Why does modPHPMailer doesn´t work?

<?php
$message = 'Hello';
 
$modx->getService('mail', 'mail.modPHPMailer');
$modx->mail->set(modMail::MAIL_BODY,$message);
$modx->mail->set(modMail::MAIL_FROM,'[email protected]');
$modx->mail->set(modMail::MAIL_FROM_NAME,'MyDomain');
$modx->mail->set(modMail::MAIL_SENDER,'MyDomain');
$modx->mail->set(modMail::MAIL_SUBJECT,'New User Signed Up');
$modx->mail->address('to','[email protected]');
$modx->mail->setHTML(true);
if (!$modx->mail->send()) {
    $modx->log(modX::LOG_LEVEL_ERROR,'An error occurred while trying to send the email: '.$err);
}
$modx->mail->reset();
/* tell our snippet we're good and can continue */
return true;