尝试用Java实现通过SMTP发送邮件，却出现“AUTH LOGIN failed”错误

Question

在过去的几天里，我一直在用头撞桌子，试图找出为什么在尝试实现 Java 代码以通过公司的 Outlook 服务器发送电子邮件时不断出现以下错误：

DEBUG SMTP: Attempt to authenticate using mechanisms: LOGIN PLAIN DIGEST-MD5 NTLM XOAUTH2 
DEBUG SMTP: Using mechanism LOGIN
DEBUG SMTP: AUTH LOGIN command trace suppressed
DEBUG SMTP: AUTH LOGIN failed
Exception in thread "main" javax.mail.AuthenticationFailedException: 535 5.7.0 authentication failed
    at com.sun.mail.smtp.SMTPTransport$Authenticator.authenticate(SMTPTransport.java:932)
    at com.sun.mail.smtp.SMTPTransport.authenticate(SMTPTransport.java:843)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:748)
    at javax.mail.Service.connect(Service.java:388)
    at javax.mail.Service.connect(Service.java:246)
    at javax.mail.Service.connect(Service.java:195)
    at javax.mail.Transport.send0(Transport.java:254)
    at javax.mail.Transport.send(Transport.java:124)

这是有问题的代码：

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;

public class SendEmail3 {

    public static void main(String[] args) throws Exception {

        Login e = new Login();

        String host = "mail.authsmtp.com";
        String port = "465";
        final String userName = e.getEmailUser();
        final String password = e.getEmailPassword();
        String toAddress = "first.last@email";
        String subject = "TEST";
        String message = "This is a test email";

        // sets SMTP server properties
        Properties properties = new Properties();
        properties.put("mail.smtp.host", host);
        properties.put("mail.smtp.port", port);
        properties.put("mail.smtp.auth", "true");
        properties.put("mail.debug", "true");
        // properties.put("mail.smtp.starttls.enable", "true");
        properties.put("mail.smtp.ssl.enable", "true");
        properties.put("mail.user", userName);
        properties.put("mail.password", password);

        // creates a new session with an authenticator
        Authenticator auth = new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(userName, password);
            }
        };
        Session session = Session.getInstance(properties, auth);

        // creates a new e-mail message
        Message msg = new MimeMessage(session);

        msg.setFrom(new InternetAddress(userName));
        InternetAddress[] toAddresses = { new InternetAddress(toAddress) };
        msg.setRecipients(Message.RecipientType.TO, toAddresses);
        msg.setSubject(subject);
        msg.setSentDate(new Date());

        // creates message part
        MimeBodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setContent(message, "text/html");

        // creates multi-part
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(messageBodyPart);

        // sets the multi-part as e-mail's content
        msg.setContent(multipart);

        // sends the e-mail
        Transport.send(msg);

    }

}

该错误在Transport.send(msg)处触发。任何指导将不胜感激。

Answer 1

您需要访问https://myaccount.google.com，确保安全并更改不太安全的 app.gmail.smtp 的访问权限，需要最新版本的授权，这就是它不起作用的原因。