I have a secondary MX that spammers are using to target my domain.
However, both my host and my secondary MX host are on residential DSL spaces, and our reverse DNS is not congruent with our forward DNS. (I think this is the root cause, but please read on)
MOST of the spam reports I process with SpamCop are finding the original sender, as well as the valid secondary MX, and testing them as possible spammers.
When analyzing the secondary MX, SpamCop properly identifies this host as a valid MX for the destination domain, and moves on to the next host.
When it looks at the original sender, it does the analysis for the reverse DNS of the secondary MX host IP. It finds that the IP is not a valid MX for this DNS domain. SpamCop identifies this examination as a forgery, and stops processing the analysis for the real spammer or open relay.
Can SpamCop be adjusted to exclude a host it finds as a valid MX for the final destination?
Here is a sample: