Blacklist Checker
Checks an IPv4 address against a curated set of well-known email blacklists (DNSBLs). Some large providers (e.g. Spamhaus) block automated queries from cloud services and are intentionally left out — this is a useful signal, not a complete picture.
Frequently asked questions
Why are some blacklists missing from this checker?
Spamhaus-operated lists (Zen, SBL, XBL, PBL) are intentionally left out. Spamhaus blocks automated lookups from cloud providers like the one this tool runs on, so including them would only ever return a false blocked result instead of a real one. The lists checked here give an honest answer.
Is this free to use?
Yes, completely free, with no signup or account required.
Do you store the IP addresses I check?
No. Each check is a live, one-time lookup — we don't save what you type in.