SMTP is short for Simple mail transfer protocol. It is just a networking procedure that allows your Pc to deliver emails to other receiver email clientele like Gmail, outlook, yahoo, and so forth via the internet. it is as simple as that. Take note: Create a file under /etcetera/apt/sources.listing.d, https://whmcs-install43332.thenerdsblog.com/32284344/getting-my-vps-support-service-to-work