Please remember that people all over the world are reading your words. Do not attack people if you cannot persuade them with your presentation of the facts. Screaming, cursing, and abusing others only serves to make people think less of you and less willing to help you when you need it. If you are upset at something or someone, wait until you have had a chance to calm down and think about it. A cup of coffee or a good night's sleep works wonders on your perspective.
Hasty words create more problems than they solve.
Try not to say anything to others you would not say to them in person in a room full of people. Never say in ten words what you can say in fewer. Say it succinctly and it will have a greater impact. Remember that the longer you make your message, the fewer people will bother to read it. They may someday be your co-workers or friends.