OpenBadgesSender.js

var BASE_URL = 'https://sites.google.com/a/hawksey.info/sandbox/mozilla-open-badges-issuer-example'; // Google Sites page
// for script to handle issuing badges see https://script.google.com/d/1wOxT8VA2mhPVR4b4v7jMTOiIa3hNkUJyAcHUzUh6sObSITyOu3wKi4NS/edit?usp=sharing
/**
 * Handle form submit
 */
function onSubmit(e) {
  var doc = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = doc.getSheetByName("IssuedBadges"); // note: assumed sheet name
  var email = e.namedValues['Email'][0]; // note: assumed question name with person's email address
  var uid = getUID();
  // write data to IssuedBadges sheet (you can include more info)
  sheet.getRange(sheet.getLastRow()+1, 1, 1, 3).setValues([[uid, email, e.namedValues['Timestamp'][0]]]);
  // send email
  sendEmail(email, uid);
}

/**
 * Sends an email 
 * @param {String} email address of person receiving badge.
 * @param {String} uuid used to identify issued badge.
 */
function sendEmail(email, uuid) {
  var claimString = '?key='+SpreadsheetApp.getActiveSpreadsheet().getId()+'&uid='+uuid;
  var url = BASE_URL + claimString;
  var text = 'Thank you for taking time to try this App Script Open Badges Issuer. To claim your badge in Google Sites visit ' + url;
  var textHtml = HtmlService.createTemplateFromFile('mailText');
  textHtml.url = url; // passing variables into templates https://developers.google.com/apps-script/guides/html/templates#pushing_variables_to_templates
  MailApp.sendEmail(email, 
                    "Thank you for trying the App Script Open Badges Issuer", 
                    text, 
                    {replyTo:"no-reply@hawksey.info", htmlBody: textHtml.evaluate().getContent()});
}

/**
 * Gets RFC4122 version 4 compliant UUID. Based on http://stackoverflow.com/a/8809472/1027723
 * @return {String} uuid.
 */
function getUID() {
  var d = new Date().getTime();
  var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = (d + Math.random()*16)%16 | 0;
    d = Math.floor(d/16);
    return (c=='x' ? r : (r&0x3|0x8)).toString(16);
  });
  return uuid;
}