404 Check

//The URL you are checking for published status
var url = URL;

//The email you want to notify
var email = EMAIL;

function checkForPublish() {
  var scriptProperties = PropertiesService.getScriptProperties();

  if (scriptProperties.getProperty('PUBLISHED') == 'true') {
    Logger.log('ALREADY PUBLISHED');
    return;
  }

  var result=UrlFetchApp.fetch(url,{muteHttpExceptions: true});
  if (result.getResponseCode() == 200) {
    Logger.log('PUBLISHED');
    scriptProperties.setProperty('PUBLISHED', 'true');
    MailApp.sendEmail(email, "It's alive!", "The URL " + url + " has been published!");
  } else {
    Logger.log('NOT PUBLISHED');
  }
}