Network

IP Blacklist Checker

DNSBL Check

Check IP reputation

Enter an IP address or domain name to check against popular or comprehensive blacklist databases — a quick popular check or a thorough comprehensive scan.
Check Mode

Tool features

Comprehensive IP blacklist checking with detailed reputation analysis
4 checks

Popular Blacklist Check

Quick scan against a curated set of trusted IP blacklists (15 providers) for fast results

Comprehensive Check

Thorough scan against a wider set of live IP blacklists (41 providers) for complete analysis

Fast & Accurate

Real-time DNS queries with response time tracking and detailed reporting

Domain Support

Check both IP addresses and domain names with automatic IP resolution

What is a DNS blacklist & how it works

How DNSBLs affect your email deliverability

A DNS blacklist (DNSBL), also called a blocklist or RBL, is a published list of IP addresses and domains known for sending spam or hosting malicious content. Mail servers and security filters query these lists in real time — if your sending IP appears on one, your email can be rejected or dumped into spam before it ever reaches an inbox.

This checker queries your IP or domain against dozens of popular and comprehensive blacklists at once and shows exactly which ones list you. A single listing on a major blacklist like Spamhaus can devastate deliverability, so catching it early — and requesting delisting after you fix the root cause — is essential for anyone who sends email.

DNSBL / RBL
A DNS-based blacklist that mail servers query to decide whether to accept mail from a given IP.
Listing
An entry recording that your IP or domain is flagged. Each blacklist has its own criteria and delisting process.
Delisting
The process of requesting removal after you've stopped the spam or abuse that caused the listing.

How to use this tool

Check your IP or domain against blacklists in four steps
1
Enter an IP or domain
Type your sending IP address (e.g. 8.8.8.8) or domain name to check.
2
Choose a scan mode
Popular runs a quick check against major lists; comprehensive scans dozens of blacklists.
3
Run the check
We query each blacklist in real time and report which ones list your target.
4
Fix and request delisting
Stop the source of the abuse, then follow each blacklist's delisting process to be removed.

Related tools

Keep debugging with tools from the same suite
3 tools
IP Location
Find geographical location, ISP, organization, and detailed information for any IP address
PTR Lookup
Perform reverse DNS lookup to find hostname from IP address (PTR records)
Email Health Checker
Comprehensive email deliverability check including SPF, DKIM, DMARC, and MX records

Frequently asked questions

Common questions about blacklists and delisting
5 Q&A

Common causes include a compromised machine or account sending spam, an open mail relay, a shared hosting neighbour's abuse, or a formerly-abused IP you were assigned. Identify and fix the cause before requesting delisting.

First stop the underlying problem. Then visit the specific blacklist's website and submit a delisting request. Removing yourself before fixing the cause usually results in a fast re-listing.

Popular mode checks the major, high-impact blacklists quickly. Comprehensive mode queries dozens of additional lists for a thorough audit, at the cost of a slightly longer scan.

Primarily it affects email deliverability, but some blacklists are used by web reputation and security filters, so a listing can also trigger warnings for site visitors.

Check both. IP-based DNSBLs catch your sending server, while domain-based lists (like URIBLs) flag the domains that appear in message bodies.