Hi,
The first argument to this function is the recipient, the second specifies the message's subject and the third one should contain the body. So to send a simple sample message, we could use:

<?php
$to = "recipient@example.com";
$subject = "Hi!";
$body = "Hi,\n\nHow are you?";
if (mail($to, $subject, $body)) {
echo("<p>Message successfully sent!</p>");
} else {
echo("<p>Message delivery failed...</p>");
}
?>