So prosecute them too.
L
The key phrase in those stories was that "people sent THEM classified e-mails..." Being "sent" e-mails (and the stories only say they were "classified," they don't say HOW they were classified) is far different than engaging in a deliberate and regular practice of hiding e-mail communications.
What did Powell and Rice do with classified e-mails if they received them? Did they hide them, delete them, attempt to cover them up? Who sent Powell and Rice classified e-mails? Was it someone on their staff, were they ordered to send them to their private accounts? This "Powell and Rice" story is a red herring.