can you describe in what way it does not work?
Does it not send the email?
Does it send the email incorrectly?
I will need a description of the results you are getting vs. what you expect to happen to be able to offer assistance.
If you could also send a copy of the page, that would be helpful.
if you are not receiving the email, you should double check that the email server is set correctly. Also try leaving the From Display Name option blank in the Email password server behavior.
If you are still having a problem, make sure that the If lookup fails option is set to go to a failure page, if the lookup fails it will not try to send an email, so determining if lookup is successful can help trouble shoot.
If it is going to the lookup failure page, make sure the setting fro the email column is correct.