You think you know how to send and reply to email? This article is from Matt Might, Assistant Professor at the University of Utah, USA.
The problem with email is that people think it’s electronic mail. Email is not mail in electronic form. You are not writing a letter. Few send readable email or tap the deliberative potential of the medium. For example, email should be formatted into points – not paragraphs.
And, you should not always reply above the message you were sent. Many of these tips are already widely followed in academia, where debate and discussion over email have been taking place for decades.
Do It And How 