The Unsubscribe Blacklist (UBL) is a real-time blacklist of IP addresses which are sending email to names harvested from suppression files. IP addresses listed on this service is being continually monitored and the list is updated hourly.
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 ubl.unsubscore.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.