BL-Monitor is based upon a timing engine that simultaneously queries and measures multiple DNSBL response time. It also keeps track of how many queries on IP addresses are listed, unlisted or timed out without ever getting any response.

Based these factors, BL-Monitor ranks each DNSBL server. This rank lets you choose the DNSBL servers that are most effective for your site. Since ranking is based upon your mail traffic and is performed at your Internet location relative to the DNSBL servers, results are only significant for you.

BL-Monitor is supplied with an initial set of DNSBL servers and blacklisted IP addresses recorded by CMS. Analysis can start with just this supplied data but it will not reflect your mail traffic.
BL-Monitor is a useful email utility that will come in handy.

CMS recommends that IP addresses from your own mail traffic, representing both good and spam messages, are used. These IP addresses can be extracted from the anti-spam filtering product used at your site. Note that extracting only the blacklisted IP address for BL-Monitor analysis will cause the results to favor the DNSBL servers already being used.