wp_mail sends email twice inside function updated_postmeta

Remove foreach and directly add this code:

$client_infos = get_users($args);
if($client_infos)
{
    $client_email = $client_info[0]->user_email;
    $to = $client_email;
    $subject="Due diligence is Complete";
    $body = 'Lorem ipsum';
    wp_mail($to, $subject, $body);
}