IP Blacklist Checker
Check whether an IPv4 address is listed on 25+ major spam and abuse blacklists (RBL/DNSBL) — including Spamhaus, Barracuda and SpamCop.
Why blacklist status matters
DNS blacklists (DNSBLs) track IP addresses associated with spam, malware or abuse. Mail servers query these lists to decide whether to accept messages, so an IP on a major blacklist can have its email silently rejected. If your mail server's IP is listed, identify the cause, fix it, then request delisting from each provider.