386+ Tools Comprehensive Tools for Webmasters, Developers & Site Optimization

Email Blacklist Checker - Check IP Against Spam Blacklists

Email Blacklist Checker

We'll resolve the domain to its IP address
What are Email Blacklists?

Email blacklists (also called DNSBLs - DNS-based Blackhole Lists) are databases of IP addresses that have been reported for sending spam or malicious email. Mail servers use these lists to filter incoming messages and protect users from spam.

How This Tool Works
  1. Enter an IP address or domain name
  2. If you enter a domain, we'll resolve it to an IP address
  3. We check the IP against 10+ major email blacklists
  4. Results show which lists (if any) have your IP listed
  5. Use this information to identify and fix reputation issues
Blacklists We Check
  • Spamhaus ZEN: Composite list combining SBL, XBL, and PBL
  • Spamhaus SBL: Spam sources verified by Spamhaus
  • Spamhaus XBL: Exploited systems and malware
  • SpamCop: Automated spam trap network
  • SORBS: Various spam-related listings
  • Barracuda: Barracuda's reputation system
  • CBL: Composite Blocking List for compromised machines
  • UCEPROTECT: Multi-level blacklist service
  • PSBL: Passive Spam Block List
  • Mailspike: Reputation-based blacklist
What to Do If You're Listed
  1. Identify the cause: Check for compromised accounts, open relays, or spam complaints
  2. Fix the issue: Secure your mail server, remove malware, stop spam sources
  3. Request delisting: Visit the blacklist's website and follow their removal process
  4. Wait for automatic removal: Some lists auto-remove IPs after a period
  5. Monitor going forward: Regularly check blacklists to catch issues early
Example: Blacklist Check Output
IP: 192.0.2.100 Spamhaus ZEN: ✓ Not Listed SpamCop: ⚠️ LISTED - Action required SORBS: ✓ Not Listed Barracuda: ✓ Not Listed CBL: ✓ Not Listed Recommendation: Contact SpamCop to request delisting
Common Reasons for Blacklisting
  • Sending spam or unsolicited email
  • Compromised email accounts or servers
  • Open mail relay (allowing anyone to send through your server)
  • Malware or botnet activity
  • High complaint rates from recipients
  • Sharing an IP with a spammer (in shared hosting)
  • Poor email list hygiene (bounces, spam traps)
Prevention Best Practices
  • Implement SPF, DKIM, and DMARC authentication
  • Use double opt-in for email subscriptions
  • Monitor bounce rates and remove invalid addresses
  • Respond to abuse complaints promptly
  • Secure email accounts with strong passwords and 2FA
  • Rate limit outgoing email to prevent bulk sending
  • Regularly scan for malware and security vulnerabilities
  • Use dedicated IPs for important email sending
Delisting Resources
  • Spamhaus: https://www.spamhaus.org/lookup/
  • SpamCop: https://www.spamcop.net/bl.shtml
  • SORBS: http://www.sorbs.net/
  • Barracuda: http://www.barracudacentral.org/rbl/removal-request
Related Tools