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Blacklist Checker

Check whether your IP or domain is blacklisted in popular DNS-RBLs.

Why check IP and domain blacklists

DNSBLs (Spamhaus, SpamCop, Barracuda and others) are databases of IPs and domains caught sending spam. Receiving mail servers query them on every incoming message: a listing in even one major blacklist can drop your deliverability to zero.

Check your SMTP server’s IP and your sending domain before launching a campaign and after any delivery complaints. If you are listed, fix the root cause first (compromised account, open relay, recipient complaints), then request delisting.

Signs you are blacklisted

  • A sudden spike in 550/554 bounces;
  • Bounce text mentioning Spamhaus, RBL or a blocklist;
  • Mail failing only to specific providers.