Enter a URL
This list above is of 80 DNS-based antispam databases. (DNS stands for Domain Name System, not for Do Not Solicit.) Most Internet service providers (ISPs) and web servers look to these lists for IP addresses linked to computers that send out spam or unwanted action.
Your IP address could have resulted in the blacklisted symbol () appearing next to a few databases. It may be that for some reason your IP address was flagged at one point and blocked by some servers. (It might be that someone who was once put that IP address was blacklisted.)
Naturally, if it seems that you are involved in spamming or other unwanted on-line behavior, your IP address could get blacklisted and blocked. It will get land and flagged on at least one of those databases. You will manage to see that here at any time by running a new blacklist check.