A global unsubscribe occurs when a subscriber chooses to unsubscribe from every email that anyone sends from Marketing Cloud Engagement.
Engagement manages a Global Unsubscribe list of those subscribers who opt out of all email coming from our platform. When someone opts out globally, they’re suppressed from every list created by an Engagement user. The former subscribers are marked with a red icon, and the Activate button in their properties panel is disabled.
You can't reactivate a subscriber from your Engagement account. Find out how a subscriber can request reactivation.
