电子邮件与Java发送邮件的历史
电子邮件原理
- 电子邮件服务器
- 电子邮箱
- 邮件客户端
- 邮件传输协议
- 邮件格式
- 电子邮件发送和接收流程
电子使用场景
SpringBoot实现发送电子邮件
- 准备账号
- 构建项目并配置
- 实现服务端代码
- 新建邮件模板
- 测试发送邮件
总结
相关链接

从1969年10月世界上的第一封电子邮件发出，到2019年，已经过去将近半个世纪了。虽然即时通讯和视频会议，甚至全息投影都变得日益普及，但电子邮件依然有着广泛的使用场景和不可撼动的历史地位。

SpringBoot拥有强大的生态链，几乎可以连接所有主流的开源库。

下面我们就从电子邮件发送的历史再到原理，然后如何自己配置邮件服务器并发送邮件，一步步讲解。

本文实现源码可以在这里找到： SpringBoot发送电子邮件源码

电子邮件与Java发送邮件的历史

1969年10月，世界上的第一封电子邮件

1969年10月世界上的第一封电子邮件是由计算机科学家Leonard K.教授发给他的同事的一条简短消息。第一条网上信息就是‘LO’，意思是‘你好！’。

1987年9月14日中国的第一封电子邮件

在此之后，1987年9月14日中国的第一封电子邮件，这封邮件是由德国维尔纳·措恩与中国的王运丰在北京计算机应用技术研究所，发往德国一个大学的，邮件内容颇具深意，“Across the Great Wall we can reach every corner in the world.(越过长城，走向世界)”，这是中国通过北京与德国大学之间的网络连接，向全球科学网发出的第一封电子邮件。

30年代发展历程

接下来中国的电子邮件进入了30年的发展期，虽然在1987年就有了电子邮件，但是，真正的邮件兴起，应该在90年代到2000年之间，因为在1987的时候中国网速特别慢，真正能接触到互联网的用户是非常少的，到了90年代中期，互联网浏览器的诞生，使得全民上网人数激增，电子邮件被广泛使用，此时，中国的部分学生在研究中使用到电子邮件，真正普及的时间是在2000年左右。

Java发送邮件

Java在发明之初，就开始支持发送邮件，通过java mail包方式去操作邮件发送的内容和协议，但是，这种发送方式稍微比较复杂，需要配置各种参数、协议、内容，之后产生了Spring框架。

Spring发送邮件

Spring在java mail的基础上进行了一些封装，使发送邮件的过程的复杂大大减少。

SpringBoot发送邮件

SpringBoot Mail在Spring Mail的基础上，再次进行一次封装，使得发送邮件的便利度上，更为简单。

电子邮件原理

电子邮件服务器

用户要在Internet上提供电子邮件功能，必须有专门的电子邮件服务器。这些邮件服务器就类似于现实生活中的邮局，它主要负责接收用户投递过来的邮件，并把邮件投递到邮件接收者的电子邮箱中。

邮件服务器就好像是互联网世界的邮局。按照功能划分，邮件服务器可以划分为两种类型：

SMTP邮件服务器：用户替用户发送邮件和接收外面发送给本地用户的邮件。
POP3/IMAP邮件服务器：用户帮助用户读取SMTP邮件服务器接收进来的邮件。

电子邮箱

电子邮箱也称为E-mail地址，用户可以通过E-mail地址来标识自己发送的电子邮件，也可以通过这个地址接收别人发来的电子邮件。电子邮箱需要到邮件服务器进行申请，也就是说，电子邮箱其实就是用户在邮件服务器上申请的账户。邮件服务器会把接收到的邮件保存到为该账户所分配的邮箱空间中，用户通过用户名密码登录到邮件服务器查收该地址已经收到的邮件。一般来讲，邮件服务器为用户分配的邮箱空间是有限的。

