For years I've complained that email was too analogous to old-fashioned postal mail. People flocked to it because it was faster and cheaper than buying stamps. Unfortunately, folks still carried the same old mindset when using it. It seemed a chore for many to sit down as they assumed the message needed to be long and drawn out. Email was free so really all that was necessary was to jot out a sentence, or even just a word. Still behaviours seldom changed and lots of mail sat unanswered as folks couldn't find the time nor inclination to compose a long, "letter-like" response.
In recent years, Facebook and Twitter have taught people to think in shorter exchanges. Most don't associate them with private messaging though. Actually Google+ would an optimum replacement for email. It is easy to group people into circles and then write to a specific stream. It's much more intuiative than Facebook's privacy settings. Yet then, a more pronounced problem rears its ugly head; practically nobody I know uses Google+.
I was able to send a private message to the G+ stream of a friend last night. I had added some directions to a screen capture of Google Earth and uploaded it with comments. I put it into just his stream as we're expecting to meet up with him and his friends on the evening of Valentine's Day when we arrive in Puerto Vallarta. Doing this has added a permanence to the message as if posting on a Facebook's wall. It is saved so that we may both view it and even add to or edit it. This way of communicating seems much more logical than an email exchange.