I regularly use two different domains to send and receive mail in our organisation.
I found that some clients often did receive our emails so I configured reverse DNS with Example.com with our ISP. As soon as I did that the issue was resolved.
I wanted to setup reverse DNS on our other domain Example.edu.au but our ISP said that we can only setup reverse DNS on one domain.
As a result, we purchased addition IP addresses for our internet connection and configured reverse DNS on another IP address that we have been allocated..
My question is;
Do I need to change the MX record on Example.edu.au to point to the IP address that we configured reverse DNS on? Or doesn’t it matter as it is on the same internet connection?