If you have this feature, use it. Late Nights Be especially careful about messages you compose late at night. 9PM or so, which makes us think we're typing in sensible messages, when in fact they are subject to severe misunderstanding. If it can, my advice is to save it in a file and look at it tomorrow morning. Chances are you'll want to make some changes to make it more clear and more polite.
Personal Remarks Making derogatory remarks about others is a bad idea.
Doing it behind their back is worse. Doing it in public is worse still. Electronic messages are the last place for any kind of uncomplimentary remark. Just don't do it. If you insist on posting a message or sending mail, make sure you do it the right way, use the correct mail class, and avoid spamming people.