This will be a 2.2.0 feature - we did away with the combersome admin-side e-mail manager, and added the ability for the admin to log in to users' accounts directly, adding a couple necessary special options (i.e. Move to another user's Inbox) only available in this special admin login mode. With the number of features needing template changes (for example, nested folders) it wasn't worth trying to keep the admin interface in sync with the two user-side template sets. You still won't be able to search for users who are(n't) forwarding their e-mail, but you will be able to quickly take a look in their account settings to find out if a given user has turned on forwarding.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com