// 关于QQ邮箱，还要设置SSL加密，加上以下代码即可MailSSLSocketFactory sf = new MailSSLSocketFactory();sf.setTrustAllHosts(true);props.put("mail.smtp.ssl.enable", "true");props.put("mail.smtp.ssl.socketFactory", sf);

参考消息：

import java.security.GeneralSecurityException;import java.util.Properties;import javax.mail.Authenticator;import javax.mail.Message;import javax.mail.MessagingException;import javax.mail.PasswordAuthentication;import javax.mail.Session;import javax.mail.Transport;import javax.mail.internet.InternetAddress;import javax.mail.internet.MimeMessage;import com.sun.mail.util.MailSSLSocketFactory;public class SendEmail {    public static void main(String [] args) throws GeneralSecurityException     {        // 收件人电子邮箱        String to = "XXXXX@qq.com";        // 发件人电子邮箱        String from = "XXXXXX@qq.com";        // 指定发送邮件的主机为 smtp.qq.com        String host = "smtp.qq.com";  //QQ 邮件服务器        // 获取系统属性        Properties properties = System.getProperties();        // 设置邮件服务器        properties.setProperty("mail.smtp.host", host);        properties.put("mail.smtp.auth", "true");        MailSSLSocketFactory sf = new MailSSLSocketFactory();        sf.setTrustAllHosts(true);        properties.put("mail.smtp.ssl.enable", "true");        properties.put("mail.smtp.ssl.socketFactory", sf);        // 获取默认session对象        Session session = Session.getDefaultInstance(properties,new Authenticator(){            public PasswordAuthentication getPasswordAuthentication()            {                return new PasswordAuthentication("429240967@qq.com", "授权的 QQ 邮箱密码"); //发件人邮件用户名、密码            }        });        try{            // 创建默认的 MimeMessage 对象            MimeMessage message = new MimeMessage(session);            // Set From: 头部头字段            message.setFrom(new InternetAddress(from));            // Set To: 头部头字段            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));            // Set Subject: 头部头字段            message.setSubject("This is the Subject Line!");            // 设置消息体            message.setText("This is actual message");            // 发送消息            Transport.send(message);            System.out.println("Sent message successfully....from runoob.com");        }catch (MessagingException mex) {            mex.printStackTrace();        }    }}