1. Overview

An email suppression list is a collection of email addresses that should not receive communications. These addresses are excluded to protect sender reputation, improve deliverability, and ensure compliance with anti-spam regulations like the CAN-SPAM Act.


2. Purpose of Suppression Lists

  • Prevent sending emails to disengaged or invalid recipients

  • Protect sender reputation with ISPs

  • Reduce bounce and spam complaint rates

  • Ensure legal and regulatory compliance

  • Improve campaign engagement metrics

3. Types of Suppression Records

3.1 Spam Complaints

  • Recipients who mark emails as spam

  • High risk for domain/IP reputation

3.2 Unsubscribes

  • Users who opt out of communications

  • Must be immediately suppressed

3.3 Bounced / Blocked / Invalid Emails

  • Hard bounces (non-existent emails)

  • Blocked by servers or policies

  • Invalid or malformed addresses

3.4 Verification-Based Suppressions

Generated via email verification:

  • Spam traps

  • Abuse reports

  • Disposable emails

  • Do-Not-Email flags

4. Suppression Handling in MassMailer

Automatic Suppression Creation

MassMailer automatically creates suppression records when:

  • Unsubscribe events occur

  • Spam reports are detected

  • Hard bounces happen

  • Email verification flags invalid or risky emails

Auto-Suppression Behavior

  • Suppressed emails are automatically excluded from all campaigns

  • No manual filtering required during sends

5. Managing Suppressions in MassMailer

5.1 View Suppression Records

Navigate to:

  • MassMailer → Suppressions Tab

  • Filter by type:

    • Bounces

    • Spam Reports

    • Global Unsubscribes

    • Blocks

    • Invalid Emails

5.2 Un-Suppress an Email (Re-enable Contact)

Step 1: Update Record in Salesforce

  • Open Contact/Lead record

  • Uncheck:

    • Email Opt Out

    • Invalid Contact/Lead

Step 2: Remove from Suppression List

  • Go to MassMailer → Suppressions

  • Search email address

  • Select record

  • Click Delete/Remove

6. Best Practices

List Hygiene

  • Regularly clean email lists

  • Remove inactive or invalid users

Compliance

  • Always honor unsubscribe requests

  • Maintain audit logs for suppression actions

Monitoring

  • Track:

    • Bounce rates

    • Spam complaints

    • Unsubscribe trends

Verification Integration

  • Use email verification tools before campaigns

  • Auto-suppress risky email categories


7. Conclusion

Managing suppression lists in MassMailer is essential for maintaining a healthy email ecosystem within Salesforce. By automating suppression handling and following best practices, organizations can ensure high deliverability, compliance, and meaningful engagement with their audience.


For more information, you can refer to the blog post.