邮件客户端

我们可以直接在网站上进行邮件收发，也可以使用常见的FoxMail、Outlook等邮件客户端软件接受邮件。邮件客户端软件通常集邮件撰写、发送和收发功能于一体，主要用于帮助用户将邮件发送给SMTP邮件服务器和从POP3/IMAP邮件服务器读取用户的电子邮件。

邮件传输协议

电子邮件需要在邮件客户端和邮件服务器之间，以及两个邮件服务器之间进行邮件传递，那就必须要遵守一定的规则，这个规则就是邮件传输协议。下面我们分别简单介绍几种协议：

SMTP协议：全称为 Simple Mail Transfer Protocol，简单邮件传输协议。它定义了邮件客户端软件和SMTP邮件服务器之间，以及两台SMTP邮件服务器之间的通信规则。
POP3协议：全称为 Post Office Protocol，邮局协议。它定义了邮件客户端软件和POP3邮件服务器的通信规则。
IMAP协议：全称为 Internet Message Access Protocol,Internet消息访问协议，它是对POP3协议的一种扩展，也是定义了邮件客户端软件和IMAP邮件服务器的通信规则。

邮件格式

要想各种邮件处理程序能识别我们所写的电子邮件，能从我们所书写的电子邮件中分析和提取出发件人、收件人、邮件主题和邮件内容以及附件等信息，那么我们所写的电子邮件必须要遵循一定的格式要求，而这种邮件内容的基本格式和具体细节分别是由 RFC822 文档和 MIME 协议定义的。

RFC822 文档中定义的文件格式包括两个部分：邮件头和邮件体。
MIME协议(Multipurpose Internet Mail Extensions )用于定义复杂邮件体的格式，它可以表达多段平行的文本内容和非文本的邮件内容，例如，在邮件体中内嵌的图像数据和邮件附件等。另外，MIME协议的数据格式也可以避免邮件内容在传输过程中发生信息丢失。MIME协议不是对RFC822邮件格式的升级和替代，而是基于RFC822邮件格式的扩展应用。一言以蔽之，RFC822定义了邮件内容的格式和邮件头字段的详细细节，MIME协议则是定义了如何在邮件体部分表达出的丰富多样的数据内容。

电子邮件发送和接收流程

图示的六个步骤分别进行如下的说明：

①用户A的电子邮箱为：xx@qq.com，通过邮件客户端软件写好一封邮件，交到QQ的邮件服务器，这一步使用的协议是SMTP,对应图示的①；

②QQ邮箱会根据用户A发送的邮件进行解析，也就是根据收件地址判断是否是自己管辖的账户，如果收件地址也是QQ邮箱，那么会直接存放到自己的存储空间。这里我们假设收件地址不是QQ邮箱，而是163邮箱，那么QQ邮箱就会将邮件转发到163邮箱服务器，转发使用的协议也是SMTP，对应图示的②；

③163邮箱服务器接收到QQ邮箱转发过来的邮件，也会判断收件地址是否是自己，发现是自己的账户，那么就会将QQ邮箱转发过来的邮件存放到自己的内部存储空间，对应图示的③；

④用户A将邮件发送了之后，就会通知用户B去指定的邮箱收取邮件。用户B会通过邮件客户端软件先向163邮箱服务器请求，要求收取自己的邮件，对应图示的④；

⑤163邮箱服务器收到用户B的请求后，会从自己的存储空间中取出B未收取的邮件，对应图示⑤；

⑥163邮箱服务器取出用户B未收取的邮件后，将邮件发给用户B，对应图示的⑥；最后三步用户B收取邮件的过程，使用的协议是POP3;

电子邮件的使用场景

在系统中电子邮件的使用场景：

注册验证
营销推送
触发机制
监控报警

电子邮件是业务和安全的最后一道防线 —— 当系统无法自动处理的时候，通过邮件提醒相关支持人员。

SpringBoot实现发送电子邮件

准备账号

注册发件邮箱并设置客户端授权码，这里以163免费邮箱为例：

构建项目并配置

搭建完项目以后，进行下面的两步配置。

application.properties配置参数：

# 邮箱配置
spring.mail.host=smtp.163.com
# 你的163邮箱
spring.mail.username=ispringboot@163.com
# 注意这里不是邮箱密码，而是SMTP授权密码
spring.mail.password=isb001
spring.mail.port=25
spring.mail.protocol=smtp
spring.mail.default-encoding=UTF-8

pom.xml依赖spring-boot-starter-mail模块：

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

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

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

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>

实现服务端代码

MailService.java:

package org.ijiangtao.tech.spring.boot.mail.imail.service;

