It has been 25 years since the invention of e-mail. Everybody I know uses it. They use it alot. Their use is self described as critical to their business and important to their personal lives.
Too many people get too much e-mail they can't ignore, organize, protect or trust. It has become as much of a distraction as it has an aid to communication. There must be billions of dollars wasted on it. And it's free!
E-mail can easily get sent by an imposter:
It can be sent anonymously via hundreds of free e-mail services. If you don't understand how it works it can be a vector for much mischief. Attachments grow like weeds unseen and clog file systems, exhausting backup capacity.
So much more can be said, I ought to write a book! The E-Mail Trainwreck. (Tom Lapp contributed to these ideas.)