This is a free to use list that uses custom Honey Pots/Spam Traps, harvesting detection systems, and other mechanisms for detecting spam and harvesting attacks to determine IP addresses that are spamming. IP addresses get removed after three days but a delisting can be requested by emailing them.
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 service.mailblacklist.com. 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.