- Change your settings so that email from you has a name, your name, not a blank or some unusual characters, in the from field. (ask a geek or IT person for help if you don't know how).
- Change your settings so that the bottom of every email includes a signature (often called a sig) that includes your name and your organization.
- Change your settings so that when you reply to a note, the note you're replying to is included below what you write (this is called quoting).
- Don't hit reply all. Just don't. Okay, you can, but read this first.
- You can't recall an email you didn't mean to send. Some software makes you think you can, but you can't. Not reliably.
- Email lives forever, is easy to spread and can easily show up in discovery for a lawsuit.
- Please don't ask me to save a tree by not printing your email. It doesn't work, it just annoys the trees.
- Send yourself some email at a friend's computer. Read it. Are the fonts too big or too small? Does it look like a standard email? If it doesn't look like a standard, does this deviation help you or hurt you? Sometimes, fitting in makes sense, no?
And a bonus tip from Cory Doctorow (who got it from danah boyd). Cory gets more email than you and me combined: When you go on vacation, set up an autoreply that says, "I'm on vacation until x/x/2010. When I get back, I'm going to delete all the email that arrived while I was gone, so if this note is important, please send it to me again after that date."