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<\/div>\n \n Tired of flagged proxy IPs? An IP blacklist, also called a blocklist, DNSBL or RBL, is a database of IP addresses linked to spam, malware or abuse. Mail servers, firewalls and security tools check it before they accept traffic.<\/p>\n\n\n\n DNSBLs run on the DNS system. To check an IP, a server reverses its octets and adds the blacklist zone. For 203.0.113.7 checked against SpamCop, the query is 7.113.0.203.bl.spamcop.net. A listed IP returns an address like 127.0.0.2. An unlisted IP returns nothing. That is why the check is fast enough to run on every incoming email.<\/p>\n\n\n\n Listings come from spam traps, user reports and automated abuse detection. Each list has its own rules for adding and removing IPs. Some list single IPs, others whole ranges. A domain blacklist works the same way but lists domains found in spam links.<\/p>\n\n\n\n Public DNSBLs are only one layer. Gmail, Microsoft, Cloudflare and most anti-fraud platforms run private reputation systems. They score IPs on connection type, abuse history, proxy or VPN detection and behavior. You cannot look these lists up directly. An IP can pass every DNSBL check and still get blocked by a website. A full check therefore includes a reputation score, not only a blacklist scan.<\/p>\n\n\n\n Bounce messages are the most useful clue. They often name the blacklist that blocked you.<\/p>\n\n\n\n Blacklists track your public IP, not the local router address like 192.168.x.x. Open NodeMaven’s free IP Lookup<\/a>. It shows the public IPv4 or IPv6 address that websites see, plus its ISP, ASN and location.<\/p>\n\n\n\n For a mail server, check the IP that actually sends mail. You can find it in the \u201cReceived\u201d headers of an email you sent. If you use a proxy or VPN, confirm you are checking the IP that sites really see. A browser can expose a second address through WebRTC. Our guide on WebRTC leaks<\/a> explains how this happens.<\/p>\n\n\n\n Paste the IP into a checker that queries many lists at once. MXToolbox<\/a> checks it against more than 100 DNS blacklists. MultiRBL and DNSChecker give a quick second opinion. Each list shows OK or LISTED.<\/p>\n\n\n\n Spamhaus and Barracuda power filtering on a large share of mail servers. Check them directly on their own lookup pages. Those pages also explain why the IP was listed and how to remove it.<\/p>\n\n\n\n A clean DNSBL result does not mean a clean IP. Look at the threat score and detection flags in NodeMaven IP \u67e5\u8be2<\/a>. The tool flags proxy, VPN, Tor, hosting and mobile traffic. A high score or a hosting flag explains why sites challenge you with zero blacklist listings.<\/p>\n\n\n\n Most of these lists started as spam filters. That is why an email IP blacklist check and a general IP blacklist check return the same names. Firewalls and security tools then reuse the same data.<\/p>\n\n\n\n
Start your NodeMaven trial for $3.50 and get 750 MB<\/strong> of filtered residential and mobile proxy traffic<\/p>\n<\/div>\n <\/div>\n \n \u5173\u952e\u8981\u70b9<\/h2>\n\n\n\n
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What is an IP blacklist?<\/h2>\n\n\n\n
How DNS blacklists work<\/h3>\n\n\n\n
Public blacklists vs private reputation systems<\/h3>\n\n\n\n
Signs your IP might be blacklisted<\/h2>\n\n\n\n
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How to check if your IP is blacklisted: step by step<\/h2>\n\n\n\n
Step 1. Find your public IP<\/h3>\n\n\n\n
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<\/figure>\n\n\n\nStep 2. Run a multi-blacklist check<\/h3>\n\n\n\n
Step 3. Confirm on Spamhaus and Barracuda<\/h3>\n\n\n\n
Step 4. Check the threat score<\/h3>\n\n\n\n
Step 5. Read the results correctly<\/h3>\n\n\n\n
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Major IP blacklists and how to check each<\/h2>\n\n\n\n