On the form page, what is the action of the form? the Universal Email behavior should be on the forms action page. if the form is set to post to the thank you page, look for the UE behavior on the thank you page.
Who is your host?
Depending on your host, you may need to set certain options in Universal Email.
Some hosts will work if you leave the SMTP Server setting on the Email Server Tab blank, others will require that you enter the SMTP server address.
Some will work using the standard Mail protocol, other will require that you use the Pear Mail for SMTP, some using Pear mail will require authentication.
Some hosts may require that the from address being used be a valid email address for your domain. Some may require that the option to include the from Email address be passed as an extra parameter.
To be successful with Universal Email, you will need to know the requirements of your host for sending an email using a PHP script.
Also, double check your Spam folder, it is possible that the email is being trapped as spam.