DNSBL IP Check
DNSBL IP Check tests whether an IP appears on common DNS-based blocklist zones used in mail reputation systems.
π§ͺ Run this tool π Excessive Explanation β Frequently asked questions
π§ͺ Run this tool
π Excessive Explanation
𧩠Technical Details
What this tool checks
- Reverse-IP DNSBL query behavior across configured blocklist zones.
- Listed vs. not-listed evidence for each zone tested.
- Output summary suitable for deliverability triage and abuse response.
How to read the output
- Result Summary indicates listing risk level at a glance.
- Overview shows which zones triggered and which remained clear.
- Technical Details helps distinguish transient DNS issue vs. true listing.
- Raw Output can be attached in delisting or incident workflows.
Common failure patterns
- Listed sender IP causes widespread mailbox rejection or deferral.
- Dynamic/shared IP pools inherit poor reputation from prior users.
- DNS query failures mistaken for positive listings.
- Delisting completed in one zone but not others.
Remediation workflow
- Validate affected sending IPs and traffic source integrity.
- Resolve abuse source before requesting delisting.
- Re-test each listed zone after remediation window.
- Review SPF/DMARC/DKIM posture to prevent recurrence.
Next steps
β Frequently asked questions
Does listing in one DNSBL guarantee full mail outage?
Not always, but it significantly increases delivery risk depending on receiver policy.
Can DNSBL results change quickly?
Yes. Listings and delistings can change as reputation systems update.
Should I delist before fixing abuse source?
No. Sustainable recovery requires source control first.
Are all DNSBL zones equally important?
No. Prioritize zones relevant to your recipient mix.
How often should high-volume senders check DNSBL?
Continuously or at frequent intervals as part of deliverability operations.