Check if your IP address or domain is listed on spam blacklists and DNSBL databases
This tool queries public DNSBL (DNS-based Blackhole List) servers for informational and educational purposes only.
Blacklist Providers Used: Spamhaus, SORBS, SpamCop, Barracuda, URIBL, SURBL, CBL, and others. Please respect their terms of service.
DNS-based Blackhole Lists (DNSBLs), also known as Real-time Blackhole Lists (RBLs), are spam-blocking databases that list IP addresses and domains known for sending spam, hosting malware, or engaging in other malicious activities. Email servers worldwide use these lists to filter incoming mail and protect users from unwanted messages.
A blacklist is a database of IP addresses or domains that have been flagged for sending spam, hosting malware, running open relays, or other abusive behavior. When your IP or domain appears on one or more blacklists, email providers may:
Regular blacklist monitoring is crucial for:
Spamhaus: One of the most influential anti-spam organizations. Free for personal/small business use with reasonable query volumes. Usage Terms
SORBS: Spam and Open Relay Blocking System. Free for non-commercial use. Usage Terms
SpamCop: Automatically processes spam reports. Free for reasonable use. More Info
SURBL/URIBL: Focus on domain-based blacklisting. Free for low volume. Usage Policy
Barracuda: Commercial spam filtering service. Free for personal use. How to Use
If you find yourself on a blacklist:
Check against major blacklists including Spamhaus, SORBS, and more
Instant results from live DNS queries to blacklist servers
Check both IP addresses and domain names for blacklisting
A blacklist checker (also called DNSBL or RBL checker) is a tool that tests if an IP address or domain is listed on spam databases. Email providers use these blacklists to filter spam and malicious content. Being blacklisted severely impacts email deliverability - your emails may be rejected or sent to spam folders. Our tool checks your IP or domain against 15+ major blacklists instantly.
Yes! This tool is free for personal and small business use. We've implemented rate limits (50 checks/day, 1 check per 3 seconds) to comply with blacklist providers' fair use policies. These limits ensure the service remains free and available for everyone. If you need higher volume checking (>300k queries/day), you should contact blacklist providers directly for commercial licensing.
Enter your IP address in the checker above and click "Check Blacklists". We'll test against 15+ major blacklists including Spamhaus ZEN, SORBS, SpamCop, Barracuda, CBL, and more. Results show which lists you're on (if any) and which lists you're clean on. You can also click "Use My IP Address" to automatically check your current IP. Regular monitoring helps maintain good email deliverability.
If your IP is blacklisted: (1) Emails you send may be rejected completely, (2) Your emails may be marked as spam automatically, (3) Email deliverability drops significantly, (4) Recipients may never see your messages, (5) Your domain reputation suffers. You must identify the cause (spam, compromised server, open relay), fix the issue, then request removal from each blacklist. Each blacklist has its own delisting process and timeline.
Rate limits (50 checks/day, 1 check per 3 seconds) are implemented to: (1) Comply with blacklist providers' terms of service and fair use policies, (2) Prevent abuse of free DNSBL services, (3) Ensure the tool remains available for all users, (4) Respect the resources of volunteer-run blacklist services. Most providers require licensing for high-volume commercial use. Our limits are generous for personal/small business checking needs.
We check 15+ major blacklists including: Spamhaus (ZEN, SBL, XBL, PBL, DBL), SORBS (main, spam), SpamCop, Barracuda, CBL, PSBL, URIBL, SURBL, DroneBL, UCEPROTECT, and others. These are the most influential lists used by email providers worldwide. Each has its own criteria and delisting process.
Results are real-time queries directly to each blacklist's DNS servers, so they're as accurate as the blacklists themselves. However: (1) Blacklist data can change rapidly, (2) Different lists have different criteria, (3) Some listings auto-expire, others require manual removal, (4) A single check is a snapshot in time. We recommend checking regularly and from multiple locations if suspicious. Always verify critical results on the blacklist provider's official website.
Yes! Domain blacklists (like Spamhaus DBL, SURBL, URIBL) track domains appearing in spam messages. If your domain is blacklisted: emails containing links to your domain may be filtered as spam, even if sent from clean IPs. Domain blacklisting often results from: domain being used in phishing campaigns, appearing in spam messages, hosting malware, being newly registered and immediately used for spam. Domain reputation is separate from IP reputation.
If you need: (1) More than 300,000 queries per day, (2) Commercial reselling of blacklist data, (3) Integration into paid services, (4) Guaranteed SLA/uptime, then you should contact blacklist providers directly for commercial licenses. Major providers offer paid tiers: Spamhaus DQS, SURBL Commercial, URIBL Datafeed. This ensures continued support for volunteer-run services while meeting your business needs.