Automatically subscribe users to MailChimp list? I would like to automatically subscribe all newly registered users to a MailChimp mailing list.
Install the MailChimp Subscribe plugin and add the following users.onActivateUser event listener to your site’s Business Logic plugin.

craft()-&gt;on('users.onActivateUser', function(Event $event) {
    $user = $event-&gt;params['user'];

    if (!$user-&gt;admin) {
        $result = craft()-&gt;mailchimpSubscribe-&gt;subscribe($user-&gt;email, '');

        if (!$result['success']) {
            Craft::log('Couldn’d subscribe to MailChimp list: '.print_r([
                'errorCode' =&gt; $result['errorCode'],
                'message' =&gt; $result['message'],
            ], true), LogLevel::Error);
        }
    }
});