Find out how to do it here:
Activate the module
You can activate the “Register for newsletter emails” under Settings > Module.
View for your end customer
After your customer has placed an order and completed the purchase, they can register directly for your newsletter with one click.
Export customer data
Under Statistics > Export you now have the option of exporting the “Newsletter opt-in” so that you can see which of your customers have registered for the newsletter. Then you simply have to import the email addresses into the newsletter programme of your choice, eg. Mailchimp und CleverReach.