“Netiquette” is slang for “Internet etiquette”. It refers to the accepted behaviors and practices regarding interactive online activity such as discussion forums, chat rooms, and e-mail. Your adherence to these guidelines will help make the online community in which you are participating easier and more enjoyable for everyone to use.

http://www.simplehelp.net/2006/08/14...od-netiquette/

Everybody who uses the internet should read that article! Especially the e-mail portion.