blacklist checker
Use this working tool to inspect structure, plan credits, or query a domain without confusing that action with mailbox verification.
Blacklist signals, answered.
What does the blacklist score measure?+
It summarizes the selected DNS blocklist signals checked for the resolved public IPv4 address. It is not a universal sender-reputation score.
What does Clear mean?+
No listing signal was returned by that specific blocklist at the time of the lookup.
What does Listed mean?+
That blocklist returned a listing signal for the checked IP. Confirm the result with the list operator before taking action.
What does Unknown mean?+
The lookup was unavailable or inconclusive. Unknown is not the same as Clear.
Which blocklists are checked?+
The tool checks Spamhaus ZEN, SpamCop Blocking List, and Barracuda Reputation Block List signals. Coverage is intentionally limited and transparent.
Can a clean result guarantee inbox placement?+
No. Inbox placement also depends on authentication, reputation, complaints, bounces, content, engagement, and recipient policy.
Why does a domain resolve to more than one IP?+
Domains can use multiple mail servers. The checker evaluates up to three returned public IPv4 addresses so results remain quick to understand.
Can this tool check IPv6?+
The current public checker evaluates IPv4 addresses. IPv6 blocklist coverage can be added as a separate enhancement.
How often should I run a blacklist check?+
Run it after a sudden bounce or complaint increase, a sending-domain change, or a blocklist notification. Avoid treating a single snapshot as a permanent status.
What should I do if my IP is Listed?+
Confirm the listing, review recent bounces and complaints, fix authentication, pause risky sending, and follow the blocklist operators removal guidance.
Does Refresh List contact the mail server?+
No. It uses DNS lookups only and does not send email or open an SMTP session.