Blacklist Check Tool
What Is a Blacklist Check?
A blacklist check detects whether an IP address appears on spam/email reputation blacklists. These lists track IPs known for sending spam, malware, or other malicious activity. Mail servers use these blacklists to block incoming email from suspicious sources. If your IP is blacklisted, legitimate emails may be rejected. Blacklist checks help you diagnose email delivery issues and verify your server's reputation.
Common Blacklists
Spamhaus Zen
The most widely used blacklist. Combines multiple Spamhaus lists for comprehensive spam detection.
The most widely used blacklist. Combines multiple Spamhaus lists for comprehensive spam detection.
Barracuda
Real-time reputation database maintained by Barracuda Networks for blocking malware and spam.
Real-time reputation database maintained by Barracuda Networks for blocking malware and spam.
Sorbs
Spam and Open Relay Blocking System, one of the oldest blacklists dating back to 1997.
Spam and Open Relay Blocking System, one of the oldest blacklists dating back to 1997.
URIBL
Identifies hosts that have hosted spam, malware, phishing, or other malicious content.
Identifies hosts that have hosted spam, malware, phishing, or other malicious content.
Trend Micro MAPS
Mail server blacklist tracking known spam sources and compromised systems.
Mail server blacklist tracking known spam sources and compromised systems.
Learn More About Email & IP Reputation
What Is an IP Address?
A plain-English guide to how IP addresses work, the difference between public and private IPs, and what yours reveals.
Can Someone Track Me With My IP?
Real risks vs. myths — what someone can and cannot actually do with your IP address.
How to Hide My IP Address
VPN, Tor, proxy, or mobile data — the four methods that work, with honest pros and cons.
What Can Hackers Do With Your IP?
DDoS, port scanning, and more — here's what's actually possible and how to protect yourself.
Why Does My IP Show the Wrong City?
IP geolocation is often off by 50+ miles. Here's the real reason and what you can do about it.