Bulk DNSBL Lookup
Check one IPv4 address or a list against available DNSBLs before configuring outbound email. Each source gets a separate result.
What to do after the check
If an address is listed, use the corresponding operator’s official service: Spamhaus, SpamCop, UCEPROTECT, Barracuda or PSBL. Each operator sets its own removal requirements and timing.
Fix the root cause first: audit outbound SMTP, open relays, compromised accounts, PTR/HELO, SPF, DKIM, DMARC and sending rate.
External DNSBL availability changes. SORBS is not used because the service was decommissioned on June 5, 2024. A DNS resolver error can resemble a clean result, so verify critical findings on the operator’s website.
Frequently asked questions
How does DNSBL checking work?
The tool sends DNS queries to configured DNSBL zones. A returned listing record means the address was found in that specific list.
Is it safe for my IPs?
Yes. Queries go to public DNSBLs via the system resolver. We don't cache or publish your results.
Is bulk checking supported?
Yes. Paste a list into the textarea or upload a .txt file. For stability we limit to 100 IPs per run.
Does a clean result guarantee delivery?
No. DNSBLs are only one signal; receiving systems may also evaluate the domain, content, authentication and sending history.
