sending multiple recipients email using smtp on PHP

Question

I am really need your help,

I am trying sending multiple recipients email using smtp email on php, can you help me please? check my code out

if($_SERVER["REQUEST_METHOD"] == "GET"):
    $to = "[email protected], [email protected]";
    $cc = "[email protected]";
    $from = "[email protected]";
    $subject = "Daftar PR Karet";
    $body = "
Berikut data PR karet pada tanggal $now :

$y

Note : pesan ini digenerate oleh computer.
Terima Kasih,
            ";
    $SMTPMail = new SMTPClient ($SmtpServer, $SmtpPort, $SmtpUser, $SmtpPass, $from, $to, $cc, $subject, $body);
    $SMTPChat = $SMTPMail->SendMail();
endif;

but it wouldn't send, it'll send if I remove the secondary $to email, instead...