Here's another picture of the future, from 1979. I found these on the site Paleofuture, by the way. Although I think I did had this book as a kid.
There's a flat screen TV which is used to order shopping. There's a video disc player that can record TV. And the mail slot is number 6 -- this is what it says in the caption:
"By 1990, most mail will be sent in electronic form. Posting a letter will consist of placing it in front of a copier in your home or at the post office. The electronic read-out will be flashed up to a satellite"
So there's no postal service and there's electronic mail... but still paper and keyboards. So close!
Source: Paleofuture I think...
Matt Webb, Web Directions South 2014 (Sydney, Australia), October 2014