Abraham Lincoln was really angry at one of his generals once. The general had made a terrible blunder and Lincoln was set to give this general a good tongue lashing about it. Lincoln decided to put this one in writing. And boy, did he ever.
It was found in Abraham Lincoln's office desk after his death, never sent to the general.
Lincoln was practicing restraint in a wise way: saying what he needed to say, just not to anyone so as to not burn any bridges. The general probably already knew he had messed up, and Lincoln knew his vitriol wouldn't help matters at all.
I know I've let my anger out at people in unproductive ways. Anger makes people uncomfortable. Uncontrolled rage belies a lack of self-control. It can even destroy relationships. I've seen angry outbursts do all 3, sometimes all at once.
"Anger makes people uncomfortable. Uncontrolled rage belies a lack of self-control. It can even destroy relationships." 
Napoleon Hill advised angry people to write angry letters too - in the sand on the beach, by the water's edge. Right where the next wave can wash it away. Here are 4 tips for writing curbing your anger when you least want to, but most need to.
Place a space between stimulus and response. This is also known as maturity. Six-year old kids and wild animals react to things without thinking and are solely focused on themselves. You as an adult, need to be at a higher level of thinking.
Be angry alone. Scream at people. Cuss them out and really let them have it - in your car alone, with the windows rolled up. Write it down and never send it out. Write it in the sand.
Remember: Like attracts like. Positive energy create more positive energy. Negative energy attracts its kind as well. No matter how much you feel the other party deserves it, whatever you send out, you're bringing on yourself.
Value relationships over your (temporary) personal satisfaction. Letting your anger out at others may make you feel good for the moment. But the lost goodwill, damaged relationships and embarrassment (yours and theirs) you create are a high price to pay. Always think before you react.
[dt_quote type="blockquote" font_size="big" animation="none" background="plain"]The People Skills Course will help you build the skills necessary to create a nurture a network.[/dt_quote]