添加依赖

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

接口定义

/**

* Description
* 
* @author <a href="https://qiankunpingtai.cn">qiankunpingtai</a>
* @Date: 2021/1/27 10:12
  */
public interface IMailService {
/**
  
  * 发送文本邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
    */
    public void sendSimpleMail(String to, String subject, String content);
  
  /**
  
  * 发送HTML邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
    */
    public void sendHtmlMail(String to, String subject, String content);
  
  /**
  
  * 发送带附件的邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
  * @param filePath 附件
    */
    public void sendAttachmentsMail(String to, String subject, String content, String filePath);
    }

接口实现

import com.chinamobile.service.IMailService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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;

/**

* Description
* 
* @author <a href="https://qiankunpingtai.cn">qiankunpingtai</a>
* @Date: 2021/1/27 10:14
  */
@Service
public class IMailServiceImpl implements IMailService {
private final Logger logger = LoggerFactory.getLogger(IMailServiceImpl.class);
/**
  
  * Spring Boot 提供了一个发送邮件的简单抽象，使用的是下面这个接口，这里直接注入即可使用
    */
    @Autowired
    private JavaMailSender mailSender;
  
  /**
  
  * 配置文件中我的qq邮箱
    */
    @Value("${spring.mail.from}")
    private String from;
  
  /**
  
  * 简单文本邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
    */
    @Override
    public void sendSimpleMail(String to, String subject, String content) {
    //创建SimpleMailMessage对象
    SimpleMailMessage message = new SimpleMailMessage();
    //邮件发送人
    message.setFrom(from);
    //邮件接收人
    message.setTo(to);
    //邮件主题
    message.setSubject(subject);
    //邮件内容
    message.setText(content);
    //发送邮件
    mailSender.send(message);
    }
  
  /**
  
  * html邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
    */
    @Override
    public void sendHtmlMail(String to, String subject, String content) {
    //获取MimeMessage对象
    MimeMessage message = mailSender.createMimeMessage();
    MimeMessageHelper messageHelper;
    try {
    messageHelper = new MimeMessageHelper(message, true);
    //邮件发送人
    messageHelper.setFrom(from);
    //邮件接收人
    messageHelper.setTo(subject);
    //邮件主题
    message.setSubject(subject);
    //邮件内容，html格式
    messageHelper.setText(content, true);
    //发送
    mailSender.send(message);
    //日志信息
    logger.info("邮件已经发送。");
    } catch (MessagingException e) {
    logger.error("发送邮件时发生异常！", e);
    }
    }
  
  /**
  
  * 带附件的邮件
  * @param to 收件人
  * @param subject 主题
  * @param content 内容
  * @param filePath 附件
    */
    @Override
    public void sendAttachmentsMail(String to, String subject, String content, String filePath) {
    MimeMessage message = mailSender.createMimeMessage();
    try {
    MimeMessageHelper helper = new MimeMessageHelper(message, true);
    helper.setFrom(from);
    helper.setTo(to);
    helper.setSubject(subject);
    helper.setText(content, true);
  
    ```
    FileSystemResource file = new FileSystemResource(new File(filePath));
     String fileName = filePath.substring(filePath.lastIndexOf(File.separator));
     helper.addAttachment(fileName, file);
     mailSender.send(message);
     //日志信息
     logger.info("邮件已经发送。");
    ```
  
    } catch (MessagingException e) {
    logger.error("发送邮件时发生异常！", e);
    }
  
  }

}

参数配置

163 邮箱

spring.mail.host=smtp.163.com
spring.mail.protocol=smtps
spring.mail.port=465
spring.mail.username=XXXX
spring.mail.password=XXXX
spring.mail.from=XXXX
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=false
spring.mail.properties.mail.smtps.ssl.checkserveridentity=false
spring.mail.properties.mail.mime.charset=UTF-8
spring.mail.defaultEncoding=UTF-8
spring.mail.properties.mail.smtps.ssl.trust=*

126 邮箱

chinamobile 邮箱

spring.mail.host=XXX
spring.mail.username=XXX
spring.mail.password=XXX
spring.mail.protocol=smtp
spring.mail.port=465

spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.ssl.enable=true
spring.mail.properties.mail.debug=true
spring.mail.properties.mail.smtp.timeout=1000