Send HTML Email in PHP

ini_set("SMTP","[YOUR-EMAIL-SERVER-ADDRESS]");  // this line 184 for me  

$to      = '[YOUR-TO-EMAIL-ACCOUNT]';
$subject = 'This is the subject line';
$message = '
Hello World!
';
$message .='';
 
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=iso-8859-1" . "\r\n";

$headers .= 'From: <from@example.com>' . "\r\n";
$headers .= 'Cc: cc@example.com' . "\r\n";

mail($to, $subject, $message, $headers);