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;

@Service
public class MailService {

<span class="token keyword">private</span> <span class="token keyword">final</span> Logger logger <span class="token operator">=</span> LoggerFactory<span class="token punctuation">.</span><span class="token function">getLogger</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">getClass</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${spring.mail.username}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String from<span class="token punctuation">;</span><span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> JavaMailSender mailSender<span class="token punctuation">;</span><span class="token comment">/*** 简单文本邮件* @param to 接收者邮件* @param subject 邮件主题* @param contnet 邮件内容*/</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendSimpleMail</span><span class="token punctuation">(</span>String to<span class="token punctuation">,</span> String subject<span class="token punctuation">,</span> String contnet<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>SimpleMailMessage message <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">SimpleMailMessage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>message<span class="token punctuation">.</span><span class="token function">setTo</span><span class="token punctuation">(</span>to<span class="token punctuation">)</span><span class="token punctuation">;</span>message<span class="token punctuation">.</span><span class="token function">setSubject</span><span class="token punctuation">(</span>subject<span class="token punctuation">)</span><span class="token punctuation">;</span>message<span class="token punctuation">.</span><span class="token function">setText</span><span class="token punctuation">(</span>contnet<span class="token punctuation">)</span><span class="token punctuation">;</span>message<span class="token punctuation">.</span><span class="token function">setFrom</span><span class="token punctuation">(</span>from<span class="token punctuation">)</span><span class="token punctuation">;</span>mailSender<span class="token punctuation">.</span><span class="token function">send</span><span class="token punctuation">(</span>message<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token comment">/*** HTML 文本邮件* @param to 接收者邮件* @param subject 邮件主题* @param contnet HTML内容* @throws MessagingException*/</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendHtmlMail</span><span class="token punctuation">(</span>String to<span class="token punctuation">,</span> String subject<span class="token punctuation">,</span> String contnet<span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span>MimeMessage message <span class="token operator">=</span> mailSender<span class="token punctuation">.</span><span class="token function">createMimeMessage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>MimeMessageHelper helper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MimeMessageHelper</span><span class="token punctuation">(</span>message<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setTo</span><span class="token punctuation">(</span>to<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setSubject</span><span class="token punctuation">(</span>subject<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setText</span><span class="token punctuation">(</span>contnet<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setFrom</span><span class="token punctuation">(</span>from<span class="token punctuation">)</span><span class="token punctuation">;</span>mailSender<span class="token punctuation">.</span><span class="token function">send</span><span class="token punctuation">(</span>message<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token comment">/*** 附件邮件* @param to 接收者邮件* @param subject 邮件主题* @param contnet HTML内容* @param filePath 附件路径* @throws MessagingException*/</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendAttachmentsMail</span><span class="token punctuation">(</span>String to<span class="token punctuation">,</span> String subject<span class="token punctuation">,</span> String contnet<span class="token punctuation">,</span>String filePath<span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span>MimeMessage message <span class="token operator">=</span> mailSender<span class="token punctuation">.