Create User Programmatically - Email Not Sent

[robogram]

I'm attempting create a user programmatically for the purpose of integrating my shopping cart software to vBulletin. The problem I'm having is that my code creates a new user but doesn't send the email specified in the code. I suspect there is some combination of settings that I don't have quite right - can you help? I'm not finding much in the way of documentation on vbmail - is there a better way?

<?php
define('THIS_SCRIPT', 'register');
define('VB_AREA', 'External');
define('SKIP_SESSIONCREATE', 1);
define('SKIP_USERINFO', 1);
define('CWD', '../forum');
require_once(CWD . '/includes/init.php');
// init user datamanager class
$userdata =& datamanager_init('User', $vbulletin, ERRTYPE_ARRAY);

// check for matching email addresses
if ($vbulletin->GPC['email'] != $vbulletin->GPC['emailconfirm'])
{
$userdata->error('emailmismatch');
}
// set email, username & usergroup
$userdata->set('username', 'bjones');
$userdata->set('email', 'bjones@gmail.com');
$userdata->set('password', 'verysecret');
$userdata->set('usergroupid', 2);
$userdata->pre_save();

// check for errors
if (!empty($userdata->errors))
{
$errorlist = '';
foreach ($userdata->errors AS $index => $error)
{
$errorlist .= "<li>$error</li>";
}

// ... additional code; $errorlist is outputted to the user
$username = htmlspecialchars_uni($vbulletin->GPC['username']);
$email = htmlspecialchars_uni($vbulletin->GPC['email']);
$password = htmlspecialchars_uni($vbulletin->GPC['password']);
$show['errors'] = true;

}
else
{
$show['errors'] = false;

// save the data
$vbulletin->userinfo['userid']
= $userid
= $userdata->save();

// send new user email

require_once(DIR . '/includes/functions.php');
$userinfo = fetch_userinfo($userid);
$username = $vbulletin->GPC['username'];
$email = $vbulletin->GPC['email'];

eval(fetch_email_phrases('welcomemail'));
vbmail($email, $username, $subject, $message);

}
?>

Thanks - Robogram