How to have Wordpress send a user confirmation/validation email on signup

Question

I have a WP 3.3 installed and running great. My client would like to confirm a valid email address by sending the user a confirmation email containing a link to "confirm". I have played around with Pie Register a little bit but cannot get it to send emails like it says it can.

Are there other plugins or tools out there capable of the same thing? I don't think its a huge deal but the client won't budge on it.

Also the site sends other emails just fine.

ideas?