Never send an email when you are angry; you will most likely regret it later. Instead, when you are emotional and want to reply to someone, open up an email and write everything you feel, but do not send it. (Be sure there is no name in the TO field so that you do not accidently send it.) After you have vented, save the email and come back an hour later. You only want to reply to any type of emotional situation after you have had time to cool down.

https://securingthehuman.sans.org/u/lfx