Since the new CSA Rules of Procedure came into effect on 1 July 2019, One-Click Unsubscribe (RFC8058) is now a mandatory CSA criteria for newsletters. Senders are legally required to offer newsletter recipients a cost-neutral possibility to unsubscribe without requiring knowledge of log-in data. For a long time, this has been solved with unsubscribe links or buttons in the newsletter. The one-click unsubscribe link unsubscribes the recipient immediately from the newsletter. Making subscribers login or additionally confirm the cancellation of subscription is not permitted.