Due to unforeseen circumstances, I must resign. 18'h,2021 at p.m. EST.Use our free letter of resignation template to make drafting your letters easy or fill in your details and we'll create the letter for you free of charge! In this article, we discuss what to include in a professional resignation letter and we share examples of resignation letters you can use for reference. Date. Dear (Manager's name),. I am writing to officially tender my resignation from (Company name) effective (Date). Write a letter of resignation. It's up to you how detailed you want to make it. Date. Dear (Manager's name),. I am writing to officially tender my resignation from (Company name) effective (Date).