You need to edit the email template page.
look in the UE Code block, there will be a line that attaches to the email setting file, similar to:
open that file. in that file there will be a line that attaches to the template file similar to:
$MailBody = $MailBody . (GetFromPage("templates/Blank.php"));
go to webassist/email/templates/ and open the template file to edit the email body.