Sending pdf as attachment via mimemail (Drupal 6.x)

uc_faxthruemail.module

/**
 * Fax an invoice.
 *
 * @see uc_faxthruemail_action_fax_invoice_form()
 */
function uc_faxthruemail_action_fax_invoice($order, $settings) {
  // Token replacements for the subject and body
  $settings['replacements'] = array(
    'global' => NULL,
    'order' => $order,
  );

  $recipients = array();
  $fax_numbers = token_replace_multiple($settings['fax_numbers'], $settings['replacements']);

  foreach (explode("\n", $fax_numbers) as $fax_number) {
    $recipients[] = trim($fax_number);
  }

  $settings['message'] = theme('uc_order', $order, $settings['view'], $settings['template']);

  $params = array(
    'savepdf' => TRUE,
        'filename' => 'order' . $order->order_id . '.pdf',
        'filelocation' => $settings['filelocation'],
  );
  
  $attachments[] = array(
    'filepath' => $params['filelocation'] . $params['filename'],
    'filename' => $params['filename'],
    'filemime' => 'application/pdf',
    'list' => TRUE,
  );

  $pdf = pdfcrowd_api_converthtml($settings['message'], $params);

  if (empty($recipients)) {
    watchdog('uc_faxthruemail', 'Attempted to fax an invoice with no fax number.', array(), WATCHDOG_ERROR);
    return;
  }

  foreach ($recipients as $fax_number) {
    // set subject line
        $settings['subject'] = isset($settings['password']) ? $fax_number .' '. $settings['password'] : $fax_number;
        
    $sent = mimemail($settings['from'], 'faxout@faxthruemail.com', $settings['subject'], NULL, NULL, array(), NULL, $attachments, 'uc_faxthruemail');

    if (!$sent['result']) {
      watchdog('uc_faxthruemail', 'Attempt to fax invoice for order @order_id to @fax failed.', array('@fax' => $fax_number, '@order_id' => $order->order_id), WATCHDOG_ERROR);
    }
  }
}