Blacklist Checker
Check if your domain or IP address is listed on any major email blacklist. Scan against Spamhaus, Barracuda, SORBS, and more.
Enter an IP address to check against major blacklists.
Get started freeWhat are email blacklists?
Email blacklists (DNSBLs — DNS-based Block Lists) are real-time databases of IP addresses and domains known to send spam or malicious email. Major email providers like Gmail, Outlook, and Yahoo check these lists when deciding whether to deliver, spam, or reject an incoming email.
Being on a blacklist means your emails may be silently rejected before they even reach your recipient's inbox. The worst part? You often don't find out until customers complain they aren't receiving your emails.
Common causes of blacklisting
Compromised account sending spam
An employee's email credentials were phished. The attacker sent thousands of spam emails from your domain before anyone noticed. Your IP is now on multiple blacklists.
Shared hosting IP tainted by others
Your sending IP was blacklisted 5 days ago because another tenant on your shared server sent spam. Your legitimate emails have been bouncing ever since.
Frequently asked questions
A real-time database (DNSBL) of IPs and domains known to send spam. Mail servers check these lists to decide whether to accept, spam, or reject incoming email.
Common causes: compromised accounts sending spam, shared hosting IP tainted by others, high bounce rates, or being reported for unsolicited email.
Fix the root cause first (compromised account, open relay). Then request delisting from each blacklist. Some auto-delist after the issue stops. Each list has its own process.
It varies. Some lists auto-delist within 24-48 hours. Others require manual review. Spamhaus and Barracuda typically process requests within a few days.
Daily blacklist monitoring
Know the moment you're listed, not when customers complain. Daily scans across 50+ blacklists.