Interesting article but needs a bit more depth, for instance it mentions incredibly briefly the MX record
> The PTR (or reverse) record query is used to validate that the IP address is assigned to the same host that is resolved in the Mail eXchanger (MX) record query
It does not explain that when you try to send an email the MX record is what is referenced as to where the email should go, it also neglects to mention "round-robin" DNS or Anycast DNS which are used by to distribute the web and an important part of modern day internet usage.
> The PTR (or reverse) record query is used to validate that the IP address is assigned to the same host that is resolved in the Mail eXchanger (MX) record query
It does not explain that when you try to send an email the MX record is what is referenced as to where the email should go, it also neglects to mention "round-robin" DNS or Anycast DNS which are used by to distribute the web and an important part of modern day internet usage.