From Blacklisted to Whitelisted: Resolving SMTP Rejections and Securing Email Delivery


“Dear expert, our company’s webmail system has been flagged as spam and is now on a blacklist. While incoming emails are received without issue, any attempt to send emails fails. The error returned is an SMTP rejection from the recipient’s mail server after the RCPT TO command, indicating ‘JunkMail rejected’ by What steps can we take to resolve this and restore our email sending capabilities?”


Step 1: Identify the Cause

Firstly, determine why your webmail was blacklisted. Common reasons include:

  • Spam-like behavior: Sending large volumes of unsolicited emails.
  • Compromised accounts: Unauthorized access leading to spam distribution.
  • Email content: Certain keywords or patterns may trigger spam filters.
  • Step 2: Secure Your Email System

    Ensure that your email system is secure and not compromised by:

  • Changing passwords for all accounts.
  • Updating security protocols and software.
  • Implementing two-factor authentication where possible.
  • Step 3: Review Email Practices

    Review your email sending practices to ensure they comply with best practices:

  • Consent: Only send emails to recipients who have opted in.
  • Content: Avoid using language that is typically flagged as spam.
  • Frequency: Regulate the number of emails sent to avoid being marked as spam.
  • Step 4: Contact the Blacklist Operator

    Reach out to the blacklist operator (in this case, to:

  • Request details about the specific reasons for blacklisting.
  • Submit a removal request after addressing the issues.
  • Step 5: Monitor Your Email Reputation

    After resolution, continuously monitor your email reputation by:

  • Using email reputation services to track your status.
  • Regularly checking blacklists to ensure you remain clear.
  • Step 6: Implement Preventative Measures

    Finally, prevent future occurrences by:

  • Educating staff on proper email usage.
  • Regularly auditing your email system for vulnerabilities.
  • By following these steps, you can work towards having your webmail removed from the blacklist and restoring full email functionality. Remember, maintaining good email practices is key to avoiding future blacklisting.

    Leave a Reply

    Your email address will not be published. Required fields are marked *

    Privacy Terms Contacts About Us