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Blacklist checker.
Even perfect SPF, DKIM, and DMARC will not save you if your sending IP is already listed on a DNS-based blacklist (DNSBL). Enter a domain to resolve its mail-sending IP and check it against Spamhaus ZEN, SpamCop, and Barracuda.
01
We resolve your sending IP
A server-side MX/A lookup for the domain you enter — no signup, nothing stored.
02
We query three DNSBLs
Spamhaus ZEN, SpamCop, and Barracuda — the blacklists most receivers actually consult.
03
You get a clear verdict
Listed on any of the three is a fail — receivers reject or spam-folder that IP regardless of SPF/DKIM/DMARC.
Stop babysitting deliverability
CogniLead runs on a warmed sender pool with a reputation circuit-breaker that pauses a domain before it ever reaches a blacklist. You bring the leads.
Also try the SPF checker, the DMARC checker, or the spam-word checker.