The Electronic Frontier Foundation (EFF) has a good summary of the laws governing email privacy protections in the context of the scandal that led to the resignation of General David Petraeus, the Director of the Central Intelligence Agency. At the heart of the protections afforded to email is the The Electronic Communications Privacy Act (ECPA) from 1986. The EFF article explains how ECPA applies in this case, but is seriously outdated and doesn’t seem to offer much protection at all.