The E-mail unsubscribe link is the one of jive8 new feature. There is one path to unsubscribe email notifications. i.e , Admin Console: System > Settings > Message Templates . Then Click the edit icon for the Email Footer template. In that , Option is there you should enable to YES . Then after click Save Changes . Actually , this is the way to stop email notifications but , if i forward one email to X user (example) if he want to stop email notifications from me he can click on unsubscribe link and login in to oracle community then can change Email Preferences.
Other than this, any other way is there to stop E-mail Notifications.
Actually , how we can protect this scenario ?
Reviewing through the scenarios you have listed above:
1. clicking on the "unsubscribe link"
2. modifying your user preferences so that you are not notified via email
These cover the main 2 options, however if you are wanting to disable all email notifications from your instance there is also the option to disable your outgoing mail server (admin console >> system >> settings >> email server >> outgoing).