Even if you're not close with your boss, chances are you have a working, first_name_basis relationship. Maintaining that in your official letter is okay. You don't need to keep a Victorian level of formality here__just make sure it's a professional tone.
What Should My Letter of Resignation Say?. If you're not sure of how to write a resignation letter, that's normal __ it's certainly not an everyday task. Take a look at a sample resignation letter, or a few if you want to explore different options. In our view, the shorter the resignation letter, the better.