Java Mail Api 不返回所有邮件

Question

您好，我正在尝试获取 Gmail 收件箱的所有邮件，但它没有返回所有邮件。它返回一些太旧的邮件。不是最新的。我正在使用以下代码进行测试:

public class ReadEmail {

    public static void check(String host, String storeType, final String user, final String password) {
        try {

            // create properties field
            Properties properties = new Properties();

            properties.put("mail.pop3.host", host);
            properties.put("mail.pop3.port", "995");
            properties.put("mail.pop3.starttls.enable", "true");
            Session emailSession = Session.getDefaultInstance(properties);
            emailSession.setDebug(true);

            // create the POP3 store object and connect with the pop server
            Store store = emailSession.getStore("pop3s");

            store.connect(host, user, password);

            // create the folder object and open it
            Folder emailFolder = store.getFolder("Inbox");
            emailFolder.open(Folder.READ_ONLY);

            // retrieve the messages from the folder in an array and print it
            Message[] messages = emailFolder.getMessages();
            System.out.println("messages.length---" + messages.length);

            // close the store and folder objects
            emailFolder.close(false);
            store.close();

        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        } catch (MessagingException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {

        String host = "pop.gmail.com";
        String mailStoreType = "pop3";
        String username = "****@gmail.com";// change accordingly
        String password = "****";// change accordingly

        check(host, mailStoreType, username, password);

    }
}

1. 我没有发现我的代码有什么问题。我已经完成了给定的其他设置here 。

2. 我也只想获取主要选项卡邮件。如何在我的代码中应用选项卡级过滤器？

Answer 1

取自 here

Q: Why don't I see all my messages when accessing Gmail with POP3?

A: Gmail has settings that control which of your messages are availablevia the POP3 protocol. See the Gmail settings page to change theconfiguration of your Gmail account.

关于 POP3:

POP3 is a very limited protocol for accessing a single mailbox. It is much less capable than IMAP