Body of the letter is usually divided into three paragraphs. However, you could add on more paragraphs as well, but minimum is three.
The first paragraph is the introduction paragraph. You introduce yourself and the purpose of your letter. The words that you use should strike a connection with the reader. Make sure you use simple form of language, nothing too fancy as such.
The second paragraph should cover the details related to the purpose behind the letter being written.
The last paragraph as such should sound pleasing. You should thank the reader for taking out time and looking into the letter.