Domain resolution
Resolve the domain to website IP addresses before checking reputation.
100% Free • No Signup • Reputation Check
![]()
Blacklist Checker
Check domain and IP reputation across configured blacklist and DNSBL sources.
Related checks: Investigate reverse DNS, SPF, DMARC and domain health.
Free lookup • Domain & IP • No signup
Results depend on connected DNSBL/reputation sources. We show exactly which lists were checked.
Why blacklist status matters
Email providers and security tools use DNSBL and reputation lists to decide whether to accept or reject mail. A listed IP or domain can cause delivery failures, spam folder placement or blocked connections — even when SPF, DKIM and DMARC look fine.
What this checker reviews
One check reviews domain, website IP and mail server reputation signals where integrations are available.
Mail server IPs
Find MX records and check the IPs used by mail servers.
DNSBL lists
Check configured DNS-based blacklist providers.
Listed status
Show exactly which lists report a match.
Lookup errors
Separate clean results from timeouts, unavailable providers and unsupported checks.
Email deliverability context
Explain how blacklist status can affect email delivery and sender reputation.
Common blacklist issues this tool can detect
Find reputation signals that may affect email delivery or infrastructure trust.
Listings & reputation
- Domain or IP appears on a blacklist
- Website IP appears on a reputation list
- Listed status reported by connected DNSBLs
Mail server IPs
- Mail server IP appears on a DNSBL
- MX-resolved IPs checked separately
- PTR gaps may affect mail reputation
Provider status
- Some blacklist providers timed out
- Providers unavailable or rate limited
- Blacklist providers not connected yet
Deliverability context
- Blacklist is only one delivery signal
- SPF, DKIM and DMARC also matter
- Reverse DNS affects mail server trust
For PTR or MX side-checks, use Reverse DNS Checker and MX Lookup.
How blacklist checking works
The checker resolves domain and mail server IPs, then checks configured reputation sources.
Enter a domain or IP
We clean the input, detect whether it is a domain or IP address, and validate the format.
Resolve related IPs
For domains, we check website IPs, MX records and mail server IPs where possible.
Check configured lists
The tool checks configured DNSBL or reputation providers and reports only real lookup results.
When to check blacklist status
- After changing server or IP address
- When mail delivery problems start
- Before launching a new mail server
- After a security incident or abuse report
- Before bulk or transactional sending
- Periodic reputation monitoring
Understanding blacklist results
Clear
The checked IP or domain was not listed on the connected lists.
Listed
One or more connected lists returned a blacklist match.
Partial
Some checks completed, but one or more providers timed out or were unavailable.
Not connected
Blacklist providers are not connected yet, so no live reputation verdict is available.
Blacklist status is only one deliverability signal. SPF, DKIM, DMARC and reverse DNS also matter.
Provider status: Results are shown only when real DNSBL sources are connected. Listed matches, timeouts and not-connected states are reported separately — no reputation verdict is shown without active providers.
Preparing blacklist check…
Need help reviewing blacklist or reputation issues?
Send us your domain or IP report and we’ll review the issue.
Learn more: What is a DNSBL?
Blacklist status can change quickly. A clear result at lookup time does not guarantee future reputation. How we check
Frequently asked questions
A blacklist check reviews whether a domain or IP appears on configured reputation or DNSBL lists.
A DNSBL is a DNS-based blacklist used by some mail systems and security tools to identify suspicious or abusive IP addresses.
No. Blacklist status is only one signal. SPF, DKIM, DMARC, reverse DNS, content quality and sending behavior also affect delivery.
Some providers may be unavailable, rate limited or not configured. Timeouts should be treated separately from blacklist matches.
Removal depends on the blacklist provider. Usually you must fix the underlying issue first, then request delisting from the provider.