In our system we have a unique use case where multiple entities are using the system. We need to have an "unsubscribe from all" only for their business unit, not the entire CRM system. So for example, we have two distinct university alumni entities using the CRM solution (we actually have 4). They each of a "Solicitations" and "Newsletter" subscription list. They also want to give them an option of unsubscribing from all of their subscription lists but not the other universities. So in this case two landing pages would be used, only offering the related subscription lists, but how would you make one check box which would be "unsubscribe all", but it would only do the subscription lists listed on the page (their business units subscription lists).
Example:
University A
Subscription List Solicitations
Subscription List: Newsletter
University B
Subscription List Solicitations
Subscription List: Newsletter
Normally, there is only one entity using the CRM system, so by having no subscription lists assigned to a unsubscribe record, it drops them from all lists, which works. We don't want to do that, because we share with several entities who manage their subscriptions separately, but use the same source system. How would you best tackle this? I have some ideas, but want to see what you recommend.