I don't see a problem with this page. Can I see a copy of the page: webassist/email/waue_membership-applicationwoo_1.php
Maybe it is where the issue is.
Are you on your live server when testing? What did you set as the FROM address? Are you sure it isn't sending but being placed in the SPAM folder?
One good way to test is to add a session dump to the page like:
That will let you check to see if the page settings are set to the values you would expect and if it "thinks" the email was sent correctly.