Free Tool
Email Blacklist Checker
Runs your domain or sending IP against 16 blacklists simultaneously. If you've picked up a listing - Spamhaus, SpamCop, Barracuda, wherever - you'll see it here with a direct link to request removal.
What a blacklist listing actually does to your email
A DNS blacklist is a real-time database of IP addresses flagged for spam. When your email hits a receiving server, that server often queries one or more of these lists before deciding what to do. Listed means rejected or junk. Clean means it passed that check.
What catches people off guard is how easy it is to end up listed without having done anything wrong yourself. Previous tenant of your IP had a bad history. Another customer on your shared hosting subnet got flagged. Your server briefly got hit by something and sent a few hundred spam messages before anyone noticed. One campaign had a complaint rate that caught SpamCop's attention. Not always your fault - but always your problem to deal with.
The sixteen lists this checks
Spamhaus is the one that actually matters most. Queried by almost every major provider. ZEN is the combined list: SBL covers IPs with direct links to spam operations, XBL covers hijacked machines and open proxies, PBL covers ranges that have no business sending email directly. One Spamhaus hit and you've got a serious deliverability problem on your hands. SpamCop runs on user reports - people submit spam, reports stack up, IP gets listed. Barracuda turns up in a lot of corporate email security setups, so a listing there blocks delivery to a big chunk of business inboxes. Then there's SORBS, UCEPROTECT, NiX Spam, SpamRats, WPBL, Mailspike and Unsubscore - smaller reach per list but collectively used across a lot of mail infrastructure.
- Spamhaus ZEN - combined SBL, XBL and PBL. Most widely used single list in the world.
- Spamhaus SBL / XBL / PBL - spam operations, exploited machines, and ranges that shouldn't send direct
- SpamCop - community-reported. Listings expire automatically if sending improves.
- Barracuda - heavy corporate use. Self-service removal form available.
- SORBS, UCEPROTECT L1/L2/L3, NiX Spam, SpamRats, WPBL, Mailspike, Unsubscore - smaller reach, still worth clearing
Getting off a list
Every listing in the results comes with a direct removal link. Spamhaus PBL is usually your ISP's job. SBL and XBL want to know what changed before they'll remove you. SpamCop auto-expires if complaint volume drops off. Barracuda has a form that typically processes within a day. UCEPROTECT L2 and L3 charge for fast removal, which is unpopular for good reason - most people either wait or get a new IP.
Don't put in a removal request before fixing the actual problem. You'll just get relisted.
How to stay off them
Genuine opt-ins only. Watch your complaint rates - if people are marking your emails as spam, that's the list talking. Get SPF, DKIM and DMARC right (the auth checker handles that). Dedicated sending IPs for any real volume. And run this check regularly rather than finding out when your bounce rate spikes.
Need to verify email addresses too?
The MailVerify API checks addresses in real time - valid, invalid, catch-all, disposable, role. ICO registered, GB servers, no list storage. First 25 searches free.