JustSpam.org lists IP addresses that they have not received any legit email from and is already listed by one of the other RBLs.
To get removed, the IP should first be removed from other lists then it can be removed from the website. But if the removed IP is seen SPAMming again it will be listed for 30 more days. To get removed you must send an email to a specific address with a specific subject generated by the lists website from the IP you are trying to remove.
IP XXX.XXX.XXX.XXX is sending justspam.org. More Information available at http://www.justspam.org/check/?ip=XXX.XXX.XXX.XXX
Is the information on our site wrong or incomplete? You don't want us to monitor your blacklist? Or do you operate a similar blacklist? We would like to hear from you!
We keep some statistics on blacklists. Below is the graph for dnsbl.justspam.org. We test blacklists by asking them to respond to known IP's that are blacklisted and known IP's that can't be blacklisted. Not every blacklist has such IP's, we test them with what is possible. We keep if we get any response or error messages and the response duration. Lower response times are better. These statistics may be useful for email server administrators to pick which blacklist to use.