1.Don't over use reply all only use reply all if you really need the message that you sent be seem by all the people that you sent it to.
2.Don't send or forward emails that have libelous, defamatory, offensive and obscene remarks just by forwarding one libelous you can be get in serious trouble.
3.Don't text speak when you are writing an email don't talk like of you were texting with your friend ( lol, omg, ttyl, etc.) because the person you are writing an email to might not now what you are trying to say.
4.Always include your name it's a good habit because you might need it for collage courses also because if you don't include your name the person might not know who it is from.
5.Always use(CUPS)capitalization, usage, punctuation, and spelling it is important to use proper grammar because if you don't than the person that gets the email wont know where the sentence starts and finishes and you should always try to spell words correctly.