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Blacklist Checker
Check if a domain or IP address is listed on popular RBLs and spam blocklists like Spamhaus, SORBS, and others.
Enter a domain name or IP address to check against multiple blacklists
Blacklist Check Results for
Blacklist checker methodology
Blacklist checks use DNS-based blocklist lookups where the submitted IP address or domain is transformed into the query format expected by each list. A listing means that a specific list operator returned a positive response for that target.
How DNSBL/RBL lookups work
- IP-based lists usually reverse the IP octets and query a blacklist zone through DNS.
- Domain-based lists check the submitted domain or hostname against reputation zones.
- A negative result means the target was not listed by the checked source at query time, not that every mail provider will accept it.
Reputation interpretation
- IP reputation and domain reputation are different; a clean domain can send from a listed IP, and a clean IP can host a listed domain.
- False positives happen with shared hosting, recycled IP space, compromised accounts, and stale list data.
- Each blacklist operator controls its own evidence, policy, TTL, and delisting process.
Provider differences
- Large mailbox providers often combine private reputation systems with public DNSBL data.
- A public delisting does not guarantee immediate inbox placement at Gmail, Microsoft, Yahoo, or corporate mail gateways.
- Always investigate the sending IP, HELO/EHLO hostname, rDNS, SPF, DKIM, DMARC, and recent mail logs together.
Related checks
Most mail reputation systems score the sending IP separately from the domain. Shared mail servers, compromised accounts, or prior customer activity can affect an IP even when the domain has no listing.
The blacklist operator controls removal. OpsCheck can show the listing status, but delisting requests, evidence review, and TTL expiry are handled by the individual list provider.
No. Mail providers also evaluate SPF, DKIM, DMARC, sending history, message content, complaint rates, reverse DNS, and private reputation signals.