The rules of email etiquette are not "rules" in the sense that I will come after you if you don't follow them. They are guidelines that help avoid mistakes (like offending someone when you don't mean to) and misunderstandings (like being offended when you're not meant to). These core rules of email etiquette help us communicate better via email.
(Updated July 2011)
Don't send anything you don't want to send.
"Reply" is good. "Reply to All" is better. Right?
Do not intimidate recipients with too much text.
Do you think quoting original text in your email replies perfectly is a lot of work? Don't let the '>' intimidate you! Here's a very comfortable, relaxed, quick and still clean and compatible way to reply properly.
Do you make these mistakes in your email subjects? (The key to getting your messages read is not to be clever.)
Forwarding emails is a great way of sharing ideas, but make sure the original idea is not hidden in obfuscation.
Not everybody can receive your fancily formatted emails. Some may even react furiously. To be safe rather than sorry, send plain text emails only when in doubt.
Email hoaxes often contain stories that are intriguing, and sure to irritate. Here's how to spot and stop urban legends.
Make sure you're not spreading worms and viruses via email or act as a vehicle for spreading spam. All this can be caused by malicious emails. Fortunately, there's protection.
More and better communication makes better relationships. Here's a way to spot and share relevant information and foster ties by forwarding emails and links.