Free IT tools

Troubleshoot DNS, email, and connectivity problems faster.

Run practical diagnostics for the issues IT teams hit every day: unreachable hosts, DNS lookup problems, open ports, mail server misconfiguration, blacklist checks, and domain intelligence.

Black Lists

Check IPv4 against major DNSBL providers (MXToolbox-style blacklist agents).
Your current IP: Use my IP

How to use Black Lists checker

Enter an IPv4, hostname, or domain. For a domain, the checker resolves A and MX targets and tests their IPv4 addresses across major DNSBL providers.
Results show Listed, Not listed, or Unavailable per provider. Unavailable usually means timeout, provider-side policy, or retired zone.
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