Track Email Subscription Opt-in timestamp and Opt-in renewal
Due to Legal obligations, many clients after 2 years that a Contact doesn't renew the Opt-in to a specific Email Subscription must stop communications via that Subscription type.
Due to the impossibility of tracking the updates of the Email Subscriptions (there isn't a default date property that tracks this event, nor the possibility to re-enrol the contact in a workflow to set a timestamp in a custom property), it becomes impossible to track the timestamps and so postpone the term of the 2 years period.
