Explanation
To automatically unsubscribe customers who respond to marketing emails asking to be removed from the mailing list, the admin should take two steps:
Ensure a Custom response is enabled for Automated Response in Reply Mail Management. This will allow Marketing Cloud to process replies that contain keywords such as unsubscribe, remove, or opt out and update the subscriber status accordingly.
Verify Reply Mail Management has been enabled in the account. This will allow Marketing Cloud to handle replies to marketing emails and route them to a designated email address or domain.