content: The problem is that we are using many communications protocols in ways they were never really designed to be used, we have tacked thing on to it to increase capabilities and improve security but that is always going to be a stop gap measure.  No matter how big of a lock you put on a wooden door it is never going to be as strong as a reinforced steal door.  To have any hope of sorting out mid/long term internet/email security we would have to rebuild/redesign it from the ground up with security in mind, which is easier said than done (cost, lack of ubiquity causing people to not use the new architecture, vested interests, politics, logistics, etc).