Confirm Email Subscribers


I am using the plugins Mailsubscribers, Mailshot and Postman for one of my projects to send newsletters. We’ve now decided to change from double opt-in to single opt-in. But at the moment, there are still some email addresses not confirmed yet. I’ve tried to switch them from « not registered » to « active » in the back-end manually, but that didn’t work
Does anyone know if it is possible to do that manually?
Thank you!