This is a feature available to enterprises in Exchange server and it works quite well, especially for messages with sensitive content. The key difference is th

This is a feature available to enterprises in Exchange server and it works quite well, especially for messages with sensitive content. The key difference is that emails are typically intended for those the message has been sent to and not for broad distribution - they can contain sensitive content that would cause harm if broadly distributed (e.g. server names, passwords, financial data, etc.) Media on the other hand, is intended for broad distribution but only after you've purchased a 'license' to use it.