it takes a little tracking to find the template a page uses.
go to code view, then open the server behaviors panel. in the server behaviors panel, select the UE server behavior. this will highlight the UE code.
in the highlighted code, look for a line that starts with:
go to the webassist/email folder and open the file from the include line.
in that file look for a line that starts with:
$MailBody = $MailBody . (GetFromPage("
$MailBody = $MailBody . (GetFromPage("templates/templates_17.php"));
this tels you that the template used for that UE instance is webassist/email/templates/templates_17.php