DNS Blacklist Checker — Domain DBL & URIBL Lookup

IP blocklists score IPv4 and IPv6 addresses seen in SMTP connections or attack traffic. Domain blocklists encode the hostname portion of URLs and mail links — Spamhaus DBL, URIBL, and ZRD fall in this category. A spotless sending IP can still fail when message bodies link to a DBL-listed domain.

Our note field in results reminds operators to check both layers. Marketing teams debugging form notifications should run domain DBL on link domains; mail ops should still scan outbound SMTP IPs separately.

Spamhaus DBL lists domains seen in spam or malicious email contexts. URIBL multi covers multi-source URI reputation aggregation. Spamhaus ZRD targets newly registered or young domains with elevated risk signals. Each query uses standard DNSBL inversion — listed returns true when the DNS answer indicates membership.

listedOn enumerates human-readable list names for hits. Zero hits yields summary text stating the domain was not listed on checked zones at query time.

Common causes include compromised WordPress sites serving malware paths, phishing pages on subdomains, affiliate spam campaigns using your brand domain, and URL shortener abuse. Legitimate delisting requires remediation at the host plus operator delist requests where applicable.

Stale listings sometimes persist after cleanup until crawlers re-verify. Re-check daily after fixes; document listedOn before and after for provider tickets.

DBL semantics often evaluate the domain label you query. Checking www.example.com versus example.com can differ when only a subdomain path triggered listing. Start with apex, then test specific hostnames appearing in bounce messages or Safe Browsing alerts.

Wildcard-compromised subdomains may list parent zones depending on operator policy — investigate hosting logs alongside DBL hits.

Mail abuse desks attach DBL results to outbound campaign tickets when corporate domains appear on blocklists. Web security attaches the same export when marketing landing pages trigger URIBL hits from third-party trackers.

Combine with domain reputation checker for SPF, DMARC, and WHOIS age context on the same string.

DNSBL over DNS is fast but coarse. Network timeouts can resemble clean answers; some list operators rate-limit heavy automation. A single clean scan does not guarantee future cleanliness if attackers later compromise the site.

Conversely, listed on one list may not mean every receiver blocks you — different MTAs consult different zones. Still treat any hit as actionable.

Remove malware, close open redirects, revoke compromised CMS accounts, and patch vulnerable plugins before requesting delist. Spamhaus and URIBL publish operator guidance — follow their portals; our tool is read-only diagnostics.

After delist, lower TTL temporarily if you must swap A records to a clean host during recovery.

Automate with GET /ip-tools/api/extended?action=domain-blacklist&domain=example.com. Alert when listed flips true on production marketing domains. Store JSON nightly for compliance evidence.

Respect rate limits — batch scans should sleep between domains.

Both pages call domain-blacklist with identical backend shape. DNS blacklist checker emphasizes mail and URI blocklist terminology; malicious domain DNS checker frames results for threat triage workflows. Use either page — API action is the same.

Follow domain hits with threat intel lookup and phishing domain checker for broader context.