phpの変数では大文字と小文字が区別されます。 whileループを次のように置き換えてください:
while ($rows = mysql_fetch_array($query)):
$name = $rows['Name'];
$address = $rows['Address'];
$email = $rows['Email'];
$subject = $rows['Subject'];
$comment = $rows['Comment']
echo "$name<br>$address<br>$email<br>$subject<br>$comment<br><br>";
endwhile;