Sure, it may sit in the depths of HR until the end of time, but you can be sure of two things: One, your former boss (and future reference) will read it and be impressed. And two, if you ever decide to come back to your company (hey, it happens), it's a very good thing that last thing on file is a great, professionally written resignation letter.
How to write an excellent resignation letter. Whatever the language, the sentiment is the same: I'm outta here. However, as a professional person, you need to express that maturely and firmly__ideally, one that doesn't alienate anyone at the job you're leaving. I'm sure we all have that fantasy where we tell off everyone who wronged us on the way out the door, but that person in the fantasy/movie/TV show never seems to have to live with the consequences afterward.