Do not copy a message or an attachment belonging to another person without permission. Example- Hello can I copy your attachment.
Do not forward chain letters.
Try to keep your sentences to a maximum of 15-20 words. Why-so you do not use two pages and people might not read it if you have to many words.
You are confirming that your email is live when you reply to spam.
It is important to add disclaimers to your internal and external mails.
If you write in CAPITALS IT SEEMS AS IF YOU ARE SHOUTING.
Do not make an email longer then it needs to be.
In business emails try not to use abbreviations.