In this problem, Unroll.me can help you. It unsubscribe all mailing lists in a few minutes. This is a new service and still it is in beta. It works only for subscriptions delivered to Gmail or Yahoo accounts. But company is working to add more email service support.
To unsubscribe all mailing list, go to the unroll.me and select the email service you use. In my case, it is Gmail. So i will simply select from drop down and press go. After this step, it will ask for permission to access your Gmail account. Allow it to access your Gmail by clicking on allow button.
It will scan your inbox and show you a list of all email newsletters you have subscribed. You will also see two icons in front of each service. Minus icon is to unsubscribe and reload icon is to go back to the inbox. Just click on minus sign in front of the service to unsubcribe individually.
Service is in beta so there may be some possibilities of security risks. But no issue have been identified yet. I am also using this service without any problem. This service will save your inbox from unwanted emails filling your inbox. A must use online utility.
