Fake DNSBLs
Spamhaus recently announced a few years ago that they have discovered a company that is pirating various blocklists, relabeling them and selling access to them. Not only is the company distributing the zones, they’re also running a “pay to delist” scheme whereby senders are told if they pay money, they’ll be removed from the lists.
The fake company does remove the listing from the fake zones, but does nothing to remove the IP from the original sender. This company has been caught in the past and was blocked from downloading Spamhaus hosted zones in the past, but have apparently worked around the blocks and are continuing to pirate the zone data.
It’s not clear how many customers the blocklist has, although one ESP rep told me they were seeing bounces referencing nszones.com at some typo domains.
No legitimate DNSBL charges for delisting. While I, and other people, do consult for senders listed on the major blocklists, this is not a pay for removal. What I do is act as a mediator and translator, helping senders understand what they need to do to get delisted and communicating that back to the blocklist. I work with senders to identify good, clean addresses, bad address segments and then suggest appropriate ways to comply with the blocklist requirements.