Suppression List Best Practices - How to Keep Your Email Game Strong

Suppresso the Mascot

Suppresso the Mascot

3 min read

Cartoon with emails attached to a wall

Did you know that by ignoring the hygiene of your email suppression lists, you’re losing money? Many email providers charge per processed email and this includes emails that aren’t sent because they’re on one or more suppression lists. This is in addition to any missing emails or negative sending reputation issues you may have encountered due to spam complaints or bounces. Let's delve into best practices to ensure your suppression lists work for you, not against you.

Understand the Basics

Before diving deep, grasp what suppression lists are and why they exist:

  • Definition: A suppression list is a list of email addresses to which you should not send emails. These can be due to unsubscriptions, hard bounces, or spam reports.
  • Purpose: They ensure compliance with email laws, protect sender reputation, and enhance overall deliverability.

Regularly Audit & Cleanse

Like any email list, suppression lists need regular attention:

  • Remove Transient Addresses: Some bounces or issues may be temporary. Review and cleanse your list periodically to ensure it's up-to-date and customers are receiving the emails necessary to use your application.
  • Update Your Source Email Lists: Periodically scan your primary email lists to weed out email addresses that have landed on your suppression lists to ensure you aren’t paying for emails that won’t be delivered
  • Sync Across Platforms: If you’re using multiple email platforms or tools for email marketing, ensure your suppression lists are synchronized between them. An email address removed or updated in one tool should reflect across all platforms to maintain uniformity and reduce discrepancies. SupMonster can help you maintain suppression list consistency.

Reinstate With Caution

Reinstating an email address from a suppression list should be a careful decision:

  • Re-evaluate: Ensure the reasons for initial suppression no longer exist. For instance, if an email address was marked due to a typo, ensure it's corrected before reinstating.
  • Seek Permission: Always reconfirm with users if they'd like to receive emails again, ideally using a different communication channel.
  • Educate the Customer: In cases where customers have accidentally unsubscribed from your email, or used “mark as spam” to stop a user-scheduled email feed, take time to educate them on the proper ways to unsubscribe, and the implications of marking emails as spam.

Empower Your Team

  • Training: Regularly train your email marketing team on the importance and best practices of suppression list management.

  • Provide the Right Tools: Ensure your customer support team is empowered with tools to self-diagnose email deliverability problems including searching and removing emails from suppression lists across your subscribed email platforms. SupMonster makes it easy for customer support agents and marketing teams to manage suppression lists without the need for developer assistance.


A well-managed suppression list is more than just a compliance tool; it's a strategic asset in optimizing your email communications. By adhering to best practices and using tools designed for the purpose, you can ensure your emails reach their intended recipients and you aren’t paying for undelivered emails. SupMonster is here to make this journey seamless and effective for you.