To move subscribers who have a status of 'Held' back to 'Active', NTO should extract those subscribers using a tracking extract or a data extract activity in automation studio, then import those subscribers as 'Active' using an import activity or file transfer activity in automation studio or an import wizard in email studio. This process will overwrite their status in all subscribers list and allow them to receive emails again. Contact Builder cannot mass update subscriber status in all subscribers list. Subscribers with a status of 'Held' cannot be re-enabled by contacting support unless there is a technical issue on Marketing Cloud's side that caused them to be held incorrectly. A SQL query cannot change subscriber status in all subscribers list directly. Reference: https://help.salesforce.com/articleView?id=sf.mc_es_held_status.htm&type=5 https://help.salesforce.com/articleView?id=sf.mc_es_import_subscribers.htm&type=5