</span><span class="token function">createMimeMessage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>MimeMessageHelper helper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MimeMessageHelper</span><span class="token punctuation">(</span>message<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setTo</span><span class="token punctuation">(</span>to<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setSubject</span><span class="token punctuation">(</span>subject<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setText</span><span class="token punctuation">(</span>contnet<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setFrom</span><span class="token punctuation">(</span>from<span class="token punctuation">)</span><span class="token punctuation">;</span>FileSystemResource file <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">FileSystemResource</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">File</span><span class="token punctuation">(</span>filePath<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>String fileName <span class="token operator">=</span> file<span class="token punctuation">.</span><span class="token function">getFilename</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">addAttachment</span><span class="token punctuation">(</span>fileName<span class="token punctuation">,</span> file<span class="token punctuation">)</span><span class="token punctuation">;</span>mailSender<span class="token punctuation">.</span><span class="token function">send</span><span class="token punctuation">(</span>message<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token comment">/*** 图片邮件* @param to 接收者邮件* @param subject 邮件主题* @param contnet HTML内容* @param rscPath 图片路径* @param rscId 图片ID* @throws MessagingException*/</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendInlinkResourceMail</span><span class="token punctuation">(</span>String to<span class="token punctuation">,</span> String subject<span class="token punctuation">,</span> String contnet<span class="token punctuation">,</span>String rscPath<span class="token punctuation">,</span> String rscId<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>logger<span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"发送静态邮件开始: {},{},{},{},{}"</span><span class="token punctuation">,</span> to<span class="token punctuation">,</span> subject<span class="token punctuation">,</span> contnet<span class="token punctuation">,</span> rscPath<span class="token punctuation">,</span> rscId<span class="token punctuation">)</span><span class="token punctuation">;</span>MimeMessage message <span class="token operator">=</span> mailSender<span class="token punctuation">.</span><span class="token function">createMimeMessage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>MimeMessageHelper helper <span class="token operator">=</span> null<span class="token punctuation">;</span><span class="token keyword">try</span> <span class="token punctuation">{<!-- --></span>helper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MimeMessageHelper</span><span class="token punctuation">(</span>message<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setTo</span><span class="token punctuation">(</span>to<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setSubject</span><span class="token punctuation">(</span>subject<span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setText</span><span class="token punctuation">(</span>contnet<span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">setFrom</span><span class="token punctuation">(</span>from<span class="token punctuation">)</span><span class="token punctuation">;</span>FileSystemResource res <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">FileSystemResource</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">File</span><span class="token punctuation">(</span>rscPath<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>helper<span class="token punctuation">.</span><span class="token function">addInline</span><span class="token punctuation">(</span>rscId<span class="token punctuation">,</span> res<span class="token punctuation">)</span><span class="token punctuation">;</span>mailSender<span class="token punctuation">.</span><span class="token function">send</span><span class="token punctuation">(</span>message<span class="token punctuation">)</span><span class="token punctuation">;</span>logger<span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"发送静态邮件成功!"</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">MessagingException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>logger<span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"发送静态邮件失败: "</span><span class="token punctuation">,</span> e<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token punctuation">}</span>

