Rooster has a native integration with Mailchimp allowing you to easily build email auto-responders or newsletters for visitors recaptured via Rooster.
In order to integrate with Mailchimp you'll need the following information:
Mailchimp API Key
Mailchimp List Id
Once an engagement overlay is integrated with Mailchimp Rooster will subscribe every recaptured visitor to your list. To help you provide custom content in your emails Rooster will also send Mailchimp all the information about the visitor you've collected in your Rooster form