Anti Newsletter Script for Gmail (and Archive)

anti-newsletters.gs

function processInbox() {
  var label = GmailApp.getUserLabelByName("Newsletter");
  if(!label){
    label = GmailApp.createLabel("Newsletter");
  }
   // process all recent threads in the Inbox
   var threads = GmailApp.search("newer_than:2d  -minusimportantthings");
   for (var i = 0; i < threads.length; i++) {
      // get all messages in a given thread
      var messages = threads[i].getMessages();
      var thread = threads[i];
      for (var j = 0; j < messages.length; j++) {
         var message = messages[j];
         var body = message.getRawContent();
         // any email with unsubscribe in the email header OR message content
         if ((body.indexOf("Unsubscribe") > -1) || body.indexOf("unsubscribe") > -1) {
          thread.addLabel(label)
          thread.moveToArchive();
          thread.markRead();
         }
      }
   }
}

Video guide: https://twitter.com/_RobertLowe/status/1462459320331911168