Did you notice that there are two parts to the plugin? This part:

<?php
if ($mode == modSystemEvent::MODE_UPD) {
    if ( ! $user->get('active') && $_POST['active'] ) { 
        $modx->logManagerAction('activate_user','modUser',$user->get('id'));
        $email = $_POST['email']; 
        /* Code to Send email goes here */
    }
}

And the part that sends the email (which gets pasted exactly where the comment is)? I pasted both from working code, although It’s possible that something has changed in newer releases of 2.x.

[[!Register? &submitVar=`registerbtn` &activationEmailTpl=`myRegistrationEmail` &activationEmailSubject=`Registration Submitted` &submittedResourceId=`17` &usergroups=`PrivateUserGroup` &postHooks=`hookNotifyAdminEmail` ]]

<p>Hi, [[+username]],</p>

<p>Thanks for registering! Your application will be reviewed. On acceptance you will receive a confirmation email with details of where to login.</p>
<p>The password you registered was <strong>[[+password]]</strong> and your username is <strong>[[+username]]</strong>. Please keep these safe as you will require them when you are approved for login.</p>

<p>Kind regards,

<em>Site Administrator</em></p>

<?php
if ($mode == modSystemEvent::MODE_UPD) {
if ( ! $user->get(’active’) && $_POST[’active’] ) {
$modx->logManagerAction(’activate_user’,’modUser’,$user->get(’id’));
$email = $_POST[’email’];
$name = $user->get(’username’);
$msg = "<p>Dear " . $name . ",</p>
<p>Thank you for registering at " . $modx->getOption(’site_name’,null,’My Site’) . ".</p>
<p>Your registration has been approved and you now access the Members area, please login <a href=’http://www.mywebsite.co.uk/login’>here</a>.</p>";
$msg .= "<p>Kind Regards,
Site Administrator</p>";
$subject = ’Registration Approved’;


$modx->getService(’mail’, ’mail.modPHPMailer’);
$modx->mail->set(modMail::MAIL_BODY, $msg);
$modx->mail->set(modMail::MAIL_FROM, $modx->getOption(’emailsender’));
$modx->mail->set(modMail::MAIL_FROM_NAME, $modx->getOption(’site_name’));
$modx->mail->set(modMail::MAIL_SENDER, $modx->getOption(’emailsender’));
$modx->mail->set(modMail::MAIL_SUBJECT, $subject);
$modx->mail->address(’to’, $email, $name);
$modx->mail->address(’no-reply-to’,’’);
$modx->mail->setHTML(true);
$sent = $modx->mail->send();
$modx->mail->reset();
}
}

Plugins are notoriously hard to debug unless you have a debugger that will let you set breakpoints in the plugin and launch the manager.

Try implementing it as a snippet first that’s triggered with a snippet tag on a regular page. Set the necessary variables in parameters or at the top of the snippet. Once it’s working, paste it to your plugin.

If you’re not sure about your email capabilities, download the new QuickEmail snippet to test them.