Setup web and mail server on 2 different droplets
I have already setup nginx web server on a droplet and it's running fine. I have also setup mydomain.com to point to the droplet (Droplet A). Now I would like to run a mail server on a separate droplet (Droplet B). How to configure the DNS / MX records so that Droplet B receive mail for mydomain.com while droplet A serves the web?