Unsubscribe from Bulk Emails in Gmail
Gmail Unsubscribe is an open source Google Script to help you easily unsubscribe your email address from unwanted newsletters and other bulk emails in Gmail. Follow this step-by-step guide for configuration.
Unroll.me, a free online web app, also lets you unsubscribe from junk emails in Gmail with one click. This Google Script is open source and, unlike Unroll.me, it neither collects any of your email messages nor does it sell your data to Uber.