Electronic mail has been playing a more and more important role in human communication activities. This paper is aimed at exploring critical issues while using this new media. The author first presents the definition of E-Mail Etiquette, then introduces some common rules of sending and receiving e-mails. Skillfully utilizing smilies, intensifiers, and abbreviations are recommended in the cyberspace environment. The paper is wrapped up by expecting to rapidly develop a local e-mail etiquette, in order to bring this new communication media into full play.