WHAT IS SMTP?
SMTP (Simple Mail Transfer Protocol) is an industry standard for sending emails. Proper SMTP configuration helps increase email deliver ability by using authentication.
Popular email clients like Gmail, Yahoo, Office 365, and Zoho are in a constant battle with email spammers. One of the things they look at is if an email is originating from the location it claims to be originating from. If the proper authentication isn’t there, then emails either go in the SPAM folder or worst, or don’t get delivered at all.
Hence, LK Domain Registry advice that fully Patched Version: 1.4.3 site owners to install the latest updates