Does it redirect to the success page? It could be that the to address recordset isn't returning a value. I'd probably var_dump() the email object to try to diagnose what the issue is like:
$Email->send($emailGroup);
var_dump($Email);
die();
Then you can see if it has a TO address and if there are any issues with the body. If that all looks right then your email server may be rejecting emails FROM the from address you have set.