Check whether your IP is on the blocklists mail servers use to filter spam. Leave the field blank to test your own address.
A DNS blocklist (DNSBL, also called an RBL) is a list of IP addresses that mail servers consult before accepting email. If your IP appears on one, your messages may be rejected outright or filtered to spam. This tool checks your IP — or any you paste — against the major lists mail servers actually use, including Spamhaus, SpamCop, and Barracuda, in a single pass.
Home users land on these lists when malware on the network sends spam, when an open relay or compromised account is abused, or when a dynamic IP is reused from a previous abuser. Servers get listed for sending unsolicited mail, poor configuration, or a damaged reputation inherited from a shared address. The cause determines the fix — you can’t clear a listing without first addressing why it happened.
Blocklists rate-limit lookups from shared resolvers, so a “clean” result here is indicative rather than an absolute guarantee — a list that didn’t respond is reported as clean. If your email still fails despite a clean check, the problem may be a list that didn’t answer, or authentication (SPF, DKIM, DMARC, reverse DNS) rather than reputation. Most lists offer a self-service delisting form once the underlying issue is resolved.
Learn more: How to check and fix a blacklisting · Remove your IP from Spamhaus · IP reputation on shared hosting