Security
Scan an IP across 60 DNSBL / RBL lists.
DNSBLs list IPs used for spam, botnets and abuse. If your mail server is listed, messages get rejected.
The query asks for an A record at reversed-IP + list zone. Hits on many lists are serious; a single list can be a false positive.
A shared hosting IP can be listed because of a neighbour. On a VPS, open proxies or a compromised CMS are common. Read logs before you delist.
Use each list’s delist form. First close open relays and malware on the mail host.
The checker queries 60 DNSBLs: Spamhaus ZEN, 0SPAM, Barracuda, SpamCop, UCEPROTECT and the other RBLs on the tool list.
If the A-record IP is listed, some corporate filters block the site too. Change IP or delist with the host.
Some lists support IPv6. Unsupported ones are skipped.
Your own IP and hosts you operate, yes. Do not profile other people’s IPs without a basis.