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!