Automatic newsletter to mailchimp optin list

Hello,

I'm trying to find a way for my client to send newsletters/emails from the wp dashboard to a mailchimp list that signs up using an optin form on the home page of the site.

I know I can use the Mailchimp plugin to capture the optins and I can use the e-newsletter plugin to create and send the newsletters but the optin list has to be added manually and I want it to work automatically.

Is there a way to do this?

Thank you
Craig