The VPS is required specially if you, like me, are behind CG-NAT with no way to escape from it. Using a VPS (or any other kind of server with a public IP). Using a VPS is the cheapest option…
residential IPs can be blocked for ports like 80, 443, 22 and the email ports in general (25, etc), using a non-residential IP could give a better experience. Moreover, even if not behind CG-NAT, having a public static and not-changing IP is a good advantage.
Everything is hosted locally! the VPS is only a tunnel between internet and the home server.
You should always setup logrotate. Yes the good old Linux logrotate…