Cox.net issues with their DNSBL

I'm not sure if this is the proper place to put this so I'll make this
short. Cox.net is showing errors when I'm sending mail indicating that we're
blocked by Invaluement, Cox error IPBL100. I've checked and my mx isn't
listed. Attempts to contact the postmaster@cox.net address result in an
autoresponder and then a bounce as that address is over quota. Is anyone
else seeing this problem?

Please feel free to contact me off list.

not sure about seeing the same problem, but I am at MAAWG and their postmaster/abuse team is here. need an intro?

-Dennis