/**
  * @param Array $messageIndexSet
  * @param bool $indexAsUid
  * @param Folder $fromFolder
  * @param Folder $toFolder
  * @return bool
  */
 function CopyMessages(&$messageIndexSet, $indexAsUid, &$fromFolder, &$toFolder)
 {
     $messageIndexes = implode(',', $messageIndexSet);
     if ($this->_imapMail->select_mailbox($fromFolder->FullName)) {
         if ($indexAsUid) {
             return $this->_imapMail->uid_copy_mail($messageIndexes, $toFolder->FullName);
         } else {
             return $this->_imapMail->copy_mail($messageIndexes, $toFolder->FullName);
         }
     }
     return false;
 }