Good luck unsubscribing from email newsletters sent by Best Buy and Hertz. As the below video elaborates, when your email address (that receives the newsletters) is not recognized as a valid address, a failure occurs.
Let this be a lesson to email marketing companies. If you provide a means for a recipient to unsubscribe, don’t make the process difficult and ensure the address is in your database for prompt removal.
Shameless plug: To receive best practices on new and emerging media and how nonprofit and public sector organizations are communicating effectively, please sign up for my newsletter here.