Would you believe that I was able to get 100% same information what you gave in your reply.
You didnt tell technically watch behind those IP addresses.
User was asking adding to mx records. It only means that you have two mx records. Ok, you also have two IP:s. But in matter of fact, those both IP addresses could point to same server machine and even same server instance.
Or there could be very simply tcp/ip connection forwarding service on another server. If primary goal is simply to get two MX records with different IPs.
Any comments about that?