Marked muted emails as read with Google AppsScript

markMutedAsRead.gs

// Create a new AppScript project (https://script.google.com/home/start)
// and schedule this to be run every hour
function markMutedAsRead() {
  var threads = GmailApp.search('is:muted is:unread');
  for (var i = 0; i < threads.length; i++) {
    threads[i].markRead();
  }
}