DNS Blacklist Check
Check an IP against ~30 DNS-based blacklists for spam and abuse.
GET
/v1/blacklist
curl "https://dns.toolkitapi.io/v1/blacklist?ip=198.51.100.42"
import httpx
resp = httpx.get(
"https://dns.toolkitapi.io/v1/blacklist?ip=198.51.100.42",
)
print(resp.json())const resp = await fetch("https://dns.toolkitapi.io/v1/blacklist?ip=198.51.100.42", {
});
const data = await resp.json();
console.log(data);# See curl example
Response
200 OK
{
"ip": "198.51.100.42",
"blacklists_checked": 32,
"listed_count": 0,
"clean": true,
"results": [
{"blacklist": "zen.spamhaus.org", "name": "Spamhaus ZEN", "listed": false, "return_codes": [], "reason": null},
{"blacklist": "bl.spamcop.net", "name": "SpamCop", "listed": false, "return_codes": [], "reason": null},
{"blacklist": "b.barracudacentral.org", "name": "Barracuda", "listed": false, "return_codes": [], "reason": null}
],
"query_time_ms": 2145.6
}Try It Live
Live Demo
Response
Description
Check an IP against ~30 DNS-based blacklists for spam and abuse.
How to Use
1
1. Pass the IPv4 address in the `ip` parameter. 2. Check `clean` — `true` means the IP is not listed on any blacklist. 3. If listed, review `results` to see which blacklists flagged it and why.
About This Tool
DNS Blacklist Check queries an IP address against ~30 DNS-based blacklists including Spamhaus, SpamCop, Barracuda, SORBS, and others. It detects whether the IP is flagged for spam, malware, or other abuse — essential for email deliverability and IP reputation monitoring.
Why Use This Tool
- Email deliverability — Check if your mail server IP is blacklisted
- IP reputation — Verify a new IP's reputation before sending email
- Incident response — Check if a suspicious IP is known for abuse
- Server migration — Verify clean IP reputation before moving services
Frequently Asked Questions
Which blacklists are checked?
~30 including Spamhaus ZEN, SpamCop, Barracuda, SORBS, UCEPROTECT, Spamhaus DBL, and more.
What are return codes?
DNSBL return codes (like 127.0.0.2) indicate the type of listing — spam source, open relay, malware, etc. Each blacklist defines its own codes.
Start using DNS Blacklist Check now
Get your free API key and make your first request in under a minute.