All the tech tricks to try and figure out who gave who my email address are pointless exercises in time-wasting. Adding various words to your email (like with Gmail aliases) does no good because anyone can figure out your real original email. Only machines are (somewhat) fooled by this.
Of course, if you owned your own domain, or paid for quality email, you could have many multiple email addresses to partially address this, but since everyone switched over to so-called free email with social graph companies, what's the point.
Email will never die. Why should it? It's fast (instant, nearly) and you can send nearly anything to anyone - limited only by size (and with a few tricks, not even limited there). It's worldwide (not limited by who's on what 'network' or what is popular in whatever country).
If anything, I think we are seeing (or will see) a resurgence of email as the 'de facto' way of contacting and communicating with people. It even holds up pretty well in court. Email newsletters have made a come-back (a little bit) and with the stagnation of FB and G+ (did it ever grow?) and Twitter on the verge of Ch 11, how will you communicate with others? How will companies reach you?
Or did you want a fax machine?
