<dependency><groupId>com.sun.mail</groupId><artifactId>javax.mail</artifactId><version>1.6.2</version>
</dependency>

host=smtp.163.com
from=xxxxxxxxxx@163.com
to=xxxxxxxxxxx@qq.com
affix=src/main/java/a.png
affixName=a.png
user=xxxxxxxxxx
pwd=xxxxxxxxxxx      #授权码
subject=\u6D4B\u8BD5\u53D1\u9001\u90AE\u4EF6

package com.lfy.cn.JExcelApiTest;import java.io.IOException;
import java.util.Properties;import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;public class SendMailUtil {static String HOST = ""; // smtp服务器static String FROM = ""; // 发件人地址static String TO = ""; // 收件人地址static String AFFIX = ""; // 附件地址static String AFFIXNAME = ""; // 附件名称static String USER = ""; // 用户名static String PWD = ""; // 163的授权码static String SUBJECT = ""; // 邮件标题static String[] TOS = null;static {try {Properties props = new Properties(); props.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("config.properties"));//从自定义配置文件获取相关参数HOST=props.getProperty("host");FROM=props.getProperty("from");TO=props.getProperty("to");TOS=TO.split(",");AFFIX=props.getProperty("affix");AFFIXNAME=props.getProperty("affixName");USER=props.getProperty("user");PWD=props.getProperty("pwd");SUBJECT=props.getProperty("subject");} catch (IOException e) {e.printStackTrace();}}/*** 发送邮件* @param host* @param user* @param pwd*/public static void send(String context) {Properties props = new Properties();props.put("mail.smtp.host", HOST);//设置发送邮件的邮件服务器的属性（这里使用网易的smtp服务器）props.put("mail.smtp.auth", "true");  //需要经过授权，也就是有户名和密码的校验，这样才能通过验证（一定要有这一条）Session session = Session.getDefaultInstance(props);//用props对象构建一个sessionsession.setDebug(true);MimeMessage message = new MimeMessage(session);//用session为参数定义消息对象try {message.setFrom(new InternetAddress(FROM));// 加载发件人地址InternetAddress[] sendTo = new InternetAddress[TOS.length]; // 加载收件人地址for (int i = 0; i < TOS.length; i++) {  sendTo[i] = new InternetAddress(TOS[i]);  }message.addRecipients(Message.RecipientType.TO,sendTo);message.addRecipients(MimeMessage.RecipientType.CC, InternetAddress.parse(FROM));//设置在发送给收信人之前给自己（发送方）抄送一份，不然会被当成垃圾邮件，报554错message.setSubject(SUBJECT);//加载标题Multipart multipart = new MimeMultipart();//向multipart对象中添加邮件的各个部分内容，包括文本内容和附件BodyPart contentPart = new MimeBodyPart();//设置邮件的文本内容
            contentPart.setText(context);multipart.addBodyPart(contentPart);if(!AFFIX.isEmpty()){//添加附件BodyPart messageBodyPart = new MimeBodyPart();DataSource source = new FileDataSource(AFFIX);messageBodyPart.setDataHandler(new DataHandler(source));//添加附件的内容sun.misc.BASE64Encoder enc = new sun.misc.BASE64Encoder();//添加附件的标题messageBodyPart.setFileName("=?GBK?B?"+ enc.encode(AFFIXNAME.getBytes()) + "?=");multipart.addBodyPart(messageBodyPart);}message.setContent(multipart);//将multipart对象放到message中message.saveChanges(); //保存邮件Transport transport = session.getTransport("smtp");//发送邮件transport.connect(HOST, USER, PWD);//连接服务器的邮箱transport.sendMessage(message, message.getAllRecipients());//把邮件发送出去transport.close();//关闭连接} catch (Exception e) {e.printStackTrace();}}public static void main(String[] args) {send("内容");}
}