In the Create Email Message behavior, if you select the option to create a file for the email message, a template file is created for the email and it automatically includes all of the form elements in the email.
you can edit that template file to change how the email looks, and you can exclude form elements from the email by editing the removeBegins array, by default it will look like this in the email template:
$removeBegins = array();
$removeBegins = "Security";
you can add the beginning of other form elements name to the array to have them removed as well. the template file will be in the webassist/email/templates folder.