Dear Thomas,
Did not get you completely, but trying to help from my understanding.
If you have Email Buttons tagging with proper tracking code and is you are capturing the same,
Site Catalyst Interface & Report Builder : Select 'Click-throughs' as metric in Tracking Code Dimension.
Workspace & Adhoc : Select 'Tracking Code Instances' as metric in Tracking Code Dimension.
Thank You!
Arun