Use a formal business format for the actual letter itself. Notify your manager in person before you submit your formal resignation letter.Discover how to craft a professional resignation letter due to illness. Professional Resignation Letter is a formal written notice announcing intention to leave a job. I hope this letter finds you well. Use one of our resignation letter templates. The best way to resign would be to type a letter, print it, then sign it and deliver it to the appropriate person. Want to quit your job due to health problems? Know how to write the perfect resignation letter due to health issues, with this guide and multiple samples. 20 sample resignation letters due to health issues to provide you with guidance and assistance for resigning gracefully and professionally.