Free tool
Email blacklist check
Enter a domain or an IP. We check it against the email blocklists, find your domain's own sending servers and check those too, and tell you which listings matter.
Sending outreach from this domain? GEOboom finds the pages AI answers cite and runs the outreach to get you mentioned on them, with the mailboxes included.
See how it worksHow email blocklists work
Spam gets noticed
Lists run spam traps, addresses nobody would mail on purpose, and collect reports. A server or domain that hits them gets listed.
Published in DNS
Each list answers one question in DNS: is this address or domain on it? We ask 14 lists about IPs and 6 about domains.
Checked on arrival
Receiving servers ask the lists they trust about every message. Which lists they trust decides whether a listing costs you mail.
Questions
What is an email blacklist?
A list of IP addresses or domains seen sending spam, published in DNS so mail servers can check every incoming message against it in milliseconds. Lists are built from spam traps, user reports and traffic statistics. Each list decides on its own what gets an address listed and how it gets removed.
Will a blacklisting stop my mail reaching Gmail or Outlook?
Usually not by itself. Gmail and Outlook rely mostly on their own reputation data and on authentication (SPF, DKIM and DMARC). Blocklists matter more for company mail servers and spam filters, which often use Spamhaus, Barracuda and SpamCop. A listing on one of those can mean mail to businesses bounces; a listing on a small list rarely changes anything.
Why don't you check Google's or Microsoft's sending servers for my domain?
Mail you send through Google Workspace, Microsoft 365 or an email service goes out through servers shared by thousands of customers. Their reputation is the provider's to keep, and you couldn't delist them anyway. We check the addresses that are yours: single IPs in your SPF record and mail servers under your own domain.
How do I get removed from a blacklist?
Fix the cause first, or the listing comes back: a compromised account or website, a purchased list, or a server without reverse DNS. Then follow the list's own process; we link each one. Many lists expire listings on their own after a few days without new spam. Don't pay for express removal: the lists that matter don't charge.
How does the blacklist check work?
Every blocklist publishes its data in DNS. To check an IP, we reverse it and ask under the list's zone: 192.0.2.1 on SpamCop is the question 1.2.0.192.bl.spamcop.net. An answer in 127.0.0.x means listed, and the exact number says why; no answer means not listed. Domains are asked the same way. Lists refuse anonymous questions from public resolvers, so we ask from our own server. When a list declines or doesn't answer, we report that we couldn't check, never that you're listed.
What's the difference between IP and domain blocklists?
IP lists, such as Spamhaus ZEN, Barracuda and SpamCop, list the servers that send mail; receivers check the connecting server against them. Domain lists, such as Spamhaus DBL, SURBL and URIBL, list domains that appear in spam, including in links in the message body. A listed domain therefore hurts your mail even when it goes out through Google's or Microsoft's servers, while an IP listing only matters for mail sent from that server.