function main() {
  // Settings
  var campaignName = "Campaign Name";
  var metricsToTrack = ["Clicks", "Conversions", "Cost"]; 
  var changeThreshold = 0.2; // 20% increase or decrease
  var comparisonPeriod = "LAST_7_DAYS"; // Timeframe for comparison
  var recipientEmail = "your_email@example.com";

  // Get the campaign
  var campaign = AdsApp.campaigns().withCondition("Name = '" + campaignName + "'").get().next();

  // Fetch performance data for the current and previous periods
  var currentStats = campaign.getStatsFor("TODAY");
  var previousStats = campaign.getStatsFor("PREVIOUS_" + comparisonPeriod); 

  // Analyze each metric
  for (var i = 0; i < metricsToTrack.length; i++) {
    var metric = metricsToTrack[i];
    var currentValue = currentStats.get(metric);
    var previousValue = previousStats.get(metric);

    var changePercentage = (currentValue - previousValue) / previousValue;

    // Send alert if the change is significant
    if (Math.abs(changePercentage) >= changeThreshold) {
      var direction = changePercentage > 0 ? "increased" : "decreased";
      var subject = "Performance Alert: " + campaignName;
      var body = metric + " has " + direction + " by " + (changePercentage * 100).toFixed(0) + "% compared to the previous " + comparisonPeriod.toLowerCase() + ".";
      MailApp.sendEmail(recipientEmail, subject, body);
    }
  }
}