I am writing this correspondence to inform you of my immediate resignation as Executive Assistant to the President at Company Name. I’m afraid that, due to unforeseen circumstances, I am unable to give proper notice and must let you know that my last day of employment will be tomorrow, September 19, 2014. Please accept this letter as my official resignation from my position.
It is my intention to work the entire day tomorrow to finish outstanding projects and to clean out my office. The University President has already been informed of my resignation and is aware that tomorrow will be my last day. I can be reached at 000-000-0000 or at email@example.com should you require further assistance or have any questions. I will get back to you as quickly as possible.
While I regret that I must resign immediately, I have enjoyed working at Company Name for the past four years and have gained invaluable experience. I wish you and my colleagues well in your future endeavors and thank you for your prompt attention to this matter.