Many other guides dive deep into 10 plus pages of how to set up such a service with Dovecot, Postfix and a web server all from the command line, but this one is a lot simpler because most of what you need is inside Citadel. Citadel also has calendar, Contacts, Notes, Tasks and chat rooms so can be a good alternative to Google or other providers. Your only cost really is the Raspberry Pi and a domain name if you don't already have one.
You could tweak this a bit further by using your own DNS provider (or alternative to Cloudflare) and considering an external hard drive connected to the Pi for reliability.
See https://pimylifeup.com/raspberry-pi-email-server/
#technology #email #privacy #raspberrypi #alternativeto #opensource
So i never heard about citadel project before... From their Code of Conduct (or lack thereof):
Not that i identify with this SJW label, but my interpretation is they're pretty happy without most of us :)