Blacklist checker
Check an IPv4 address against public DNS blocklists in one step. Private and reserved addresses cannot be listed, so they are not checked.
Frequently asked questions
- What is a DNS blocklist?
- A DNS blocklist (DNSBL) is a list of IP addresses that an organisation has identified as sending spam or other abuse. Mail servers and firewalls query it through DNS to decide whether to accept traffic.
- What does 'listed' mean?
- The list has an entry for that address. It is a signal, not proof of wrongdoing: addresses are often shared, and a listing can be left over from a previous user. Each list explains its own reason codes and removal process, which the Details link opens.
- Why does a list show 'Query refused'?
- Some lists refuse queries from shared public resolvers. The check is run for the listing itself, so the result is marked as not checked rather than as clean.
- How do I get my IP removed from a blocklist?
- Each list has its own removal process, linked from its Details entry. If the address is listed by one of our own reports, you can also request removal on this site.