I added code to write the session to the page, then tested.
it is submiting the form fine form me, and writing the email log to the page as:
string(61) "Sending To: firstname.lastname@example.org... Success
so it is saying that the email is being transferred to the SMTP server.
if you are not receiving the email, then the SMTP Server is not relaying it to you for some reason.
double check that the from address is a valid email address for your domain and that the SMTP server are correct for your host.