Blacklist check

Check if an IP is on known blacklists (DNSBL)

What is a blacklist check? Mail servers and spam filters maintain shared lists (DNSBL) of IP addresses known for sending spam or malicious traffic. If an IP ends up on one of these lists, emails from it get blocked or flagged. This tool checks an IP against several major blacklists so you can spot problems before they affect deliverability.
Enter an IP address above to get started.

Which lists are checked

The IP is checked against widely used DNS blacklists, including Spamhaus ZEN (SBL, XBL and PBL), SpamCop, Barracuda, PSBL, DroneBL, UCEPROTECT and others. Lists that can’t be queried at the moment show as Unavailable rather than clean.

Listed — what now?

  1. Find the cause: a compromised mailbox sending spam, an infected computer, an open relay, or a website form abused to send mail. Delisting without fixing it only lasts a few days.
  2. Fix it: reset the affected password and turn on MFA, remove the malware, close the relay or protect the form.
  3. Request removal on each list’s website. Some, like SpamCop, expire on their own once the spam stops.

Not every listing is equal

Spamhaus is used by most large mail providers, so a listing there matters most. A Spamhaus PBL listing on a home or dynamic IP is normal and not a penalty — it just means that address shouldn’t send mail directly; send through your provider’s mail server instead. UCEPROTECT levels 2 and 3 list whole provider networks, so a listing there often isn’t caused by you, and few large providers rely on them.

To check a whole domain — mail servers, SPF, DKIM and DMARC — run the Domain trust report.