Definition
Suppression list
Addresses and whole domains you will never email again: unsubscribes, complaints, clients and anyone who asked to be left alone.
A suppression list is a block list that sits above every campaign. Any address on it is excluded from sending no matter which list it appears in or which sequence it was meant for. A domain-level entry excludes everyone at a company. The list is fed automatically by unsubscribes and manually by you: existing customers, partners, competitors, people who complained, companies in the middle of a negotiation that sales does not want disturbed.
It matters because objections have to be permanent to count. A person who unsubscribed in March and receives a new campaign in June, because a fresh CSV contained their address, has a legitimate complaint and a reason to press “report spam”. Under legitimate interest, honouring an objection once and forever is part of what makes the basis stand up. Domain suppression covers the account-based case: when a company says it is not interested, or becomes a client, writing to a fifth person there is a mistake the list should make impossible.
In Seegnals the suppression list holds addresses and domains and can be exported as CSV. Suppressed addresses are caught on import, unsubscribe requests add to the list automatically, and the Opted out tile in campaign stats shows who left.