@permastakemarke When you say automatic, do you mean on a nightly or regular interval? Or do you simply want each new customer to be added to a spreadsheet as they are added?
This is an accepted solution.
So you can easily export your customer list from Shopify in CSV format (Go to Customers and look for export along the top) or use a connector like ShopSync with Mailchimp or Klaviyo to send emails directly from those tools.
Hope this helps, if it does it would be awesome if you could select this as the answer to this post!