Google Apps Script to forward email on header match

google-apps-script-forward-email-on-header-match.gs

// 1. Add a Gmail "azure" filter to all Azure email for instance
// Matches: from:([email protected])
// Do this: Skip Inbox, Apply label "azure"

// 2. Add a Gmail "azure-forwarded" filter to keep track of those threads that have forwarded messages.

// 3. Add this script to a new project at https://script.google.com

// 4. Replace "X-VSS-Scope: example" with your "X-VSS-Scope" header (open an email, then click "Show original")
//    Replace "[email protected]" with your preferred forwarding email target.

// 4. Run it once. It will ask you for access to your Gmail.

// 5. Add a time trigger to run this function every minute, and notify you hourly of errors.

function main() {
  var azureForwardedLabel = GmailApp.getUserLabelByName('azure-forwarded');
  var threads = GmailApp.search('in:azure is:unread');
  threads.forEach(function(thread) {
    var messages = thread.getMessages();
    var matched = false;
    messages.forEach(function(message) {
      var body = message.getRawContent();
      if (!body.match(/X-VSS-Scope: example/g)) {
        return;
      }
      matched = true;
      message.forward('[email protected]');
      message.markRead();
      Logger.log({forwarded: message});
    });
    thread.addLabel(azureForwardedLabel);
  });
}