfortunately that often doesn't come together with cheap, as cheap solutions often attract a certain clientele. I've also had more luck with slightly smaller (but still reputable) providers, i.e stay away from OVH / Hetzner and the like. If you want something cheap, it'd probably not be a good experience to self-host.

With my self hosted solution I have no concerns about deliverability, and only very few occasions had blacklisting issues (due to neighbours in the /16 range).

https://tunnelbroker.net/

Get a static IP and host yourself? Hurricane electric offers free IPv6, so you can get a static IPv6 address for your mail host

Free/cheap VPS are a lot more likely to have their IPs blacklisted for email, due to being used for spam.

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

The recommendation to use a reputable email provider host is much better, but if you want to go it yourself the Google Cloud free tier includes an instance with a public IP address. Snapshots are not included in the free tier or any other backup, so use at your own risk - this besides the complexity of email security.