I need to write an email message directly to our CEO and board about the excessive overtime in our dept, need suggestions

So I am sick and tired of constantly on OT for 2-3 days per week and there are some rumors that we will have a weekend OT. Out Chief Tech Officer is a numb and ungrateful pos that doesn't care about our personal wellbeings, we have overtime pay but you cannot pay any amount the lost personal time we could have. I need some advice so that I can directly stake through the heart. I will write the email annonymously using disposable email