Answered Trouble using Post Hooks with Login plugin - unable to receive email.

[[!Register?
    &submitVar=`registerbtn`
    &activationResourceId=`19`
    &activationEmailTpl=`lgnActivateEmailTpl`
    &activationEmailSubject=`Thanks for Registering!`
    &submittedResourceId=`23`
    &usergroups=`2`
    &postHooks=`adminEmailHook`
    &validate=`nospam:blank,
    username:required:minLength=^6^,
    password:required:minLength=^6^,
    password_confirm:password_confirm=^password^,
    fullname:required,
    email:required:email`
]]

<?php
$message = 'Hi, a new User signed up: '.$hook->getValue('username')
 . ' with email '.$hook->getValue('email').'. To activate this User please login to the ModX Manager and navigate to the Users menu under the Manage drop down menu.';
$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,'Company');
$modx->mail->set(modMail::MAIL_SENDER,'Company');
$modx->mail->set(modMail::MAIL_SUBJECT,'New User Signed Up');
$modx->mail->address('to','[email protected]');
$modx->mail->setHTML(true);
if (!$modx->mail->send()) {
    $modx->log(modX::LOG_LEVEL_ERROR,'An error occurred while trying to send the new user alert email: '.$err);
}
$modx->mail->reset();
/* tell our snippet we're good and can continue */
return true;

$modx->mail->set(modMail::MAIL_FROM,'[email protected]');