you can use this
$xheaders = "";
$xheaders .= "From: Name-Here. <$email>\n";
$xheaders .= "X-Sender: <$email>\n";
$xheaders .= "X-Mailer: PHP\n"; // mailer
$xheaders .= "X-Priority: 1\n"; //1 Urgent Message, 3 Normal
$xheaders .= "Content-Type:text/html; charset=\"iso-8859-1\"\n";
$xheaders .= "Cc: [email protected]\n";
.................
mail($email3, $subject, $message, $xheaders);