In an age that demands instant gratification, emails have replaced letters, and more is the pity. In letters we used to go into depths; now we skim the surface of things in order to finish and move on quickly.
If we want to include details, we attach a picture or even a video. We communicate by email and replies to questions are generally brief. Compared to letters, emails are little more than an exchange of notes.
For the most part, letter writing has fallen by the wayside, and with it grammar: no more capitalisation of words - you know, those capital letters that make all the difference between helping your Uncle Jack off a horse and helping your uncle jack off a horse - and no more punctuation either which turns everyone into a psycho - e.g. "I like cooking my family and my pets" - or may cost you $13 million, see here.
Letter writing is an art which takes time. You sit down with a blank sheet of paper and pour out your thoughts. There is a sense of gravitas to it, a deliberate act of communicating with someone else whom you can almost image to be talking to as you write. You choose not just your words deliberately, but also your writing-paper, even your writing tool. I still treasure my Montblanc fountain pen - remember fountain pens? there was a time when a man was judged by the fountain pen he kept - with which I carried on many years of correspondence with some of the most important persons in my life.
Unfortunately, I didn't keep their letters. I always thought there would be another one but now there are only emails - and who wants to keep an email?