Check whether your domain's sending IP is listed on Spamhaus, SpamCop, Barracuda, SORBS and 6 other major DNSBLs — a listed IP can tank deliverability even with perfect SPF/DKIM/DMARC.
Free, no signup required. 10 checks/hour per IP.
Common questions
What is an email blacklist (DNSBL)?
A DNSBL (DNS-based Blackhole List) is a public database of IP addresses reported for spam, abuse, or malware. Mail servers check these lists in real time — if your sending IP is listed, receivers may reject or spam-folder your mail automatically, regardless of how good your content or authentication is.
What IP does this tool check?
We resolve your domain's A record first. If the domain itself has no A record (common for pure-sending domains), we fall back to the IP of its primary MX host. That's the IP actually responsible for sending or receiving your mail.
I'm listed — what do I do?
Each DNSBL operator has its own delisting process, usually free. Spamhaus (spamhaus.org/lookup), SpamCop (spamcop.net/bl.shtml) and the others linked in your results all run self-service removal request forms. Fix the underlying cause first (compromised server, open relay, spam campaign) or the listing often recurs within days.
Why would a shared ESP IP be listed?
If you send through a shared IP pool (common on lower-tier ESP plans), another sender on the same IP can get it blacklisted through no fault of yours. This is one of the strongest arguments for a dedicated sending IP once your volume justifies it — your deliverability stops being tied to a stranger's behavior.