It is likely that our system is incorrectly identifying your domain as a GoDaddy domain, even though it is not registered directly with GoDaddy. However, that shouldn't stop you from being able to connect your domain manually. You'll need to login to your domain manager and update the "A" record to 22.214.171.124 and your "cname" record to shops.myshopify.com. You can find more detailed information on the terminology and what to tell your domain provider through our help document here. As for Mailchimp, that may be something you want to reach out to Mailchimp about once you have your domain connected to your Shopify admin as they'll likely have specific instructions on how to get your email setup.
Let me know if you have any questions!