You're thinking of this in the completely wrong way. Why should email - the protocol - offer you all of this? It's nonsense, and goes against basic UNIX philosophy (do one thing). It does another part of the UNIX philosophy very well, though: it's a universal interface. Email can be used to communicate between all sorts of applications, and those applications can give you the features you want easily. Which brings us back to what you're complaints amount to: client problems.