"Dear (manager's name),
I hereby tender my resignation from my role as marketing manager of X,Y,Z company. My resignation is effective
As per my contract, I am providing X,Y,Z with X weeks notice. My last working day will be (fill in the date).
Your name , surname
Position held in company
Depending on your personal feelings, you might want to that you have valued your time with the employer, learnt a lot, made friends and enjoyed yourself. Otherwise say nothing else.
This Italki site will help you further