Hello @StevenM7658 ,
If you have a contact that accidentally unsubscribed and can't find the resubscribe confirmation email, we do have an alternative method. You can get an email directly from that email address explicitly stating they want to be resubscribed. Once you have that, please call our Review team, and they will assist from there.
Due to the legal and Compliance nature of email subscriptions, we do need to ensure that a process is followed to ensure contacts are only receiving emails they've given permission to receive. If you have any other questions or need any clarifications, feel free to reply here or make a new thread and we'll be happy to assist.