1) Some of the Digital file Pro code was not copied from the from page to the processing page:
//WA_UploadResult1 Params Start
$WA_UploadResult1_Params = array();
$WA_UploadResult1_Params["WA_UploadResult1_1"] = array(
'UploadFolder' => "../uploads",
'FileName' => "[FileName]",
'DefaultFileName' => "",
'ResizeType' => "0",
'ResizeWidth' => "0",
'ResizeHeight' => "0",
'ResizeFillColor' => "" );
// WA_UploadResult1_1 End
// WA_UploadResult1 Params End
2) in the DFP Server behavior, you do not need to click the lightning bolt next to the File Filed, instead, you should select the name of the file field from the drop down list.
3) In the email, you should not refer to the file from the file collection, instead, expand the WA Digital File pro Uploaded Files group and select the Server File name.
instead of having the form post to another page, it is much simpler to have the form post to itself, and add the upload and email server behaviors to the same page, you dont have top copy from one page to another that way.