It is funny that this has come up. I collect old books and I was reading through an old turn of the century (early 1900's) book on ettiquette. The section on communicating applied to present day due to the changes in the way we communicate. In the 1900's, we communicated by writing mostly and we received our news by reading. Delivering of information went from the written word, to sound (radio) to images (Movietone News then the Television) to the internet where we have a mixture, but mostly reading. 

Communication changed from writing (letters) to verbal (phone) back to writing (e-mail)... those rules for writing from the 1900's apply today as well as it did then. The problem is, letter writing is a skill that takes practice and many of us fall into the bad habit of writing the way we talk. Sometimes, that does not come across as intended and that leads to all sorts of issues. 

ratscloset
aka John