Consumers frustrated by email marketing sites that make it difficult to unsubscribe could take direct action by getting the unscrupulous marketing men blocked by email providers and ISPs, according to email delivery experts.
Technically it is illegal to run an opt-in marketing campaign that doesn't have an unsubscribe function, but consumers still often find it difficult to opt-out when they tire of emails from a charity or company newsletter they have signed up for.
According to delivery company Return Path, customers locked into a company's emails will react by reporting the company as spam, even if they have intentionally signed up for the messages, which could lead to all the company's messages being blocked.
Read more: http://www.pcpro.co.uk/news/enterprise/362629/direct-action-turns-email-newsletters-into-spam
I usually just have Outlook delete permanently for that kind of junk.