IP Blacklist Checker
Check any IP address or domain against 50+ email blacklists and DNSBLs simultaneously. Find out if you're listed on Spamhaus, Barracuda, SORBS, SpamCop, and more.
What Is a DNSBL?
A DNS-based Blackhole List (DNSBL) is a real-time list of IP addresses known to send spam or engage in malicious activity, published via DNS. Email servers query these lists for every incoming connection to decide whether to accept, reject, or filter messages.
If your mail server's IP appears on Spamhaus or Barracuda, your emails will be rejected or filtered by major email providers including Gmail, Outlook, and Yahoo.
How to Get Delisted
- Spamhaus — spamhaus.org/lookup → request removal
- Barracuda — barracudacentral.org/rbl/removal-request
- SpamCop — spamcop.net → delist page
- SORBS — sorbs.net → delistings
- Fix the root cause first (spam, malware, open relay)
- Allow 24-48h after removal for propagation
Frequently Asked Questions
A DNSBL is a list of IP addresses known to send spam, published as DNS records. Email servers query these to decide whether to accept connections. Being listed means your emails may be blocked or filtered.
Common reasons: a compromised device on your network sent spam, your mail server is an open relay, a previous IP owner had issues, your IP was part of a botnet, or you sent bulk email without proper authentication.
Fix the root cause first — patch the vulnerability, clean infected systems, or tighten your mail server config. Then visit each blacklist's site to request manual removal. Spamhaus and Barracuda have self-service portals.
We query each blacklist directly via DNS in real time. Results are as accurate as each list's own data. Some lists may have occasional lookup failures. The most important ones to check are Spamhaus ZEN, Barracuda, and Spamcop.