And that step is here on HN. That's why it's very relevant to observe that that HN crowd is increasingly happy to support a non-free internet. Be it walled gardens, geofencing, etc.
If you don’t love this approach, Mail-in-a-box works incredibly well even if the author of all the Python code behind it insists on using tabs instead of spaces :)
And you can always grab a really good deal from a small hosting company, likely with decades of experience in what they do, via LowEndBox/LowEndTalk. The deal would likely blow AWS/DO/Vultr/Google Cloud out of the water in terms of value. I have been snagging deals from there for ages and I lost a virtual host twice. Once was a new company that turned out to be shady and another was when I rented a VPS in Cairo and a revolution broke out. They brought everything back up after a couple of months.
For example I just bought a lifetime email hosting system with 250GB of storage, email, video, full office suite, calendar, contacts, and file storage for $75. Configuration here is down to setting the DNS records they give you and adding users. Company behind it has been around for ages and is one of the best regarded in the LET community.
It also depends on how much you are emailing, and who. If it's always the same set of known entities, you might be totally fine with self hosting. Someone else who's regularly emailing a lot of new people or businesses might incur a lot of overhead. At least worth more than their time than a fastmail or protonmail subscription or whatever.
Throughout 20 years of running my own mail server for companies, friends, and myself, the additional effort to get commercially-run mail servers to accept mail was both annoying and random ("oh, look, hosted Outlook has started rejecting our mail again..."), and sometimes they don't even send a standard response but just "accept" and blackhole the email. Eventually you find out that someone else in the /24 you're in at Rackspace or DigitalOcean is happily running an open relay, and that's why your IP is having problems. Or any of a dozen similar things.
In 2019, having gotten very tired of this, I gave up and moved my mail handling to Amazon Workmail and SMS, and after setting it up properly once, it's been trouble-free and maintenance-free for half a decade. Compared to some solutions, it's expensive, but not in absolute terms.