Email Blacklist Checker
Check if an IP address is listed on 25+ major email blacklists (DNSBLs). Paste any IP — your mail server, a sender, or an IP from your email headers.
Spamhaus PBL and ZEN are shown as policy — not spam blacklists. PBL lists IP ranges that shouldn't send email directly (DNS servers, CDN IPs, broadband). Normal for non-mail IPs.
Spamhaus blocks queries from public DNS resolvers (including Cloudflare DNS used here) after a threshold. Spamhaus results showing "limit" are not real listings — they are query-limit errors (return code 127.255.255.x). For authoritative Spamhaus results, use check.spamhaus.org directly.
// what are dnsbl blacklists?
DNSBL (DNS-based Blackhole List) blacklists are real-time databases of IP addresses known for sending spam or malicious email. Mail servers query these lists before accepting email — if your IP is listed, your mail may be rejected or sent to spam.
Being listed doesn't always mean you sent spam — dynamic IP pools, compromised servers, and shared hosting IPs frequently get listed. If you're listed on a major list like Spamhaus, request removal and ensure your mail server is properly secured.
The most important lists to be clean on: Spamhaus ZEN (most widely used), Barracuda, and SORBS.