ONLINE
Deliverability Letter

Suppression List

Also known as: Exclusion List

A suppression list is the place your email tool keeps addresses that should not receive messages. It is a permanent "do not send" list that helps you avoid emailing people who have opted out or caused issues in the past.

A suppression list is your email tool's do not send list. It stores email addresses that should not get messages from you anymore. This usually includes people who unsubscribed, hard bounces, and contacts who reported spam. Once an address is on this list, your system should skip it for all future sends.

A good suppression list protects your sender reputation and keeps you compliant. It stops you from emailing people who clearly said they do not want your messages. It also reduces bounces and spam complaints, which helps you stay in the inbox for people who still want to hear from you. Most platforms update this list automatically based on user actions.

Make it a habit to never remove addresses from your suppression list. If someone wants to sign up again, let them opt in with a fresh form so you have a new record of consent. You can also add risky contacts manually, like role based addresses such as info@example.com or old lists you do not trust. This keeps your list clean and your deliverability strong.