If you could help me follow the idea further: In my mind, a communication is mine until I send it, at which point it is my property in the trust of another, until delivered to whom I'm communicating with, at which point it becomes their property.
I know legal reasoning doesn't always follow what I may consider to be common sense- can you shine any light on what I'm missing?
(Prefer not to focus on the DHL/UPS etc side of things, because I understand their right to snoop is a part of their TOS.)