SMPT not work

include_once($modx->config['base_path'].'manager/includes/controls/class.phpmailer.php');

$mail = new PHPMailer();

$mail->IsSMTP();                            // set mailer to use SMTP
$mail->Host = "smtp.mydomain.it";        // specify main and backup server
$mail->SMTPAuth = true;                        // turn on SMTP authentication
$mail->Username = "[email protected]";;    // SMTP username
$mail->Password = "mypassword";            // SMTP password

$mail->From = "[email protected]";    //do NOT fake header.
$mail->FromName = "MailMan";
$mail->AddAddress("[email protected]");
$mail->AddReplyTo("[email protected]", "Support and Help"); //optional

$mail->Subject = "Just a Test";
$mail->Body    = "Hello. I am testing PHP Mailer.";

if(!$mail->Send())
{
   echo $mail->ErrorInfo;
}else{
   echo "email was sent";
}