Blacklist / RBL Checker

Check if an IP address appears on major email blacklists and DNS-based blocklists (DNSBL/RBL). Tests against Spamhaus ZEN, Barracuda, SpamCop, SORBS, UCEPROTECT, and more. Essential for email deliverability troubleshooting.

Example uses:

Diagnosing why outbound emails are being rejected, checking a new server IP before sending mail, monitoring your mail server's reputation, or verifying an IP has been delisted after remediation.

Blacklist / RBL Checker

Check if an IP address is listed on major email blacklists (DNSBL/RBL). Checks Spamhaus, Barracuda, SpamCop, SORBS, and more.