Comprehensive Blacklist Lookup
Instantly check your IP or Domain against dozens of major spam blacklists (DNSBLs).
What is a Blacklist Lookup?
A blacklist lookup tool checks if an IP address is on a DNS-based Blackhole List (DNSBL). These lists are used by email providers to identify and block mail from IPs known for sending spam.
If your server's IP is on a blacklist, your emails may be rejected. This tool helps you diagnose email deliverability issues by checking your IP against dozens of reputable blacklists.
Key Features
Comprehensive Check
Scans your IP address against dozens of the most reputable DNSBL spam blacklists from around the world.
Real-Time Results
Each check is performed live, giving you the most current and accurate status for your IP reputation.
Domain & IP Input
Enter either a domain name (which we resolve to an IP) or an IP address directly for maximum flexibility.
Live Status Updates
Watch the results table populate in real-time as each blacklist server is checked, complete with a progress summary.
Clear Status Indicators
Instantly see if you are "Listed" (bad) or "OK" (good) with clear, color-coded results for each blacklist.
Export to CSV
Download the complete report as a CSV file for your records or to share with your team or hosting provider.
Blacklist Checker
How to Use
Enter IP or Domain
Input the domain or IP address of the mail server you want to check.
Start the Check
Click the "Check Blacklist" button to begin the live scan against our database of servers.
Review the Results
Watch as the table updates in real-time. Look for any "Listed" statuses in red.
Take Action
If your IP is listed, follow the steps in the section below to resolve the issue and request delisting.
Understanding Your Results
What is a SPAM Database Server?
Each item in the list (like Spamhaus ZEN or Barracuda RBL) is a DNSBL, or a real-time blacklist of IP addresses. Email servers all over the world check these lists to help them decide whether to accept or reject an incoming email. Being on even one of these lists can cause your emails to be blocked.
Status: OK
This is the best possible result. It means the specific SPAM database does not have your IP address on its list. Your IP reputation is clean with this provider.
Status: Listed
This is a bad result. It means your IP address is on that specific blacklist and your emails are likely being blocked by servers that use this list. **What to do:**
- **Identify the Cause:** First, you must find out why you were listed. Common reasons include a compromised user account sending spam, a misconfigured server, or being on a shared IP with a bad actor. Check your server logs for unusual activity.
- **Fix the Problem:** Secure your server, remove the malware, or close the security hole that led to the spam being sent.
- **Request Delisting:** Visit the website of the specific DNSBL that listed you (e.g., go to `spamhaus.org`). They will have a lookup tool and a procedure for you to request removal from their list. You must have fixed the underlying problem before they will delist you.
Use Cases
Email Deliverability Troubleshooting
If your users or customers report that your emails are not arriving or are going to spam, this is the first tool you should use. It will instantly tell you if your mail server's IP has a bad reputation.
New Server & IP Auditing
Before you start sending email from a new server or IP address, you must check if it is already on a blacklist. Sometimes, hosting providers re-assign IPs that were previously used for spam, and you need to get it delisted before you begin.
Protect Your Email Deliverability
Enter your domain or IP in the checker above to get your free, comprehensive blacklist report!
Check Your IP NowFrequently Asked Questions
What is a DNSBL?
DNSBL stands for DNS-based Blackhole List. It's a list of IP addresses known for sending spam. Email servers check these lists to decide whether to accept, reject, or flag an incoming email.
Is this tool free to use?
Yes, absolutely. Our Blacklist Lookup tool is 100% free and you can perform as many checks as you need.
Is my data private?
Yes. The tool performs DNS lookups which are public queries. We do not store or log the IP addresses or domains that you check.
My IP is not on any list, but my emails still go to spam. Why?
Being on a public blacklist is just one of many reasons for poor deliverability. Other critical factors include having correct SPF, DKIM, and DMARC records for your domain, the content of your emails, and your sender reputation with individual providers like Gmail and Outlook.
What should I do if my IP is listed?
If you are listed, first resolve the issue causing the spam (e.g., secure a hacked account). Then, visit the website of the specific DNSBL that has listed you and follow their delisting procedure.
Trusted by Thousands for 100+ Free Online Tools
Join a growing community of creators, developers, and businesses who rely on our all-in-one tools platform for secure, fast, and free online tools. Your trust is our top priority—no sign-ups, no hidden costs, and complete privacy.
Conclusion
Our Free Blacklist Lookup tool is an essential utility for anyone who relies on email. By providing a fast and comprehensive scan against dozens of the world's most important DNSBLs, it gives you immediate insight into your IP reputation. Use this tool to proactively monitor your servers and diagnose deliverability issues, ensuring your important messages reach their destination.
Have Questions or Need a Custom Tool?
Our team is here to help. Whether you have feedback on our tools or need a custom solution for your business, we'd love to hear from you.
Get in touch with us for support, suggestions, or partnership inquiries.
Contact Us