How to write a resignation letter that's effective immediately? This case was specifically focused on the effect of the question of whether an employee had resigned would have on her entitlement to unemployment benefits.My resignation is effective immediately. You should never sign a resignation letter under duress. Employers may also want to consider the impact an immediate separation would have on remaining employees. After the meeting, provide the formal written notice to the manager via email or letter. Here is a sample template to craft a resignation email:. What is a No Notice Resignation Letter?