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.This letter accepts an employee's resignation, noting their last day will be after serving out their required notice period according to their contract. You must give at least a week's notice if you've been in your job for more than a month. Your contract will tell you whether you need to give notice in writing. I wish to inform you that your resignation has been accepted. Template for an employer to acknowledge an employee's resignation. What's the best way to calculate notice period in the UK? Find out now with our notice period calculator. Stick to the plan set out in the letter.