Docs · Intelligence
DNSBL blacklist check
Check an IP or domain against the major DNSBLs in parallel: Spamhaus ZEN, Barracuda, SpamCop, SORBS, PSBL, SURBL.
POST
/v1/intel/blacklist Reverses the IP, appends each blocklist zone, queries A. An answer means listed; NXDOMAIN means clean. Six blocklists checked, in parallel. Domain-based checks target SURBL multi. Deliverability and email-ops teams use this on every outbound IP. Cheap and rate-safe — DNSBL operators publish these zones for exactly this kind of query.
Supported
Six major DNSBLs in parallel: Spamhaus ZEN (covers SBL+CSS+XBL+PBL), Barracuda, SpamCop, SORBS, PSBL, SURBL.
Not supported
IPv6 (most DNSBL operators do not yet publish v6 zones). Bulk IP scans — issue one call per IP rather than passing a list.
Parameters
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
| target | string | yes | — | An IPv4 address (preferred) or a domain. IPv6 not yet supported by most DNSBL operators. |
Request
curl -X POST https://api.qcrawl.com/v1/intel/blacklist \
-H "Authorization: Bearer osk_..." \
-d '{"target": "8.8.8.8"}'Response
{
"status": "success",
"target": "8.8.8.8",
"is_ip": true,
"listed_count": 0,
"checked_count": 6,
"results": [
{"zone": "zen.spamhaus.org", "name": "Spamhaus ZEN", "listed": false, "answer": null, "applicable": true},
{"zone": "b.barracudacentral.org", "name": "Barracuda", "listed": false, "answer": null, "applicable": true},
...
]
}