PHPmailer - Beberapa pengiriman email

Setelah Anda mengirim email $mail->Send() , jalankan ini:

$mail->ClearAllRecipients();

di loop sementara Anda.
Jadi struktur perulangan while dasar Anda terlihat seperti ini:

while($row = mysql_fetch_assoc($p_address)){

    $mail->AddAddress($row['email_address']);
    $mail->AddAttachment("fpdf/pdf_reports/document/".$ctrl_no.".pdf");
    $mail->send();
    $mail->ClearAllRecipients(); 
    $mail->ClearAttachments();   //Remove all attachements

}