Suppression lists

The suppression list is a workspace-wide blocklist checked at send time — the last gate before any message leaves. A suppressed contact can sit in lists and campaigns all day; no email will ever be sent to them. It's the mechanism that makes unsubscribes permanent, keeps customers out of cold sequences, and stops bounced addresses from being hit twice.

How addresses get suppressed

• Unsubscribes — every unsubscribe click or reply ("remove me", "stop", "unsubscribe") adds the address automatically and permanently.
• Hard bounces — an address that hard-bounces once is suppressed so it can't damage a second campaign.
• Spam complaints — complaint feedback suppresses the address immediately.
• Manual entries — add individual addresses or upload a CSV under Contacts → Suppressions. You can suppress a whole domain (for example bigcustomer.com) to fence off an entire company.
• API — POST /api/v1/suppressions for syncing from your CRM.

Seed it before your first campaign

Before launching anything, upload: current customers, active sales opportunities, partners and investors, and every historical unsubscribe from any previous tool you used. Cold-emailing an existing customer is embarrassing; cold-emailing someone who unsubscribed from your old tool is a legal problem in most jurisdictions.

Behavior details

• Suppression wins over everything — a suppressed contact in ten lists and five campaigns receives zero sends from any of them.
• Checks are case-insensitive and run at send time, so adding an entry mid-campaign stops the remaining steps to that address.
• Unsubscribe- and complaint-sourced entries can't be deleted from the dashboard; manual and bounce entries can, with an audit-log record of who removed them and when.
• Suppressions are exportable as CSV for compliance requests.