well, "and it doest work" is a very broad statement.
Do you mean to say that it redirects to the success page, but never sends an email?
or that it redirects to the failure page when you enter an email address that exists in the database?
or that you are getting a php error message?
please be specific in what "and it doest work" means.
Also, are you testing locally or testing on the remote server?
If testing locally, it wont be able to send the email unless you install and configure an SMTP server.
If testing remotely, you will need to know the SMTP server email settings for your host, and will need to edit the setting on the email object tab to use the correct SMTP server.