Google Apps Script to send emails when an new Google Site Announcement is made (In response to https://plus.google.com/109310290306060614500/posts/JYMPQ2mLuEt )

gistfile1.js

/*
1. Set two variables below
2. Run > setup (twice, once to authenticate the script, second to actually run
3. Rescources > Current project trigger's and then click 'No triggers set up. Click here to add one now.'
You can accept the defaults to run emailAnnouncements() every hour
*/


var url_of_announcements_page = "https://sites.google.com/site/appsscripttemplates/home/announcetest"; // where your site page is
var who_to_email = "youremail@example.com" // who to send to (it can be a comma seperated list) 

function emailAnnouncements(){
  var page = SitesApp.getPageByUrl(url_of_announcements_page); // returns a page object
  if(page.getPageType() == SitesApp.PageType.ANNOUNCEMENTS_PAGE){ // test if page object is announcement page
    // get the last 10 announcements 
    var announcements = page.getAnnouncements({ start: 0,
                                               max: 10,
                                               includeDrafts: false,
                                               includeDeleted: false});
    announcements.reverse(); // reverse the result order so oldest first                                          
    for(var i in announcements) { // loop the individual announcements
      var ann = announcements[i]; // just creating a little shortcut
      var updated = ann.getLastUpdated().getTime(); // get when updated
      if (updated > ScriptProperties.getProperty('last-update')){ // if greater than last update send email
        var options = {}; // options used in MailApp
        // create html body of the email using an announcement
        options.htmlBody = Utilities.formatString("<h1><a href='%s'>%s</a></h1>%s", ann.getUrl(), ann.getTitle(), ann.getHtmlContent());
        // send the email
        MailApp.sendEmail(who_to_email, "Announcement "+ann.getTitle(), ann.getTextContent()+"\n\n"+ann.getUrl(), options);
        // update the last email sent
        ScriptProperties.setProperty('last-update',updated);
      }
    }
  }
}

function setup(){
  ScriptProperties.setProperty('last-update',new Date().getTime());
}