When a fan first pre-saves a release and subscribes to Forever Saves, they'll get an email that gives them more information on the release, and a link to unsubscribe.

Once they follow the link, they'll be able to selectively unsubscribe from your email list and / or Forever Saves. If they opt out of emails, you won't be able to access their email data anymore within the Fans tab. If they opt out of "saving future releases", they won't be subscribed to save future releases.