OK, thanks, that gives me something to go on.
The problem is the forms action.
You have the forms action set to post to another page.
All Form Processing MUST occur on the action page.
you should set the form action to post to the contactUs.php page so that the validation can occur, then the email can be sent. In the universal email behavior, you can can set the go to page to redirect to the confirmation.php after the email is sent.