Autoarchive for GMail

gmail-auto-archive.js

function gmailAutoarchive() {
  var holdDays = 8; 
  var maxDate = new Date();
  maxDate.setDate(maxDate.getDate()-holdDays);
  
  var threads = GmailApp.getInboxThreads(0,500).filter(function(thread) {
    // Return only old threads and without stars
    return (thread.getLastMessageDate() < maxDate && thread.hasStarredMessages() == false);
  });
  
  var batch_size = 100;
  while (threads.length) {
    var this_batch_size = Math.min(threads.length, batch_size);
    var this_batch = threads.splice(0, this_batch_size);
    GmailApp.moveThreadsToArchive(this_batch);
  }
}