/* open [message_id].eml file for writing */
(void)string_format(mbox_path, 1024, "%s/scan/%s/%s.eml", spool_directory, message_id, message_id);
/* open [message_id].eml file for writing */
(void)string_format(mbox_path, 1024, "%s/scan/%s/%s.eml", spool_directory, message_id, message_id);