We host our preference center in Sales Cloud (visual force page). The unsubscribes are synced to Marketing Cloud via the Individual Object (automation studio).
What we miss is tracking for each email, how many subscribers have unsubscribed (this in only shown for unsubscribe replies) and not for those who have unsubscribed via the custom prefence page.
How can we make sure this unsubscribe info (including the email ID(?)) is pushed back to SFMC? I know this is possible via the API but it is still vague for me..
Thank you very much!