SpringBoot 2.x 集成QQ邮箱、网易系邮箱、Gmail邮箱发送邮件

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

spring:
  mail:
    host: smtp.qq.com #发送邮件服务器
    username: xx@qq.com #QQ邮箱
    password: xxxxxxxxxxx #客户端授权码
    protocol: smtp #发送邮件协议
    properties.mail.smtp.auth: true
    properties.mail.smtp.port: 465 #端口号465或587
    properties.mail.smtp.starttls.enable: true
    properties.mail.smtp.starttls.required: true
    properties.mail.smtp.ssl.enable: true
    default-encoding: utf-8
    from: xx@qq.com #与上面的username保持一致

spring:
  mail:
    host: smtp.126.com
    username: xx@126.com
    password: xxxxxxxx
    protocol: smtp
    properties.mail.smtp.auth: true
    properties.mail.smtp.port: 994 #465或者994
    properties.mail.smtp.starttls.enable: true
    properties.mail.smtp.starttls.required: true
    properties.mail.smtp.ssl.enable: true
    default-encoding: utf-8
    from: xx@126.com

spring:
  mail:
    host: smtp.gmail.com
    username:xxx@gmail.com
    password: xxxxx #Gmail账号密码
    protocol: smtp
    properties.mail.smtp.auth: true
    properties.mail.smtp.port: 465
    properties.mail.smtp.starttls.enable: true
    properties.mail.smtp.starttls.required: true
    properties.mail.smtp.ssl.enable: true
    from: xxx@gmail.com
    default-encoding: utf-8

package cn.qiucode.service;
import javax.mail.MessagingException;
 * Created by wuming on 2019/6/1.
public interface MailService  {
     * 发送文本邮件
     * @param to
     * @param subject
     * @param content
    public void sendSimpleMail(String to, String subject, String content);
     * 发送HTML邮件
     * @param to
     * @param subject
     * @param content
     * @throws MessagingException
    public void sendHtmlMail(String to, String subject, String content) throws MessagingException;
}

package cn.qiucode.service.impl;
import cn.qiucode.service.MailService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;
import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;
 * Created by wuming on 2019/6/1.
@Service("mailService")
public class MailServiceImpl implements MailService {
    @Autowired
    private JavaMailSender mailSender;
    @Value("${spring.mail.from}")
    private String from;
     * 发送文本邮件
     * @param to
     * @param subject
     * @param content
    @Override
    public void sendSimpleMail(String to, String subject, String content) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(subject);
        message.setText(content);
        mailSender.send(message);
     * 发送HTML邮件
     * @param to
     * @param subject
     * @param content
    @Override
    public void sendHtmlMail(String to, String subject, String content) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(content, true);
        mailSender.send(message);
}

@Autowired
    private MailService mailService;
    //在添加评论/留言的方法里调用service
    //发送邮箱通知
        asyncSendMail(messageParam.getArticleId(),messageParam.getContent());
//异步处理线程
    public void asyncSendMail(final Integer articleId,final String content){
        ThreadUtil.execute(new Runnable() {
            @Override
            public void run() {
                    String subject=null==articleId ? "有新游客留言了！" : "有游客评论了ID为【"+articleId+"】这篇文章";
                    String msgTitle=null==articleId ? "留言内容如下:" : "评论内容如下:";
                    mailService.sendHtmlMail("2834491983@qq.com",subject,"<body style=\"text-align: center;margin-left: auto;margin-right: auto;\">\n"
                            + "    <div id=\"welcome\" style=\"text-align: center;position: absolute;\" >\n"
                            +"        <h3>"+msgTitle+"</h3>\n"
                            +"        <span>"+content+"</span>"
                            + "    </div>\n" + "</body>");