Thanks for your reply!
We set Opt-In to Single Opt-in under tab General here: /wp-admin/admin.php?page=newsletter_subscription_options
We set Ask users to subscribe to “No” and Enable WooCommerce Extension to “Yes”. We set Send users an email to confirm subscription to “No”. We checked two preference lists where woocommerce customers are supposed to be added on checkout by default.
(/wp-admin/admin.php?page=newsletter_woocommerce_index)
However our test user receives a confirmation email from newsletter plugin after successfull checkout – even though we set confirmation email to No in Woocommerce extension of your plugin.
Any ideas?