I use a spam filter called MX Logic that sits outside of my domain, and therefore send and receive mail from different servers. Because of this, I have PTR records setup for my outgoing mail servers to point back to my domain. Currently, if I go to mxtoolbox.com and type in my domain name, I green lights for everything (including the Reverse DNS Check). Last week though, the Reverse DNS Check was failing, and emails to cfl.rr.com (RoadRunner in Orlando) were getting stuck in the queue.
The thing is, nothing has changed in my Exchange configuration or at my ISP (as far as I know). This happens from time to time. What would cas a Reverse DNS check to intermittently fail?
I have attached my current test from mxtoolbox that shows all green lights.