Be direct and to the point and, in the first sentence, acknowledge the receipt of their letter of resignation and formally accept it. Resignation Acceptance Email templates: Discover how to write an effective resignation acceptance letter.In the US I would say it's not safe, at least not entirely. That's communication with your prior employer usually from the email address they provided. The purpose of the letter is to keep in your file to prove 1) you resigned and weren't fired. 2) You gave the proper notice. Resignation letter is a notice, not a request. It's not something they can reject. Learn how to write a short notice resignation letter with samples. Find a solution to the challenge of resigning on short notice.