<?php
$to    = 'site@mail.ru';
$theme = 'Site URL: ' . $modx->getOption('site_url');
$body  = 'Test mail message';
$from  = $modx->getOption('emailsender');

$modx->getService('mail', 'mail.modPHPMailer');
$modx->mail->address('to', $to);
$modx->mail->set(modMail::MAIL_FROM, $from);
$modx->mail->set(modMail::MAIL_FROM_NAME, 'Console');
$modx->mail->set(modMail::MAIL_SUBJECT, $theme);
$modx->mail->set(modMail::MAIL_BODY, $body);
$modx->mail->setHTML(true);
if (!$modx->mail->send()) {
    echo 'Sending failed. Error: ' . $modx->mail->mailer->ErrorInfo;
} else {
    echo 'Success';
}
$modx->mail->reset();