The answer is email. Allow me to elucidate.
All of us read. I can say that because if you can’t read, then you aren’t reading this, and you aren’t among the ‘us’ I refer to. Most of us have read a number of books, including some that were written in the not-so-recent past. And I’m sure most of us have noticed that in old books, the syntax and spelling of words in can be different than those we are accustomed to. The degree of differentiation varies based upon the culture and times of the author of the book in question. What does this tell us? Language evolves, it grows, it mutates. E-mail may have been correct at one time, but it is no longer.