Email Blacklist Checker
Check if your server IP or domain is flagged on real-time DNSBL spam databases. Essential diagnostics for cold emailers, SMTP providers, and businesses.
Deliverability & Blacklists FAQ
Essential insights for marketers, businesses, and SMTP operators to protect domain reputation.
Why did my IP/domain get blacklisted?
DNSBL listings typically happen when:
• Your server sent emails to a spam trap (dormant decoy addresses).
• Your recipient lists are stale, producing excessive bounces.
• Users actively hit "Report Spam" on your marketing letters.
• A malware infection compromised your mail server, causing unauthorized spam blasts.
How do I delist my IP or domain?
Follow these standard removal guidelines:
• Spamhaus ZEN: Visit the Spamhaus lookup page, submit your IP, and request a self-service removal if your spam issue is resolved.
• SpamCop: Listings automatically expire after 24 hours of zero spam activity. Find and stop the source of spam immediately.
• SORBS/UCEPROTECT: Visit their directory websites. Most standard listings provide free removal forms once active spam signs stop.
What is DNS Health & Spam Traps?
DNSBLs rely heavily on DNS Health metrics. Always make sure your mail server has a valid Reverse DNS (rDNS/PTR record) matching your domain name. Many blacklists automatically flag servers that lack fully matching forward-confirmed PTR records, recognizing them as residential or unsecured nodes.
Best practices for marketers
Maximize email inbox rates by keeping sender status clean:
• Enable fully validated SPF, DKIM, and DMARC records on all domains.
• Never buy email lists; implement Double Opt-In (DOI).
• Monitor bounce rates and keep them strictly below 2%.
• Warm up your sender IPs gradually and rotate outbound SMTP channels.