WordPress Registeration problem

Hello Guys,

I am a wordpress fan from past 6 years and donated many themes to wordpress community.

But I still found many things lacking in wordpress for building out a perfect website using core wordpress.

I am trying to make a “Registration form” for one of my own websites. I have created one custom form using these tutorials on internet but eventually I landed up getting hell of spam on registration and have to implement Captcha on the same.

I tried Various captcha plugins also tried building captcha of my own. But Spammers bypassed them too.

Now a last hope i have is having a double layer security of having “User activation via validation link sent in email” and “Manual approval of user after activation”

I have searched over internet and wordpress forums for the same but landed up having no satisfiable results in my hand.

I have achieved a manual user approval by admin in my back-end. But that will not stop spam as per my thinking.

I would like to know how to achieve “User activation link to be sent to email” after registration.

Please let me know about some example plugins or manual methods.

Awaiting your responses,

Thanks in advance,
Sam