De-listing Blacklisted IPs

This guide helps administrators remove their IP addresses from email blacklists to restore normal mail flow.

Email blacklists block IPs suspected of sending spam or malicious traffic. If your IP is blacklisted, emails may bounce or fail to deliver. This article covers:

• Why IPs get blacklisted
• Steps to resolve the issue
• Provider-specific removal processes
• Best practices to avoid recurrence

Why IPs Get Blacklisted

Common reasons include:

• Compromised servers sending spam.
• Open relay configurations on mail servers.
• High outbound mail volume without proper authentication.
• Poor list hygiene or sending to spam traps.

Before You Request De-listing

1. Identify the Root Cause

   • Scan for malware or unauthorized scripts.
   • Review mail logs for suspicious activity.
   • Verify SPF, DKIM, and DMARC records.

2. Stop the Spam

   • Suspend compromised accounts.
   • Patch vulnerabilities.
   • Implement outbound rate limits and filtering.

3. Check IP Reputation

   • Use a blacklist lookup tool:
     https://mxtoolbox.com/blacklists.aspx

De-listing Steps by Provider

Microsoft Services

• Hotmail / Live / Outlook

  • Submit a ticket:
    https://support.microsoft.com/en-us/getsupport?oaspworkflow=start_1.0.0.0&wfname=capsub&productkey=edfsmsbl3&ccsid=636384055665373784
  • Include:
    • Affected IP address
    • Bounce message details
    • Actions taken to fix the issue

• Office 365

  • Go to: https://sender.office.com/
  • Sign in with your Microsoft account.
  • Enter the blocked IP and request removal.

Generic Blacklist Removal

• Check which lists your IP is on via MXToolbox.
• Visit each blacklist provider’s site and follow their removal process:
  • Confirm IP is clean.
  • Agree to terms.
  • Wait for propagation (24–72 hours).

Best Practices to Prevent Future Blacklisting

• Maintain accurate DNS records (SPF, DKIM, DMARC).
• Monitor outbound mail volume.
• Regularly audit server security.
• Use suppression lists and feedback loops.

Troubleshooting Tips

• If removal fails, re-check for ongoing spam activity.
• Ensure reverse DNS (PTR) records match your mail server hostname.
• Consider using a dedicated outbound IP for email.