<!-- 導入javamail的坐標 -->
<dependency>
    <groupId>javax.mail</groupId>
    <artifactId>mail</artifactId>
    <version>1.4.7</version>
</dependency>

import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMessage.RecipientType;
import java.util.Properties;
public class MailUtil {
   public static String smtp_host = "smtp.163.com"; // 網易
   public static String username = "222@163.com"; // 郵箱
   public static String password = "q7w8e9a4s5d6"; // 授權碼（登錄郵箱-->設置-->郵箱安全設置-->客戶端授權密碼），這里不是郵箱的密碼，切記！
   public static String from = "222@163.com"; // 來源郵箱，使用當前賬號

   public static void sendMail(String to, String subject, String text) throws Exception {
      // 1 準備發(fā)送郵件需要的參數(shù)
      Properties props = new Properties();
      // 設置主機地址 smtp.qq.com smtp.126.com smtp.163.com
      props.put("mail.smtp.host", smtp_host);
      // 是否打開驗證:只能設置true，必須打開
      props.put("mail.smtp.auth", true);

      // 2 連接郵件服務器
      Session session = Session.getDefaultInstance(props);
      // 3 創(chuàng)建郵件信息
      MimeMessage message = new MimeMessage(session);

      // 4 設置發(fā)送者
      InternetAddress fromAddress = new InternetAddress(from);
      message.setFrom(fromAddress);
      // 5 設置接收者
      InternetAddress toAddress = new InternetAddress(to);
      // to:直接接收者 cc：抄送 bcc暗送
      message.setRecipient(RecipientType.TO, toAddress);
      // 6 設置主題
      message.setSubject(subject);
      // 7 設置正文
      message.setText(text);

      // 設置HTML方式發(fā)送
      //message.setContent(text, "text/html;charset=utf-8");

      // 8 發(fā)送:坐火箭
      Transport transport = session.getTransport("smtp");// 參數(shù)不能少，表示的是發(fā)送協(xié)議
      // 登錄郵箱,此處的密碼是授權碼
      transport.connect(username, password);
      transport.sendMessage(message, message.getAllRecipients());
      transport.close();

      System.out.println("ok");
   }
   
   public static void main(String[] args) {
      try {
         MailUtil.sendMail("333@qq.com", "激活測試", "test");
      } catch (Exception e) {
         e.printStackTrace();
      }
   }
   
}

public static void main(String[] args) {
    try {
        MailUtil.sendMail("333@qq.com", "激活測試", "test");
    } catch (Exception e) {
        e.printStackTrace();
    }
}