The blacklist lists any third-party blacklists for the IP. Blacklists are monitored on an hourly basis. When a client IP is listed on a major blacklist like Spamhaus, we will actively reach out to the client to discuss delisting options.
All major blacklists are monitored. The total number monitored is currently more than 60, and new blacklists are added or updated as they become widely used.
Only active blacklists are listed. If this report doesn't currently show any data, then the IP is currently not listed on any major blacklists. All blacklists are monitored on any hourly basis; however, this report is generated daily at 12 a.m. GMT.