The average US employee spends about a quarter of the work week combing through the hundreds of emails we all send and receive every day.
But despite the fact that we're glued to our reply buttons, career coach Barbara Pachter says plenty of professionals still don't know how to use email appropriately. 
In fact, because of the sheer volume of messages we're reading and writing each day, we may be more prone to making embarrassing errors — and those mistakes can have serious professional consequences.
Pachter outlines the basics of modern email etiquette in her book "The Essentials Of Business Etiquette." We pulled out the most essential rules you need to know.
Vivian Giang and Rachel Sugar contributed to earlier versions of this art