Free tool

IP Blacklist Checker

Check any domain against 10 major DNSBLs in parallel. We resolve your domain's IPs and query each list, full result in seconds.

What's in scope

We resolve your domain to A records, then query each blacklist against each IP. We weight Spamhaus heavily, a listing there is treated as critical because Gmail, Outlook, and Yahoo all consult it. Minor lists get warnings rather than failures unless 3+ lists agree.

What we don't check

Domain-level blacklists like Spamhaus DBL. Those use different mechanisms. We focus on IP-based DNSBLs, which are the ones that matter most for sending reputation.

Continuous monitoring

One-time checks are useful, but blacklist status changes hour to hour. Sign up for continuous monitoring and we'll re-run the same 10-list check every hour and alert the moment any of your IPs get listed, so you can request delisting within minutes of incident rather than days.

FAQ

Which blacklists do you check?
We query 10 of the most-influential DNSBLs in parallel: zen.spamhaus.org, b.barracudacentral.org, bl.spamcop.net, dnsbl.sorbs.net, spam.dnsbl.sorbs.net, cbl.abuseat.org, dnsbl-1.uceprotect.net, psbl.surriel.com, all.s5h.net, and blacklist.woody.ch.
Why does this take longer than other checks?
10 separate DNS lookups against 10 different servers, some of which are slower than others. We do them concurrently with a 5-second per-server timeout, so the whole check completes in under 10 seconds even when several lists are slow.
I'm listed but my mail is being delivered. Should I care?
It depends which list. Spamhaus listings will tank your deliverability fast, fix immediately. Listings on minor lists may have little real impact, but they're symptoms of underlying reputation issues that often escalate.
How do I get delisted?
Different lists have different processes. Spamhaus offers self-service removal at check.spamhaus.org for first listings. Barracuda has a removal request form. Most lists require you to identify and fix the underlying cause first. See our blacklist recovery guide for the full process.
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