Email blacklist check

Check an IP or domain against six major DNSBLs. Listing on any of these can hurt your inbox placement.

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About DNSBLs

DNS-based blocklists (DNSBLs) are zone files that mail servers query to decide whether to accept connections from a given IP. They're effectively shared reputation systems — if SpamCop, SORBS, or CBL has seen abuse from your IP recently, lots of mail providers will reject or spam-foldering your messages.

If you give us a domain, we resolve it to A records first, then check each IP. We check up to three A records to keep things fast.

About Spamhaus: Spamhaus blocks queries from public DoH resolvers (Cloudflare 1.1.1.1, Google 8.8.8.8) for their free tier — they want paying customers using their direct feed. We can't reliably check Spamhaus from this tool. To check Spamhaus, use their official lookup tool directly.