Two-way sync for Magneto newsletter subscribers and one-way sync for Magnento customers.

• Automatic synchronization between your Magento email subscriber list and one of your Mailigen email lists. When users subscribe to the newsletter in Magento, they will be added to the selected Mailigen contact list.
• Two-way synchronization when it comes to subscriber status change. When users unsubscribe from your Magento list, they will be removed also from your Mailigen list. And vice versa, users will be removed from your Magento list when unsubscribed from your Mailigen list.
• Automatic synchronization between your Magento customer list and one of your Mailigen email lists. When a customer registers in Magento, they will be added to the selected Mailigen contact list.
• One-way Magento customers synchronization. All customer information (customer address, last login date, items in the cart, orders information) from Magento store will be synced with selected Mailigen contact list.

https://www.mailigen.com/assets/templates/rise-n-tell/pdf/MailigenSynchronizer-MagentoModul-UserGuide-v1.pdf

https://www.mailigen.com/about/contact-us