JAVA message.getAllRecipients（）。length返回不正确的值

Question

我正在使用javax.mail，IMAP提供商，并希望获得多个收件人。 我的电子邮件有3个收件人，但

System.out.println("AllRecipients: " + message.getAllRecipients().length);

和

System.out.println("Recipients: " + message.getRecipients(Message.RecipientType.TO).length);

返回值= 1。

代码：

public void checkEmail() throws MessagingException
{

    String host = "imap.example.host";
    Integer port = 993;
    String username = "exampleLogin";
    String password = "examplePassword";
    String provider = "imaps";
    String folderMail = "inbox";

    Properties properties = new Properties();

    properties.put("mail.imap.host", host);
    properties.put("mail.imap.socketFactory.port", port);
    properties.put("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
    properties.put("mail.imap.auth", "true");
    properties.put("mail.imap.port", port);

    Session session = Session.getDefaultInstance(properties, new javax.mail.Authenticator(){protected PasswordAuthentication getPasswordAuthentication(){
                return new PasswordAuthentication("username","password");
                }
            });

    Store store = session.getStore(provider);

    store.connect(host, port, username, password);

    try
    {

        Folder folder = store.getFolder(folderMail);

        folder.open(Folder.READ_WRITE);

        Message[] messages = folder.getMessages();

        System.out.println("messages in folder: " + messages.length);

        for (int messageNumber = 0, messageCount = messages.length; messageNumber < messageCount; messageNumber ++)
        {

            Message message = messages[messageNumber];
            System.out.println("---------------------------------");
            System.out.println("Email #: " + messageNumber);
            System.out.println("Subject: " + message.getSubject());
            System.out.println("AllRecipients: " + message.getAllRecipients().length);

        }

        folder.close(false);

    }
    catch (FolderNotFoundException e)
    {

        System.out.println(System.currentTimeMillis() + " :: Folder " + folderMail + " not found or empty");

    }

    System.out.println("FINISH");

}

任何人都可以帮忙吗？