forget about self hosting email... I tried it for years, and even if you get it working (needs months), it will eventually stop working again. The problem is that in order to get the big boys to accept you as an email provider, you have to jump through infinite hoops, and be treated like a criminal and/or scammer in the meantime (or at best a business that is trying to send newsletters). You will never get a human to talk to, it's just an infinite loop of automated processes.

Anyway, the problem is "trust" which boils down to IP reputation. And since we are all still on ipv4, your IP was reused. Which means you need to spend months cleaning it. And you won't have a guarantee that you won't lose this IP in the future.

Not who you asked, but I self-host some non-critical mail domains using Mailu[0], which is a set of docker containers. It's been fairly low maintenance. Ease of setup depends on your technical knowledge, but if I can do it, and you're on HN asking the question, you'll probably manage.

[0]: https://mailu.io/

So, now you have to worry about your VPS/Internet provider deplatforming you. Or about your domain name being seized. And spam filtration, backups, redundancy...

I'm not saying email self hosting should not be done, I just say a bit of planning should be done.

DNS seems like the most annoying part, it is SPoF by design. The problem can be mitigated, but seems like cannot be solved. For example, owning multiple domain names in multiple jurisdictions. And round-robin them. You cannot eliminate SPoF for any one specific service you want to login using email. But you won't lose access to everything at once.

Edit: P.s. At the same time, owning your domain for mail seems to be one of the most impactful things to do to reduce digital serfdom. Banned at *mail? Just switch those MX records and go on.

OpenSMTPd + Dovecot is extremely easy to setup and maintain.

For my parents, I registered a domain on OVH and they use the free email accounts they come with. So that's an independent, ready to migrate, email account for about 8 euros per year.