How to use spamcop API in Geek/Tech Things Posted August 15, 2014 · Edited August 15, 2014 by prabhjot Hello all, I am new to SpamCop. I read on this page http://www.spamcop.net/fom-serve/cache/351.html that we can use a dns query to know if an IP is in a black list or not in our custom application/software. The page says that if I want to check an IP like 22.214.171.124 then my dns query should be: nslookup 126.96.36.199.bl.spamcop.net But for me this returns the messsage that this is a non-existent domain. I wanted to confirm my understanding. So, if I receive non-existent domain message it means that IP is not blacklisted else it is blacklisted? Thanks and have a nice day!