RBL.JP stands for Realtime Blackhole List Japan and is the domain name the server designated for this service.
RBL.JP is coordinated by Hart Computer Co. Ltd. as a volunteer group project staffed by technologists from across Japan. Our goal is to create a system that is more user friendly for Japanese than existing similar systems. Additionally we also plan to make this system such that it can be used by those outside Japan as well.
RBL.JP is a system that allows anyone, free of charge, to search for the addresses of servers known to send spam. Most Spam is usually sent by third parties from servers from which they are able to access. If we can block the mail traffic coming from these servers, we can effictively reduce the amount of spam. RBL.JP stores a great number of these addresses and respond to requests in real time. To use these functions requires only slight modifications to your server's configuration.
RBL.JP contains not only information about servers that are used by unauthorized third parties to send spam, but also servers that are known to distribute malicious spam. Use of this system allows you choose all or some of the funcitonality and thus you can determine the level of mail blocking to be used.