Contacts are allowed to unsubscribe from all emails sent via messages and events.
Organization admins may view a list of those unsubscribed contacts.
- In Contacts > Manage Contacts, Choose Filters, then select the checkbox for Email status and choose Unsubscribed.
- Click Apply to view the Unsubscribed Contacts
- Bounced emails are described here: Manage Blocked Email addresses
There is also a notice in an unsubscribed contacts profile to indicate that they are unsubscribed.