adding a for element to the page will not work.
the server file name binding code needs to be added to the email body.
In Universal Email, did you select to use a template for the email message?
If so, you need to copy the server file name binding code:
File 1: <?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]; ?><br />
File 2: <?php echo $WA_DFP_UploadStatus["WA_UploadResult2"]["serverFileName"]; ?><br />
into the email template file where the file name should be displayed.