Here is a common advice: don’t send emails when you are angry. You will regret it later once you are calm and had some time to think about it. The problem is that when we are mad, we can’t really control the urge of sending this mail and tell those corporate goons/our boss/our spouse what we think of them. When we are mad, we want revenge and email is the nerd’s machine gun… 

With all the improvements in artificial intelligent someone should come up with a service that analyze your outgoing emails for the relative level of anger and blame (can be adapted to the user as the system trains itself). If an email crosses a threshold it will display following message: “I’ve analyze your email and it seems to be coming out of anger. I will hold the email for you and send it back in 24 hours for your review and edits”

In 9/10 of the cases, you will be calm by them and even if you still want to send this email, you will edit it in a way it helps your cause, rather than insulting the other.

Just think of how many people will not get fired/burn corporate bridges or lose a friend. So who is willing to build this service?