public function MailGetSignatures($account_id)
 {
     // $account_id  : IDType (mail account ID)
     $this->CheckAndSetHeader(__FUNCTION__);
     $reg_args["account_id"] = $account_id;
     $this->encodeString($reg_args);
     $results = parent::MailGetSignatures($reg_args);
     $this->methodClose();
     return $this->RetvalConvertArray($results->signature);
 }