There's other efforts out there like mailinabox, iRedMail, but everything really is relying on the same components which come with the same burden when you have to dig into the configuration to fix problems.
The dream is a single executable that does IMAP, SMTP, webmail, admin interface, automatic TLS.
Right now if you want to move away from e.g. Gmail, you're going to end up either going to another hosted solution or investing a whole bunch of time in configuring one yourself (and likely giving up if you're not already a sysadmin of some kind)
@mfashby I would love something simple and stable enough that I could just set it up and be confident that I could just leave it running and my email would be reliable. That's the main thing stopping me from self-hosting.
Sunbeam City is a Libertarian Socialist solarpunk instance. It is ran democratically by a cooperative of like-minded individuals.