That's really strange... we (italian) always use capital letter at the beginning of a sentence, and of course at the beginning of a letter, after a full stop, question or exclamation mark. We use capital letters for names of people or countries and cities, but not for adjective or other type of names. Anyway: Buongiorno caro Ronnie -> OK Caro Ronnie, Buongiorno -> NO Caro Ronnie, buongiorno -> OK and Tanti Auguri Ronnie -> NO Tanti auguri Ronnie -> OK Try to ask to that native italian speaker why he/she told you that. Maybe there's some other reason.