java发送邮件,遇到的奇葩问题

package com.dsp;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.*;
import javax.mail.internet.*;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Properties;

/**
 *@author wangyuxiang
 *@Description
 *@Date 2018/2/2 上午11:37
 **/
public class SendMail {

    public static void main(String[] args) {

        try {
            String path = System.getProperty("user.dir") + "/mail.properties";
            System.out.println(path+"");
            Properties properties = System.getProperties();
            InputStream in = new BufferedInputStream(new FileInputStream(path));

            properties.load(in);

            final String Sender = new String(properties.getProperty("Sender").getBytes("ISO8859-1"), "UTF-8");
            String host = properties.getProperty("host");
            String Recipients = new String(properties.getProperty("Recipients").getBytes("ISO8859-1"), "UTF-8");
            final String SenderPassword = new String(properties.getProperty("SenderPassword").getBytes("ISO8859-1"), "UTF-8");
            String title = new String(properties.getProperty("title").getBytes("ISO8859-1"), "UTF-8");
            String text = new String(properties.getProperty("text").getBytes("ISO8859-1"), "UTF-8");
            String fileDir = new String(properties.getProperty("fileDir").getBytes("ISO8859-1"), "UTF-8");


            // 设置邮件服务器
            properties.setProperty("mail.smtp.host", host);
            properties.put("mail.smtp.auth", "true");

            Authenticator authenticator = new Authenticator() {
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(Sender, SenderPassword);
                }
            };

            // 获取默认的 Session 对象。
            Session session = Session.getDefaultInstance(properties, authenticator);

            MimeMessage message = new MimeMessage(session);
            System.out.println(title + text);
            message.setFrom(new InternetAddress(Sender));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(Recipients));
            message.setSubject(title, "UTF-8");

            Multipart multipart = new MimeMultipart();

            /*设置文本消息部分*/
            BodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setContent(text, "text/html;charset=UTF-8");
            messageBodyPart.setText(text);
            multipart.addBodyPart(messageBodyPart);

            /*附件部分*/
            File file = new File(fileDir);
            File[] fileList = file.listFiles();
            for (File fl:fileList){
                if (fl.isFile()){
                    // 附件
                    messageBodyPart = new MimeBodyPart();
                    DataSource source = new FileDataSource(fl);
                    messageBodyPart.setDataHandler(new DataHandler(source));
                    messageBodyPart.setFileName(MimeUtility.encodeWord(fl.getName()));
                    multipart.addBodyPart(messageBodyPart);
                }
            }

            // 发送完整消息
            message.setContent(multipart);
            // 发送消息
            Transport.send(message);
            System.out.println("Sent message successfully....");
        } catch (Exception mex) {
            mex.printStackTrace();
        }
    }
}

 1 #发件人电子邮箱&密码
 2 Sender=***@126.com
 3 SenderPassword=******
 4 #发送邮件的主机
 5 host=smtp.126.com
 6 
 7 #收件人电子邮箱
 8 Recipients=***@qq.com
 9 
10 title=邮件标题
11 text=邮件内容
12 fileDir=发送附件的绝对目录 (会将目录下的所有文件,除文件夹添加为附件发送)