You can't replicate Gmail, but with Mailcow I've gotta say the whole process is pretty seamless. You can throw it onto a 5 euro VPS at Contabo, run docker-compose up and be done. Just regularly run the update and backup scripts to make sure you're up to date but that's it, really.

Exchange ActiveSync, multi domain + multi aliases with catchalls, (temporary) aliases, mail delivery rules, TLS requirements, you name it, all configurable in the web UI. There's even a built in DNS checking tool to verify that all the necessary records are set up right.