Have you considered GrapheneOS? Not an open source phone as you say, but it is at least open source software, running on hardware with published specs. It should be capable of everything you want.

Has anyone here used Mox? It looks interesting, but maybe a little immature.

I have been using modoboa, my installation is fine as far as it goes, but coming up a little short technologically these days, and the upgrade path is total replace. If you have or install Docker on your server, there are poste.io and docker-mailsever,which both look good. Running your mailserver in a container or VM is almost essential, for security, and so you can blow it away and start over if you make a mistake.

Running an email server is not necessarily hard, but it is stressful: if you have other users, even family, they will take it for granted when it works, and complain loudly when it does not. Like any server that others use. But, beyond security, I have a certain stubborn geek machismo about it, it’s a level of sysadmin above basic.

1. Control and privacy. The server does exactly what I choose, not somebody’s business model.
2. Once you have other users, it’s not a hobby anymore. People are not amused by downtime.
3. The w3schools.com tutorials have been good for me.

I used a PineBook 2 as a secondary machine, daily, for a couple of years. I never felt constrained by the CPU architecture, barely noticed it mostly. I stopped using it because it fell apart physically, but it was perfectly stable. I’d get another if I could get a sturdier one.

Piracy is increasingly becoming the only reasonable answer.

Two things, one you care about and one you might not. The one you care about: you can set up a service in isolation. You can then test it, make sure it works, and switch over to it once you are sure, with almost no downtime. This is important for things you actually need to use. Once you do something like breaking your primary email server, you will understand. Also, less important, you can set up a service on, say, a VM at home, and move it to a VPS, without having to transfer the entire image, and it will work the same. The one you don’t care about. That last bit about moving servers around is important for cloud providers who turn these things on and off all the time.

name.com. I don’t remember why I picked them, but they do no BS and the service is fine.

Likewise. I have been running it for years, almost no problem that I can think of. My setup is pretty vanilla, Apache, MySQL. It’s running in a container behind a reverse proxy. I keep it as up to date as possible. Only 3 people use mine, and I don’t use very many apps: files, notes, bookmarks, calendar, email.

Everything in a corporation exists to benefit the corporation.