Impacted versions:
Odoo 10
Steps to reproduce:
Click in a Massmail on "Unsubscribe"
Current behavior:
Redirect to a 404 error page called "/ unsubscribe_from_list"
Expected behavior:
User should be removed from the Massmail Recipient list and redirected to a page that confirms the logout
if you feel this as an issue : please post it in the github