using "if($_POST)" is not a very reliable way to check if the form was posted.
$_POST is a supper global that contains an array of the posted elements. it exists whether a form is posted or not. If a form was not posted, it's an empty array, but it still exists. "if($_POST)" will pretty much always return true.
as a test, put the following on a blank page:
<?php echo($_POST); ?>
this will return:
Array
to test for a form post use "if($_SERVER["REQUEST_METHOD"] == "POST")" instead
so the elseif statement at line 210 becomes:
elseif ($_SERVER["REQUEST_METHOD"] == "POST" && !$mailSent) {
If that doesn't help the issue, then please send a copy of the CSSMenuWriter/cssmw0/menu.php so I can examine the code.