Google Apps脚本中的错误：使用getPlainText时出现mime类型错误

Question

当我尝试使用GmailMessage类的getPlainBody（）方法时。当我执行以下代码时，会显示错误消息“无效的MIME类型”。任何人都可以帮我验证代码中的错误吗？

function processLabel(labelName) {
  var targetLabel = GmailApp.getUserLabelByName(labelName);
  var targetThreads = targetLabel.getThreads();
  return targetThreads;
};

function getEmailPlainText() {
  var targetThreads = processLabel('@today');
  var threadsCount = targetThreads.length;
  for (var i = 0; i < threadsCount; i++) {
    var targetThread = targetThreads[i];
    var messageCount = targetThread.getMessageCount();
    var subject = targetThread.getFirstMessageSubject();
    var lastMessage = targetThread.getMessages()[messageCount-1];
    var lastMessageContent = lastMessageContent = lastMessage.getPlainBody();
};    

Answer 1

当邮件包含某种类型的附件时，这似乎是一个错误。

Check here and vote it up