Free Email Blacklist Checker

An email blacklist checker tells you whether your sending domain or IP address has been flagged by the blocklists that mailbox providers consult before deciding where to put your mail. Enter a domain, email, or IP, and the tool checks it against 9 widely-used public DNSBLs (Spamhaus ZEN, SpamCop, Barracuda, SORBS, CBL/abuseat, PSBL, UCEPROTECT, and others) in parallel, then reports exactly which lists flag you and which come back clean.

Why being blacklisted matters for outbound: when you appear on a major blocklist, a large share of your cold emails get rejected or filtered to spam before anyone reads them, regardless of how good your copy or targeting is. Most senders don't find out until reply rates quietly collapse. A 10-second check tells you whether a blacklist is the hidden reason your campaigns stopped working.

How domains end up on blacklists: the number one cause for outbound teams is bounces. When you send to invalid or outdated addresses, those bounces and any spam-trap hits get reported, and blocklists flag your domain or IP. Other causes include sudden volume spikes, missing authentication (SPF/DKIM/DMARC), and shared IPs poisoned by other senders.

The pattern is almost always the same: a dirty list produces bounces, bounces produce a blacklisting, and a blacklisting kills deliverability.

That is the connection to keeping a clean list. The fastest way to stay off blocklists is to never send to addresses that will bounce in the first place. Cleanlist verifies every address on your list across 15+ providers at 98% accuracy before you send, catching the dead and risky addresses that would otherwise trigger a blacklisting.

Run this checker to see where you stand today; verify your list to stay clean tomorrow. While you're auditing your setup, the MX lookup tool confirms your mail and SPF records are configured correctly. Privacy note: this tool queries public DNS blocklists only. It does not send email or store the values you check.