Java发送邮件

参考了“菜鸟教程”和stack overflow

准备工作

将mail.jar和activation.jar加入classpath.

说明

发送方为163邮箱，需要设置host等参数。

接收方可以是其他种类邮箱，比如qq邮箱等。

简单邮件发送

注意创建session时需要传入授权参数，否则会抛出异常 javax.mail.AuthenticationFailedException: failed to connect, no password specified?

public static void Send163Email() {
        String to = "to@163.com";
        String from = "from@163.com";
        
        Properties properties = System.getProperties();

        properties.put("mail.host", "smtp.163.com");
        properties.put("mail.transport.protocol", "smtp");
        properties.put("mail.smtp.auth", true);
        
        Session session = Session.getDefaultInstance(properties, 
                new javax.mail.Authenticator(){
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(
                            "from@163.com", "授权码");// Specify the Username and the PassWord
                    }
            });
        session.setDebug(true);
        
        MimeMessage message = new MimeMessage(session);

        try {
            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            message.setSubject("This is the Subject Line!");
            message.setText("This is actual message.");
            Transport.send(message);
            System.out.println("Sent message sucessfully!");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        }
    }

带附件邮件发送

public static void Send163EmailWithAttachment() {
        String to = "to@163.com";
        String from = "from@163.com";
        
        Properties properties = System.getProperties();

        properties.put("mail.host", "smtp.163.com");
        properties.put("mail.transport.protocol", "smtp");
        properties.put("mail.smtp.auth", true);
        
        Session session = Session.getDefaultInstance(properties, 
                new javax.mail.Authenticator(){
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(
                            "from@163.com", "授权码");// Specify the Username and the PassWord
                    }
            });
        session.setDebug(true);
        
        MimeMessage message = new MimeMessage(session);

        try {
            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            message.setSubject("This is the Subject Line(Text and file)!");

            BodyPart messageBodyPart=new MimeBodyPart();
            messageBodyPart.setText("This is a message body.
2017年11月28日");
            Multipart multipart=new MimeMultipart();
            multipart.addBodyPart(messageBodyPart);
            //attachment
            messageBodyPart=new MimeBodyPart();
            String filename="文件名（带路径）";
            DataSource source=new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            multipart.addBodyPart(messageBodyPart);
            
            message.setContent(multipart);
            Transport.send(message);
            System.out.println("Sent message sucessfully!");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        }
    }