Summary
The overwhelming consensus from experts, marketers, and email service provider documentation is that suppression lists prevent transactional emails from being delivered. These lists, which contain addresses that have unsubscribed, hard bounced, or marked emails as spam, are designed to protect sender reputation and ensure compliance. Sending any type of email, including transactional messages, to addresses on a suppression list is detrimental to deliverability and can lead to penalties, including blacklisting. Maintaining proper list hygiene and honoring suppression lists are crucial for successful email marketing.
Key findings
- Universal Suppression: Suppression lists generally apply to all types of email, including transactional messages.
- Reputation Damage: Sending emails to addresses on suppression lists harms sender reputation and deliverability.
- Compliance Requirement: Honoring unsubscribe requests and suppression lists is essential for compliance and ethical email marketing.
- Automated Blocking: Many ESPs automatically add bounced or unsubscribed addresses to suppression lists and block future sends.
Key considerations
- List Management: Implement rigorous list management practices to maintain a clean and up-to-date suppression list.
- Transactional Policy: Ensure transactional email systems are configured to respect suppression lists.
- ESP Configuration: Understand how your ESP handles suppression and verify that it's properly configured.
- Reactivation Process: Establish a clear process for reactivating addresses that have been suppressed when appropriate.
- Regular Checks: Periodically review suppression lists to ensure accuracy and effectiveness.
What email marketers say
9 marketer opinions
The consensus among email marketers is that suppression lists prevent transactional emails from being delivered. These lists contain contacts who have unsubscribed, hard bounced, or marked emails as spam. Sending any email, including transactional ones, to these addresses can harm sender reputation, lead to deliverability issues, and potentially result in blacklisting. Maintaining good list hygiene and respecting suppression lists are crucial for email marketing success.
Key opinions
- Suppression Impact: Suppression lists block transactional emails to maintain compliance and protect sender reputation.
- Reputation Risk: Sending transactional emails to suppressed addresses damages sender reputation and increases the risk of being marked as spam.
- Compliance: Honoring suppression lists ensures compliance with opt-out requests and improves overall deliverability.
- List Hygiene: Maintaining a clean email list by promptly adding unsubscribes, bounces, and spam complaints to suppression lists is essential.
Key considerations
- Programmatic Checks: Implement programmatic checks to ensure no emails are sent to addresses on the suppression list.
- ESP Verification: Verify that your ESP automatically handles suppression and suppresses transactional emails appropriately.
- Sender Reputation: Prioritize sender reputation by regularly cleaning and maintaining your email list to avoid deliverability problems.
- Transactional Email Handling: Ensure all unsubscribe requests are honoured, and not sending further transactional emails to these contacts.
Marketer view
Email marketer from HubSpot responds that suppression lists are critical for maintaining email marketing health. If an email address is on the suppression list (due to unsubscribe, bounce, or spam complaint), all emails, including transactional ones, should be suppressed. This helps maintain a positive sender reputation.
12 Aug 2024 - HubSpot
Marketer view
Email marketer from Litmus responds that a good email list hygiene involves respecting unsubscribes and suppression lists. Continuing to send transactional emails to suppressed addresses can damage your reputation and get you blocklisted. Always check your suppression list before sending any email.
8 Jan 2024 - Litmus
What the experts say
3 expert opinions
Experts agree that suppression lists generally affect all email communications, including transactional emails. Sending transactional emails to addresses on the suppression list is detrimental to sender reputation and can lead to deliverability issues. Respecting unsubscribe requests and maintaining a clean list are crucial for optimal sending and deliverability.
Key opinions
- Global Suppression: Suppression lists typically affect all email types, including transactional messages.
- Reputation Harm: Sending transactional emails to suppressed addresses harms sender reputation and deliverability.
- Importance of Respect: Honoring unsubscribe requests and suppression lists is critical for good email practices.
Key considerations
- Clean List Maintenance: Maintain a clean email list by promptly removing unsubscribed recipients.
- Transactional Email Handling: Ensure transactional emails also adhere to suppression lists to avoid deliverability issues.
- ESP Behavior: Understand how your ESP handles suppression and its impact on all email types.
Expert view
Expert from Spamresource.com explains that suppression lists should apply to all types of emails, including transactional ones. Sending transactional emails to addresses on the suppression list can harm your sender reputation and lead to deliverability issues. They emphasize that respecting suppression lists is crucial for maintaining good email practices.
24 Dec 2022 - Spamresource.com
Expert view
Expert from Word to the Wise responds that it is critical to ensure your transactional emails also honor the unsubscribe requests in your suppression lists. They recommend maintaining a clean list for optimal sending and deliverability, which includes suppressing all emails when a recipient has unsubscribed.
13 Oct 2021 - Word to the Wise
What the documentation says
5 technical articles
Email service providers like AWS, Twilio SendGrid, Mailchimp, Postmark, and Google Workspace employ suppression lists to prevent sending emails, including transactional ones, to addresses that have bounced or unsubscribed. This automated process safeguards sender reputation and prevents emails from being marked as spam. Manual intervention is often required to remove addresses from these lists if future communication is desired.
Key findings
- Automated Suppression: ESPs automatically add bounced or unsubscribed addresses to suppression lists.
- Transactional Blocking: Suppression lists prevent the sending of all email types, including transactional emails.
- Reputation Protection: Suppression protects sender reputation and prevents emails from being marked as spam.
- Manual Removal: Addresses must be manually removed from suppression lists if future communication is desired.
Key considerations
- Bounce Handling: Understand how the ESP handles bounces and adds addresses to the suppression list.
- List Cleaning: Regularly clean email lists to remove invalid and inactive addresses.
- Unsubscribe Management: Immediately honor unsubscribe requests and add addresses to the suppression list.
- Reactivation Process: Understand the process for reactivating addresses that have been suppressed.
Technical article
Documentation from Google Workspace explains that sending to unsubscribed users can result in your email being marked as spam. They recommend immediately removing unsubscribed recipients from your mailing list and honouring all unsubscribe requests. Continuing to send to these recipients, including transactional emails, will damage your sender reputation and may result in your emails being sent to spam.
4 Dec 2023 - Google Workspace
Technical article
Documentation from Twilio SendGrid shares that Global Suppressions prevent you from sending email to addresses that have previously bounced or unsubscribed from your mail. This suppression affects all email types, including transactional, to protect your sender reputation. To send to these addresses again, they must be manually removed from the suppression list.
24 Nov 2023 - Twilio SendGrid
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