Blacklist Checker
Check a domain and its mail-sending IP against 7 major spam and malware blocklists in one pass. A complimentary tool from Squish — no signup.
Try , ,
What a blacklist listing actually means
Blocklists (DNSBLs) are reputation databases that mail servers consult before accepting your email. IP lists track the address your mail is sent from; domain lists track the domain itself. A listing means that list recently saw spam, malware, or a compromised site associated with you — and receivers that trust the list will start refusing or junking your mail. The fix is always cause-first: clean up whatever earned the listing, then request delisting.
Common questions
Which blocklists does this check?
IP lists: Spamhaus ZEN, SORBS, SpamCop, and Barracuda — these track sending IP addresses. Domain lists: Spamhaus DBL, URIBL, and SURBL — these track the domain itself, usually because it appeared in spam or hosted something malicious.
I'm listed — what do I do?
First find out why: a compromised website, a mail account sending spam, or a shared IP with a bad neighbour are the usual causes. Fix the cause first — delisting without fixing it gets you relisted. Then each list has its own removal process (Spamhaus and Barracuda have lookup/removal pages; SpamCop listings expire on their own within about 24 hours of the spam stopping).
What does "no answer" mean?
That list didn't respond to our query just now, so we can't say either way — we count it neither clean nor listed. It's usually temporary rate-limiting on the list's side; re-run in a few minutes.
Does a listing always mean my email is blocked?
No — receivers weigh lists differently. A Spamhaus listing will block mail almost everywhere; a SORBS listing alone often changes little. But any listing is a symptom worth chasing down before it spreads to the lists that do hurt.
Bouncing email is usually an auth problem before it's a blacklist problem. Squish-managed email sets up SPF, DKIM, and DMARC properly and keeps them healthy — the single best way to stay off these lists.
Fix email with Squish →