Horde_Kolab_Storage_Driver::expunge PHP Method

    public function expunge($folder);

 /**
  * Delete the specified messages from this folder.
  *
  * @param array|string $uids Backend id(s) of the message to be deleted.
  */
 public function deleteBackendIds($uids)
 {
     if (!is_array($uids)) {
         $uids = array($uids);
     }
     $this->_driver->deleteMessages($this->_folder->getPath(), $uids);
     $this->_driver->expunge($this->_folder->getPath());
 }