The Gmail to Evernote program will automatically send your Gmail message to your Evernote account using Google Scripts. It reads the various parameters from a Google sheet (like the default tag name and Evernote notebook name) and forwards the matching email threads to Evernote using the GmailApp service.

var sheet = SpreadsheetApp.getActiveSpreadsheet();

var params = sheet.getRange('D3:D7').getValues();

// Gmail Label name to Monitor
var label = GmailApp.getLabelByName(params[1][0].trim().replace(/\\s+/g, '-'));

var threads = label.getThreads();

for (var t in threads) {
  var messages = threads[t].getMessages();

  // Forward the latest message in the thread to Evernote
  var message = messages[messages.length - 1];

  // Append the Evernote notebook and tag to the subject
  var subject = [message.getSubject(), params[2][0], params[3][0]].join(' ');

  try {
    message.forward(params[0][0], { subject: subject });
  } catch (f) {
    Logger.log(f.toString());
  }

  // Trash the message after forwarding to Evernote
  if (params[2][0].match(/y/i)) {
    threads[t].moveToTrash();
  } else {
    threads[t].removeLabel(label);
  }
}