Configuring automatic data export to mailchimp
Go to the Site you want to configure data export for by clicking on the Site drop down menu in top right corner.
Once in site go to Settings by clicking the tab on left, and move to Exports section.
Select Export to mailchimp option and Save the settings.
Now click the Config button to open Mailchimp settings, configure each field as below. Don’t forget to Save the settings once you are done.
This can be found as part of your Mailchimp dashboard after logging in. For example in below case, server prefix is us13
Follow this mailchimp KB article to identify your List ID https://kb.mailchimp.com/lists/manage-contacts/find-your-list-id
You can generate an API key by going to your Profile page in mailchip and by clicking Extras option. https://kb.mailchimp.com/integrations/api-integrations/about-api-keys
Once all the configurations are saved, details of any new guest (Firstname,Lastname and Email) will be auto uploaded to Mailchimp.