I am a flincher. When someone raises their voice, my instinct is to immediately apologize and offer them my wallet. But conflict is unavoidable, unless you plan to live in a cave, and even then, you'll probably argue with a bat. The trick isn't to stop flinching. The trick is to flinch, panic for exactly three seconds, and then say what needs to be said anyway. Courage isn't the absence of fear; it's being terrified and still sending the email.