Backscatterer is a less than reputable service displaying characteristics of a money making operation. Unlike other RBLs, they require payment should you want to be de-listed and before they will re-evaluate the IP address. They also do not offer any contact details.
From the research conducted by Mimecast, this has confirmed that the list should not be used (except perhaps as a Tag service)
DNSStuff.com lists Backscatterer.org as one of their 84 official block lists however DNSStuff state:
"Backscatterer is NOT a blacklist. Nobody should be blocking mail based solely on data from a backscatter list. The most any mail administrator should do is use it as part of a weighting or scoring system when determining whether to FLAG a message as POSSIBLE spam."
We would advise you to contact the Administrators of the receiving domain to make them aware of the above and to recommend they don't use the Backscatterer RBL as a block list.