your recordset is set to filter on the orderID url variable, make sure this is included in the forms action:
<form action="ordersDetail.php?orderID=<?php echo(isset($_GET['orderID'])?$_GET['orderID']:""); ?>" name="shipEmail" method="post">
to show the order contents, add the repeat region for the order details recordset to the email template page and the bindings to show the columns from the order details recordset.