Update August 2020 - Direct Mailchimp syncing is now available
Here's a quick way to import your new customers to your email newsletter provider....
Navigate to the Customers section, then select the New Customers tab.
Click on the Date Created column header to sort the list by the created date. Then simply copy the customers who are new since you last added users to Mailchimp.
If you would like more control over exactly what gets imported or need to format things BEFORE you import, you can also export your New Customer list.
In your email newsletter provider, choose the list to add the new customers to. Click Add Subscribers, then Copy/Paste from Excel.
There is a 'Date Added' field you can use to sort the list by the newest customers, and then edit the list as you need in Excel.