By law, once a contact unsubscribes you are not able to send them another campaign. So you do not have the ability to update the status back to active at any time. This contact will remain unsubscribed and not receive any marketing campaigns for the duration of your use of the iVvy system.
If the contact has unsubscribed by mistake, then they can contact iVvy in writing directly from the “unsubscribed” email and request to be resubscribed. Any other form of request such as a phone call, or from any other email addresses will not be accepted, as legal proof of ownership of the email in question will be required to re-subscribe.