IP Blacklist Check
Check if your IP address is blacklisted in major RBL databases.
IP Blacklist Check — Scan 100+ RBL & DNSBL Databases
IP blacklist check queries 100+ Real-time Blackhole Lists including Spamhaus, Barracuda, SpamCop, and SORBS to determine if an IP address is listed and affecting email deliverability.
When your IP is listed on a blacklist, emails from that IP get rejected or sent to spam. Our tool scans 100+ RBL/DNSBL providers in parallel, grouped by tier: Core (Spamhaus, Barracuda — highest weight), Extended (regional providers), and Unreliable (noisy lists with high false-positive rates). Results include risk score, false-positive detection, and delist links.
What is an IP Blacklist (RBL/DNSBL)?
An IP blacklist is a DNS-based database of IP addresses known to send spam, host malware, or engage in abusive activity. Mail servers query these lists to decide whether to accept email from a sending IP.
When a mail server receives an SMTP connection, it queries the DNSBL by reversing the connecting IP and appending the list domain. If the DNS query returns a result, the IP is listed and the email may be rejected. Spamhaus ZEN is the most widely used, covering SBL, XBL, and PBL lists combined.
Spamhaus, Barracuda, SpamCop: Major Blacklist Providers
Spamhaus is the most impactful blacklist globally. A Spamhaus SBL or XBL listing causes rejection by Gmail, Microsoft 365, and Yahoo. Barracuda, SpamCop, and SORBS have significant but smaller impact.
Spamhaus ZEN combines SBL (direct spam sources), XBL (exploited systems), PBL (dynamic/residential IPs), and CSS (snowshoe spam). Barracuda and SORBS have their own categorization systems. Our tool checks all tiers and provides specific delist links for each listing.
How to Delist Your IP from Blacklists
Delisting requires: (1) identifying and fixing the root cause (spam, malware, misconfiguration), (2) submitting a delisting request through the provider's portal, (3) waiting for the listing to expire or be manually removed.
Each blacklist has its own delisting process. Spamhaus has a self-service portal and requires explaining the source of spam or abuse. Barracuda's listing expires automatically after 30 days if spam stops. SpamCop delists automatically once reports stop. For PBL listings (dynamic IPs), configure your server to use a relay rather than sending directly on port 25.
Scan any IP against 100+ DNSBL/RBL databases instantly and check your email sending reputation.
Check IP blacklist status nowUse Cases
Mail server operators check sending IPs regularly to catch blacklist listings before they cause delivery failures. Cloud hosting providers monitor IPs in their ranges for abuse. Email deliverability engineers diagnose why emails from a specific IP are being rejected. IT security teams check IPs associated with outbound email flows as part of regular infrastructure audits.