The general term for this is "Forward Confirmed reverse DNS" (FCrDNS). I do these checks (plus others) on my Postfix mail systems. I would assume most of the

The general term for this is "Forward Confirmed reverse DNS" (FCrDNS). I do these checks (plus others) on my Postfix mail systems. I would assume most of the other (sane) MTAs can perform these checks as well.