Blacklist (RBL / DNSBL) Check
Check an IP address or domain against 15+ reputable DNS-based blacklists in parallel. Identifies listings that may affect mail deliverability.
Check an IP or domain against DNS blacklists
Queries reputable free DNSBLs in parallel via DNS-over-HTTPS. A listing does not always mean mail will be blocked — different receivers consult different lists.
What gets checked
This tool fans out DNS queries to a set of free, reputable DNSBLs. For an IPv4 address it checks IP-reputation lists; for a domain it checks URI blacklists.
What a “listed” result means
A listing on one or two minor lists is rarely a problem — major mail receivers usually consult the top-tier lists only (Spamhaus, SpamCop, Barracuda). What matters is:
- Which list. Spamhaus ZEN has strong influence on mail routing; UCEPROTECT Level 3 does not.
- Why it’s listed. Each list has its own policy page explaining the return codes
(e.g.,
127.0.0.4vs127.0.0.10). - How to delist. Most lists have a self-service removal page; some require evidence that the underlying problem (open relay, compromised host, spamming customer) is fixed.
Caveats
- Some blacklists (notably Spamhaus via public resolvers) may rate-limit or refuse queries from shared resolvers. A “clean” result from a public resolver doesn’t guarantee you’re not listed on their private feeds.
- We only query free lists. Commercial feeds (Cisco Talos, Spamhaus DQS with registration, Proofpoint, Symantec) require accounts and aren’t included here.
- Blacklists are a signal, not a verdict. Mail deliverability depends on SPF, DKIM, DMARC, content, sending volume, and recipient-side signals, not just reputation lists.
Privacy
All queries go from your browser to Google Public DNS over HTTPS. We don’t proxy or log them.