This might be obvious and not need to be mentioned, but if you're self-hosting, don't forget the obvious and often most flexible option: A Linux box directly running plain old Exim (or Postfix, etc.), Dovecot (or Courier, etc.), Spamassassin. No containers, no abstractions, no meta-configuration.

I've had this setup for a couple of years now and it's not failed me. Support TLS, SPF, spam checking, DKIM, can support multiple domains and aliases. Basically anything you can imagine. And, despite the FUD you might hear about not using a cloud service, my mails don't get magically lost into people's spam filters. The initial configuration/learning is steep, but I pretty much never have to touch it once it was working.

Do you recommend any guide or book on the subject?

Mostly online searches and reading the software's documentation. Unfortunately there appears to be no site that walks you through the entire process. You'll find "how to set up exim" tutorials and "how to get dovecot working with exim" but so far I have found no overall soup-to-nuts guide that matches my exact configuration.

1. You need your own domain

2. If you're new to Linux, I'd set up something simpler first, like a web server just to familiarize yourself with your domain tools and your distribution's configuration.

3. A good half-way solution for migrating from Gmail is to set your own server as MX for your domain and forward received E-mail to Gmail. That way you can get familiar with setting up your MTA without worrying about delivery. And, you can start encouraging people to start sending mail to your @domain.com address rather than @gmail.com address. I had this set-up for years before taking the plunge and hosting everything myself.

Be warned, Gmail applies very aggressive filtering to your incoming forwarded mail, even before it reaches your "Spam" folder. This was one of the primary reasons I decided to self-host: I was finally able to compare the list of E-mails I received, through looking at my logs, to the E-mails that ended up making it to Gmail. Gmail's (presumably) spam-filtering was filtering out an unacceptable amount of false positives.

4. Set up your host to deliver locally. You'll be able to verify it's working by using standard unix mail tools running on your host.

5. Set up something nicer for delivery like IMAP, and get your favorite mail client to work. I use Dovecot, but there are plenty of options.

6. Any bells and whistles you want. TLS, SPF, DKIM, Spamassassin, multiple domains. I found at first I was getting a massive amount of spam (thanks for fixing this for me for years, Gmail!) but after a few months of training, Spamassassin is very good and I'm back down to not seeing much anymore.

Hope that helps. To your other question. I spend $5 a month for my VPS, and I can host a lot more than E-mail there.

Also, what's your monthly cost?

> https://mailinabox.email/ - no docker, no multiple domains, roundcube, nextcloud for groupware. Main disadvantage or advantage, depending on your perspective is that you need a mailinabox server per domain.

Are you sure? I am running mailinabox and have multiple domains and accounts with no issue.

Same here. Ran many domains on a single server for a long time

> And then this is the more hands on version, which I guess would be sovereign as ansible deployment.

I used to run a Sovereign box.

It served me well for 2-3 years, but it got too cumbersome to maintain: they changed their approach to various configuation things (for the better, I'm sure), and threatened to break my setup in the process.

All told, it felt like it had missed the sweet spot between pre-configuration and flexibility, in the end not quite giving you either.

> IMHO sovereign puts too many attack vectors on a single machine.

I turned off most of the attack vectors (I didn't need all the bells and whistles). But yes, they tried too hard, and over-complicated the setup as a result.

There is also https://cloudron.io/ to self-host, which provides a complete email solution based on dovecot and haraka plus a couple of webmail apps to use, like rainloop and roundcube.

I currently use mailinabox for several domains on one server. Works like a charm for me.

You can have multiple domains in mailinabox. Its not clear from the UI but you just add a user with a different domain name and it adds it.

I would like to add to this list iRedmail: https://www.iredmail.org/

It deploys mail server based on modern software stack on your box and you can customize it to fit your demands using recipes suitable for well-known software.