The reason I'm asking is because my superior has a history of witholding employees resignation and then decides when they get to leave (maybe a few days later). But I do not want that. I have already organized all my plans and will leave exactly on the date that will be stated on my letter. Now, if I resign in person (more polite and giving them heads up) I run the risk of them pulling that on me. If I resign by email, I would have black and white.
They also have a history of not allowing employees to clear their remaining leaves during resignation which I find ridiculous.