}

新建邮件模板

我们使用thymeleaf作为模板引擎。

emailTeplate.html：

<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head><meta charset="UTF-8"/><meta name="viewport"content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"/><meta http-equiv="X-UA-Compatible" content="ie=edge"/><title>注册-测试邮件模板</title>
</head>
<body>你好，感谢你的注册，这是一封验证邮件，请点击下面的连接完成注册，感谢您的支持。<a href="#" th:href="@{https://github.com/{id}(id=${id})}">激活账户</a>
</body>
</html>

测试发送邮件

测试发送邮件，使用单元测试MailServiceTest.java：

package org.ijiangtao.tech.spring.boot.mail.imail.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;

import javax.annotation.Resource;
import javax.mail.MessagingException;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {

<span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> MailService mailService<span class="token punctuation">;</span><span class="token annotation punctuation">@Resource</span>
<span class="token keyword">private</span> TemplateEngine templateEngine<span class="token punctuation">;</span><span class="token annotation punctuation">@Test</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendSimpleMail</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>mailService<span class="token punctuation">.</span><span class="token function">sendSimpleMail</span><span class="token punctuation">(</span><span class="token string">"ispringboot@163.com"</span><span class="token punctuation">,</span><span class="token string">"测试spring boot imail-主题"</span><span class="token punctuation">,</span><span class="token string">"测试spring boot imail - 内容"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token annotation punctuation">@Test</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendHtmlMail</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span>String content <span class="token operator">=</span> <span class="token string">"&lt;html&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;h3&gt;hello world&lt;/h3&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;h1&gt;html&lt;/h1&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;/html&gt;\n"</span><span class="token punctuation">;</span>mailService<span class="token punctuation">.</span><span class="token function">sendHtmlMail</span><span class="token punctuation">(</span><span class="token string">"ispringboot@163.com"</span><span class="token punctuation">,</span><span class="token string">"这是一封HTML邮件"</span><span class="token punctuation">,</span>content<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token annotation punctuation">@Test</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendAttachmentsMail</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span>String filePath <span class="token operator">=</span> <span class="token string">"/ijiangtao/软件开发前景.docx"</span><span class="token punctuation">;</span>String content <span class="token operator">=</span> <span class="token string">"&lt;html&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;h3&gt;hello world&lt;/h3&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;h1&gt;html&lt;/h1&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;h1&gt;附件传输&lt;/h1&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;\n"</span> <span class="token operator">+</span><span class="token string">"&lt;/html&gt;\n"</span><span class="token punctuation">;</span>mailService<span class="token punctuation">.</span><span class="token function">sendAttachmentsMail</span><span class="token punctuation">(</span><span class="token string">"ispringboot@163.com"</span><span class="token punctuation">,</span><span class="token string">"这是一封HTML邮件"</span><span class="token punctuation">,</span>content<span class="token punctuation">,</span> filePath<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token annotation punctuation">@Test</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">sendInlinkResourceMail</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span><span class="token comment">//TODO 改为本地图片目录</span>String imgPath <span class="token operator">=</span> <span class="token string">"/ijiangtao/img/blob/dd9899b4cf95cbf074ddc4607007046c022564cb/blog/animal/dog/dog-at-work-with-computer-2.jpg?raw=true"</span><span class="token punctuation">;</span>String rscId <span class="token operator">=</span> <span class="token string">"admxj001"</span><span class="token punctuation">;</span>String content <span class="token operator">=</span> <span class="token string">"&lt;html&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;h3&gt;hello world&lt;/h3&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;h1&gt;html&lt;/h1&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;h1&gt;图片邮件&lt;/h1&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;img src='cid:"</span><span class="token operator">+</span>rscId<span class="token operator">+</span><span class="token string">"'&gt;&lt;/img&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;body&gt;"</span> <span class="token operator">+</span><span class="token string">"&lt;/html&gt;"</span><span class="token punctuation">;</span>mailService<span class="token punctuation">.</span><span class="token function">sendInlinkResourceMail</span><span class="token punctuation">(</span><span class="token string">"ispringboot@163.com"</span><span class="token punctuation">,</span><span class="token string">"这是一封图片邮件"</span><span class="token punctuation">,</span>content<span class="token punctuation">,</span> imgPath<span class="token punctuation">,</span> rscId<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token annotation punctuation">@Test</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testTemplateMailTest</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> MessagingException <span class="token punctuation">{<!-- --></span>Context context <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Context</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>context<span class="token punctuation">.</span><span class="token function">setVariable</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">,</span><span class="token string">"ispringboot"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>String emailContent <span class="token operator">=</span> templateEngine<span class="token punctuation">.</span><span class="token function">process</span><span class="token punctuation">(</span><span class="token string">"emailTeplate"</span><span class="token punctuation">,</span> context<span class="token punctuation">)</span><span class="token punctuation">;</span>mailService<span class="token punctuation">.</span><span class="token function">sendHtmlMail</span><span class="token punctuation">(</span><span class="token string">"ispringboot@163.com"</span><span class="token punctuation">,</span><span class="token string">"这是一封HTML模板邮件"</span><span class="token punctuation">,</span>emailContent<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span>

}

测试结果，收到了电子邮件：

总结

在生产环境，一般邮件服务会单独部署，并通过HTTP或MQ等方式暴露出来。

springboot实现发邮件