Is Your Server on a Blacklist?
A blacklisted IP means bounced emails and blocked traffic. Check your server against major blacklists in seconds, for free.
Check an IP or domain
Check a target against six major DNS blacklists and see any delisting guidance.
Blacklisting rarely announces itself
You usually find out your mail server is blacklisted when a client says "your emails are going to spam" — after it's already cost you deliverability for days or weeks. This tool checks your IP or domain against the major DNS-based blacklists right now, and continuous monitoring can catch it the moment it happens.
1. Enter the IP address or domain you want to check.
2. CloudStats queries major DNSBL (DNS-based blacklist) providers in real time.
3. See which lists, if any, currently flag your IP or domain.
4. Set up continuous monitoring to get alerted the moment a new listing appears.
FAQ
Frequently asked questions
What is a blacklist checker actually checking?
It queries DNS-based blacklists (DNSBLs) — databases of IP addresses and domains flagged for spam or abuse — and reports which ones currently list your target.
How often should I check if I run a mail server?
Continuously, ideally. A single manual check only tells you the status at that moment; a new listing can appear at any time.
What should I do if I'm blacklisted?
Identify and stop the cause (compromised account, misconfigured mail relay, malware), then follow the specific blacklist provider's delisting process.