Sending email when you are angry, agitated, or upset is never a good idea. It might seem like a good idea at the time but I have never heard of a flame mail that was sent that ended up being positive. It simply is not productive. Find another way to get it out of your system that is more productive. You might want to call a friend to vent, especially one who is not involved in the immediate situation. If no one is available, take a break. Maybe take a walk to calm down. Fresh air and exercise work wonders. You might even want to write down some of the points that you want to discuss at a future date. Then sleep on it. Funny but when you wake up, the issue is never as big as it was the day before and you now can either calmly and rationally address the situation at hand or let it pass altogether.