More and more, however, developers have stopped banging their head against the wall replacing email's installed base, and have turned their attention to creating larger systems of which email is only a part. This is a much more productive approach, and has led to innovations both on the user side and on the server side.
On the user side, we have interesting startups such as InBoxCube, Slack, and MailTime. Making email's front end more productive and usable has attracted the attentions of the big players as well, giving us Google Inbox and Android for Work, Microsoft Delve and Clutter, Cisco Project Squared, and IBM Verse.
On the server side the innovation is quieter and behind the scenes. But there too, email is becoming a building block for new services and features. Particularly when built on the cloud, email back ends are streamlining or eliminating most email administration functions for many businesses. Security features continue to evolve, and while spam and virus filtering will always remain important, new features allow realtime evaluation of possibly dangerous links at the moment the user clicks on them in his email.
Mimecast is doing not only that, but also building up an enormous email archive for each client, which will serve as a powerful source of business intelligence. For example, implicit in a company's email archive is the knowledge of which employees speak which language. A simple application can help find appropriate translators quickly at the moment they are needed, rather than requiring a broadcast cry for help. I believe there will be hundreds of such applications built on top of consolidated email archives. Most users will never even realize that these business tools derive their power in large part from email.
It is even possible that some day, people will be unaware of consciously using email. Instead, they will use a variety of user interfaces, combining multiple communication modalities and geared to different usage patterns. But they'll be able to communicate seamlessly with other people who use other "non-email" systems, because they both use email underneath, as a lingua franca. Email could conceivably become as invisible to the user as TCP/IP itself. But just as modern email still has line limitations that derive from punch cards, and just as modern homes have "power bricks" attached to nearly every appliance instead of DC current in the walls, email has become a permanent part of the infrastructure that will underly and be used by any future and more modern-seeming communication tools.