Have tried out your page on my own servers. It validates as it should (although I am missing some of your CSS) - and it goes to thankyou page and returns form info in an email to me.
That doesn't mean that that was your problem, but I reattach your file with duplicate validations removed.
You could also try a simple test to see if php mail will send from your server - see Danni's post here.
What's a bit odd about the form working from my sever, is that I still have it set to your globals (in webassist/email/waue_contactus_1.php) as:
$MailFrom = "firstname.lastname@example.org"; (for 'From')
$WA_MailObject = WAUE_Definition("smtp.secureserver.net","25","","","",""); (For SMTP and Port - my server is Virtualnames and would not recognise smtp.secureserver.net). However the form info sends in the email fine.
I set these through the Universal Email Server Behaviour GUI.