Answered Send Message from Manager to Member on Front-end

<li><input type="checkbox" name="messages[]" value="[[+id]]"> [[+subject]] [[+message]]</li>

[[!ShowMessages? &tpl=`messageTpl` &outerTpl=`messageOuterTpl`]]

<?php
/* do nothing
 if user is not logged in */
if (!$modx->user->hasSessionContext('web')) {
    return '';
}

/* process form */

if (isset($_POST['submit'])) {
    if (isset($_POST['messages']) &&
 (!empty($_POST['messages']))) {
        foreach ($_POST['messages'] as $messageId) {
            $msg = $modx->getObject('modUserMessage', (int) $messageId);
          if ($msg) {
              $msg->remove();
          }
       }
    }
}

/* Display messages */
$tpl = $modx->getOption('tpl', $scriptProperties, 'missing Tpl');
$outerTpl = $modx->getOption('outerTpl', $scriptProperties, 'missing Tpl');
$uid = $modx->user->get('id');

$modx->getCollection('modUserMessage', array('recipient' => $uid));
$count = !empty($messages) ? count($messages) : '0';
$modx->setPlaceholder('messageCount', $count);
 
if (empty($messages)) {
    return '<h1>No Messages</h1>';
}

$output = $modx->getChunk($outerTpl);

foreach ($messages as $message) {
    $fields = $message->toArray();
    $inner .= $modx->getChunk($tpl, $fields);
}

$output = str_replace('[[+messages]]', $inner, $output);

return $output;