IP Blacklist (RBL/DNSBL) Check
Check an IPv4 against major mail blacklists (Spamhaus, SpamCop, Barracuda, etc.).
About this tool
DNS-based blackhole lists (DNSBLs) are how the world flags compromised, abusive, or open-relay mail servers. We check seven well-known free RBLs in parallel and report any hits with the listing reason when available.
FAQ
- Why are some lookups inconsistent?
- Several RBLs rate-limit DNS queries from busy resolvers. If a zone errors, it does not mean the IP is clean — try again from a different network or via the operator's own lookup page.