How to write a resignation letter that's effective immediately? Professional resignation letter examples for different reasons.Free templates and writing guide to resign on a positive note without feeling awkward. Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. It's polite but not necessary for your resignation to go to your manager. It can go straight to HR. It has to be in writing, but email is in writing. Learn how to craft a professional resignation letter without notice with our guide.