Suppression List

What is Suppression List?

A suppression list is a collection of email addresses that should never receive your messages. These lists are essential for compliance, reputation management, and respecting subscriber preferences. Suppression lists typically contain people who unsubscribed, marked your emails as spam, or bounced permanently.

Why it matters

Suppression lists protect your sender reputation by ensuring you don’t repeatedly send to people who don’t want or can’t receive your emails. They also help you comply with laws like CAN-SPAM and GDPR, which require honoring opt-out requests. Continuing to send to suppressed addresses can lead to Reported Spam, high Bounce Rates, and even blacklisting.

How it works

When a recipient unsubscribes, reports you as spam, or their email bounces permanently, your Email Service Provider (ESP) adds their address to the suppression list. Any future campaigns you send will automatically exclude these addresses. In AutoSend, suppression lists are organized into categories such as Global Unsubscribes, Unsubscribe Groups, Invalid Emails, and Bounced Emails.

Examples

• A subscriber opts out of newsletters—AutoSend moves them to the suppression list.

• An invalid email address causes a hard bounce—suppressed to prevent retry.

• A user marks a promotional email as spam—their address is automatically suppressed.

Best practices

• Don’t delete your suppression list—it ensures compliance.

• Regularly audit and export your suppression list to maintain transparency.

• Ensure your ESP syncs suppression lists across all campaigns and automation flows.

Related terms

Global Unsubscribes, Unsubscribe Groups, Invalid Emails, Reported Spam

FAQs

Can I manually add addresses to my suppression list?
Yes. If someone requests not to be contacted—even outside your unsubscribe process—you should manually add them to the suppression list to stay compliant and respectful.

What happens if I accidentally import suppressed addresses into a new campaign?
Your ESP should block those sends automatically. AutoSend ensures suppressed addresses are excluded from every campaign, even if you accidentally re-upload them.

Do suppression lists affect transactional emails?
It depends. For strictly functional transactional messages (like password resets), you may be allowed to bypass suppression. However, it’s best practice to confirm consent for all communication.