Home / DNSBL Blacklist Checker
PUBLIC WEB DIAGNOSTIC
DNSBL Blacklist Checker
Check a public IPv4 address against bounded DNS lists.
Methodology
Accept a public IPv4 address only, reverse its octets, and make bounded DNSBL lookups. Each list is reported separately.
What the result means
Listed, clear or unavailable list results. Treat it as a practical observation rather than a guarantee about every user or provider.
Limitations
A listing is not a universal delivery verdict. Unavailable results are reported honestly instead of guessed.
Worked example
For 93.184.216.34, the lookup name begins 34.216.184.93. A clear result means only that one list gave no A response.
FAQ
Does it prove delivery failure?
No. Mail providers use many independent signals.