IP Blacklist Check
Check whether an IP address appears on 8 major DNS-based spam and email blacklists (DNSBLs). Results are fetched live via Google Public DNS.
Enter the IP address you want to check, or click “Use My IP” to fill in your current public address.
IP Blacklist Check
What Are DNS Blacklists?
DNS-based Blackhole Lists (DNSBLs), also called Real-time Blacklists (RBLs), are databases of abusive IP addresses. They flag addresses known to send spam, host malware, run open proxies, or behave abusively in other ways. Mail servers and spam filters consult these lists in real time before accepting or delivering email. If your IP appears on a major list, your outbound email may be blocked, sent to spam, or flagged. That can happen even when a previous owner caused the abuse. It can also happen when a compromised device on your network did. Understanding how DNS works explains how these lookups happen almost instantly on every incoming connection.
How DNSBL Checking Works
Each DNSBL check uses a simple DNS query. To test an IP, the octets are reversed and prepended to the DNSBL zone. Checking 1.2.3.4 against zen.spamhaus.org means querying the A record for 4.3.2.1.zen.spamhaus.org. If a DNS answer comes back, the IP is listed. If the query returns NXDOMAIN, the IP is clean on that list. A listed result usually returns a 127.0.0.x code that tells you which dataset matched. This tool runs all 8 checks at once, reports every result, and shows the return code where one is present.
Why Do IPs Get Blacklisted?
An IP commonly lands on a blacklist for several reasons. Those include sending spam or phishing email, running an open mail relay or open proxy, and hosting botnet command-and-control infrastructure. Being assigned from a dynamic residential range with an abuse history is another. Often the current owner is not at fault. The address may have been reassigned from a previous user, or a device on the network may have been compromised. Dynamic residential IPs frequently appear on policy lists like UCEProtect regardless of actual sending behavior.
What To Do If Your IP Is Listed
If this tool shows your IP listed, the next steps depend on which lists are involved. For Spamhaus and SpamCop, use their self-service lookup and delisting pages. You will need to explain what caused the listing and confirm it is resolved. For Barracuda, submit a removal request through their reputation portal. Many lists remove an IP automatically after a clean period, typically 7 to 30 days. If the underlying issue is fixed, you may simply need to wait. If you use the listed IP for outbound email, contact your ISP or mail provider. They can often speed up delisting. A reverse DNS lookup helps confirm which organization controls the IP — see also our guide on what reverse DNS is and why it matters. Checking your domain’s authentication records with the Email Auth Checker also helps. Solid SPF and DMARC records lower the risk of future listings.
How to Prevent Being Listed
The best protection is a clean, well-configured mail environment. Publish valid SPF, DKIM, and DMARC records for every sending domain. Run an SPF record lookup to verify your policy is correct before you start sending. Keep software and mail server configurations patched and current. Avoid sending to purchased or scraped email lists. High bounce rates and spam complaints are among the fastest routes to a listing. If your IP is shared, as with many cloud hosts, monitor it regularly. Some providers offer dedicated IP addresses for mail, which gives you a clean reputation baseline under your own control. You can investigate DNS records for any domain with our DNS Lookup tool. Browse every diagnostic from the network tools hub.
A Note on Spamhaus Access
From April 2026, Spamhaus began enforcing its fair-use policy more strictly. It blocks public DNSBL queries that originate from certain high-volume hosting providers. This tool routes its lookups through Google Public DNS, so the checks here are unaffected. If you run your own mail server on a flagged host, though, your server’s direct Spamhaus queries may be refused. In that case, Spamhaus directs operators to its free Data Query Service.
Frequently Asked Questions
What does it mean if my IP is on a blacklist?
It means a DNSBL operator flagged that IP for spam, malware, an open relay, or policy reasons. Mail servers that check the list may block, defer, or junk email from it. The current owner is not always at fault, since addresses get reassigned and devices get compromised.
How do I get my IP removed from a blacklist?
First fix the cause, such as a compromised device or a misconfigured mail server. Then use the operator’s self-service delisting page. Many lists also remove an IP automatically after a clean period of 7 to 30 days. Repeated requests without a fix can make a listing permanent.
Why does one blacklist list my IP when others say it is clean?
Each list has its own criteria and data sources. Some target confirmed spam, others list entire dynamic or residential ranges by policy. A residential IP can sit on a policy list like UCEProtect while staying clean on spam-trap lists like Spamhaus. Listing on one list does not imply listing on all.