I feel like in American enlish people tend to chose present perfect instead of simple past,<br/><br/>to be more formal! Is it true? What do you think about it? For instance:<br/><br/>Thank you I have received your mail! (formal)<br/><br/>Thanks I received your mail! (informal)<br/><br/>or<br/><br/>The number you have dialed is incorrect! (formal)<br/><br/>The number you dialed is incorrect! (less formal)