CModule::IncludeModule("subscribe");
$arFields = Array(
	"RUB_ID"		=> array($arParams['ID_SUB']), // id рассылки должен быть массив!
	"USER_ID"		=> $USER->GetID(),
	"FORMAT"		=> "text",
	"EMAIL"			=> $USER->GetEmail(),
	"ACTIVE"		=> "Y",
	"SEND_CONFIRM"	=> 'N'
);
$ID = $subscr->Add($arFields);


$subscription = CSubscription::GetByEmail($USER->GetEmail());				
if($arSub = $subscription->Fetch()){		
	$arResult['DATA_SUB_USSER']	= $arSub;
}

// подтверждаем подписку
$res = $subscr->Update($ID, 
	array(
		"CONFIRMED"		=> "Y",
		"CONFIRM_CODE"	=> $arResult['DATA_SUB_USSER']["CONFIRM_CODE"]
	)
);