The Mailchimp integration works right out of the box with Yieldify. To integrate, simply go to the Settings page of the platform and hit Connect. You'll then be presented with an authorisation screen:

Once you've granted the platform access to Mailchimp, you'll be redirected back to the Settings page. You'll then need to input a mailing list identifier so that any leads collected can be sent to the correct location.

You can find this in Mailchimp (where it's referred to as an Audience ID) by going to Audience > All Contacts > Selecting the List you want from the dropdown > Settings Dropdown > Audience Name & Defaults.

The Audience ID can then be found where the blue square is: