Extension include a List-Unsubscribe header in your newsletter emails.

It will reduce complaints because your recipients will be able to easily and reliably unsubscribe if they want to. Frustrated users are likely to hit the "Report Spam" button or complain in some other way about the email that they requested, hurting your sender reputation.

1. Go to Magento2 root folder

2. Enter following commands to install module:

   composer require faonni/module-newsletter

   Wait while dependencies are updated.

3. Enter following commands to enable module:

   php bin/magento setup:upgrade
   php bin/magento setup:di:compile
   php bin/magento setup:static-content:deploy  (optional)