[yanko]

Run a dns server like bind first to serve locally only defined and host zone if a domain home.lab In the zone define it's dns server and a and mx records with mail.home.lab which can be same server Install SMTP server like postman Configure to serve emails as local for home.lab and you are set

[yanko]

Of course DNs server to act also as resolver to forward for other DNS requests and also set the dns server as default for all servers in the lan, can be distributed by DHCP as well