foreach ($fields as $key => $row)
{
    $tmp = 0;
    if ((int)$row['id_customer'] AND $row['id_customer'] != $customer->id AND $row['email'] != $from)
        continue;
    if ($row['id_order'] != 0 AND Tools::getValue('id_order') != $row['id_order'])
        continue;
    if ($row['email'] == $from)
        $tmp += 4;
    if ($row['id_contact'] == $id_contact)
        $tmp++;
    if (Tools::getValue('id_product') != 0 AND $row['id_product'] ==  Tools::getValue('id_product'))
        $tmp += 2;
    if ($tmp >= 5 AND $tmp >= $score)
    {
        $score = $tmp;
        $id_customer_thread = $row['id_customer_thread'];
    }
}