Email reputation
Spam-focused DNSBLs can influence whether mail is delivered, deferred or placed in spam.
IP reputation diagnostics
Check IP Blacklist Status
Review public IPv4 reputation signals used by email administrators, abuse teams and security systems.
5 public sources No account required Live DNSBL queries
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Check an IPv4 address
Enter a public server, mail gateway or internet-facing IPv4 address.
The address is queried against the listed DNSBL zones and is not stored by this tool. Results are reputation signals, not a security verdict. See our privacy policy.
Interpret results carefully
What an IP reputation check means
Security activity
Attack-reporting lists may flag addresses observed scanning, brute-forcing or abusing servers.
Private firewall data
Fortinet, Sophos, Cisco and other vendors maintain private feeds that this public tool cannot query.
If your IP is listed
- Check mail queues, server logs and active devices for compromise.
- Stop spam, malware, open relays, brute-force traffic or exposed services.
- Correct reverse DNS, SPF, DKIM and DMARC where email delivery is involved.
- Use the official source link to request review or removal.
IP blacklist questions
What is an IP blacklist?
An IP blacklist or DNSBL is a reputation dataset that identifies addresses associated with spam, compromised systems, attacks or other unwanted activity.
Does no listing mean an IP is completely safe?
No. It only means these sources returned no listing at the time of the check. Firewalls and security providers may use private reputation data that is not publicly searchable.
Why might a residential IP appear on a blacklist?
A compromised device, abusive traffic, shared carrier-grade NAT or a previous user of a dynamic address may affect its reputation.
How do I remove an IP from a blacklist?
Open the official source link, review its evidence and follow its removal process. First stop the underlying spam, malware or server compromise.
Can this tool check IPv6 addresses?
This release checks IPv4 because the selected public DNSBL sources do not all provide equivalent IPv6 query support.