Quickly find out if your IP address is listed on real-time blacklists (DNSBL/RBL). Protect email delivery and server reputation with a fast, reliable lookup
An IP blacklist check looks up an IP address on DNS-based blocklists (DNSBLs, also called RBLs). Mail servers query these lists to decide whether to accept mail from a sending IP, so a listing is one of the most common reasons legitimate email is rejected or filtered as spam. This tool checks a public IPv4 address against 8 lists, including Spamhaus ZEN, SpamCop and Barracuda.
Received: header of a message you sent, or ask your email provider.Private addresses and IPv6 can't be checked, and each visitor can run 6 checks per hour.
| List | What it lists |
|---|---|
Spamhaus ZEN (zen.spamhaus.org) | Combines the Spamhaus SBL (spam sources), XBL (compromised machines) and PBL (ranges that shouldn't send mail directly, such as home connections) |
SpamCop (bl.spamcop.net) | IPs reported by users for sending spam; listings expire automatically |
Barracuda (b.barracudacentral.org) | Barracuda's reputation list of IPs sending spam |
| PSBL, Mailspike, DroneBL, Backscatterer, UCEPROTECT Level 1 | Spam-trap hits, botnet and abuse sources, and servers sending backscatter (bounces to forged senders) |
127.255.255.x to refuse queries from public DNS resolvers), is reported this way instead of as "Not listed" or "Listed".Be wary of lists that charge for removal; reputable lists that mail providers rely on don't require payment.
A DNS-based blocklist: a list of IP addresses associated with spam or abuse, published through DNS so mail servers can check a sender quickly. RBL (Real-time Blackhole List) is an older name for the same thing.
A compromised account or device on your network may be sending it, or the address was used by someone else before you. Home and mobile IP ranges are often listed by policy because they aren't expected to run mail servers.
The list refused or failed our test query, so its answer for your IP couldn't be trusted. Lists sometimes rate-limit or block resolvers, and outages happen. Try again later, or look the IP up on that list's own website.
Not with this tool, which checks IPv4 only. Most blocklists focus on IPv4 because that is where most mail is still sent from.
Mostly no: these lists are used by mail servers. Some firewalls and forums also use them to block visitors, so a listed IP can occasionally have trouble reaching certain sites.