how to send muliple emails in drupal in same time

in my site when user submit a dination i want to send email to donor,charity and delivery service at same time(three different emails) in code and i want to kown how can i achieve that,below is the my mail seding function,i already tried call email function with 3 times with different keys for $key but that time emails are sending with out body content

 function zgRequestsdonor2_mail ($key, &$message, $params) {
  switch ($key) {
  case 'aftersubmit_donor':
    // Set headers etc

    $message['subject'] = t('email to donor');
    //$message['body'][] = t('Hello @username,', array('@username' => $params['username']));
    $message['body'][] = 'tyrtyrtyrtyty';
    break;
  }
}

calling it at

function zgRequestsdonor2_form_submit($form, &$form_state) {
  drupal_mail('zgRequestsdonor2','aftersubmit_donor',$donoremail, $language, $params = array(), $from = NULL, $send = TRUE);
}