Fastmail will let you do it for $50 per year if you pay upfront. Just not sure why anyone would run an email server other than extreme paranoia. It’s hardly a set it and forget it affair.
I ran my own mail server for years because I didn't trust Google with _all_ my data. Started colocated server for a while, then VPS, then cloud. Setting up an maintaining SPAM mechanisms on a low volume mail server is a nightmare.
Switched to Fastmail and haven't looked back. Their Android and Web client are great and they've opened their JMAP[0] interface.