确认邮箱账号和密码是否正确。
确认邮箱服务商是否开启了IMAP/POP3服务。
检查代码中是否正确配置了SMTP/IMAP/POP3的相关参数。
参考代码:
使用JavaMail发送邮件:
String host = "smtp.gmail.com";
String port = "587";
String username = "your-email-address@gmail.com";
String password = "your-email-password";
Properties properties = new Properties();
properties.put("mail.smtp.starttls.enable", "true");
properties.put("mail.smtp.host", host);
properties.put("mail.smtp.port", port);
properties.put("mail.smtp.auth", "true");
Session session = Session.getInstance(properties,
        new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
        });
try {
    Message message = new MimeMessage(session);
    message.setFrom(new InternetAddress("your-email-address@gmail.com"));
    message.setRecipients(
            Message.RecipientType.TO,
            InternetAddress.parse("recipient-email-address@example.com")
    );
    message.setSubject("Testing JavaMail API");
    message.setText("Dear Recipient," +
            "\n\nThis is a test email sent using JavaMail API. " +
            "Please do not reply to this email." +
            "\n\nThank you." +
            "\n\nBest regards," +
            "\nYour Name");
    Transport.send(message);
    System.out.println("Email sent successfully.");
} catch (MessagingException e) {
    e.printStackTrace();
}
使用JavaMail接收邮件:
String host = "imap.gmail.com";
String port = "993";
String username = "your-email-address@gmail.com";
String password = "your-email-password";
Properties properties = new Properties();
properties.put("mail.imap.host", host);
properties.put("mail.imap.port", port);
properties.put("mail.imap.starttls.enable", "true");
properties.put("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
Session session = Session.getInstance(properties,
        new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
        });
try {
    Store store =