通过javamail，用免费阿里云邮箱账号发邮件
环境：Debian9, OpenJDK-8，tomcat-8.5，javamail-1.16.1
过程：
- apt update && apt upgrade && apt autoremove # 更新软件
- apt install openjdk-8-jdk # 安装 openjdk-8
- apt install libservlet3.1-java # 安装 Java Servlet 和 JSP 库
- mkdir -p /var/lib/tomcat8/webapps/ROOT/WEB-INF/lib # 创建测试lib目录
- cd /var/lib/tomcat8/webapps/ROOT/WEB-INF/lib && wget https://github.com/javaee/javamail/releases/download/JAVAMAIL-1_6_1/javax.mail.jar # 下载javamail-1.6.1到lib目录中
vi /var/lib/tomcat8/webapps/ROOT/javamail.jsp # 创建测试发邮件表单 javamail.jsp，内容如下，此例是通过连接smtp.aliyun.com 的 465端口，账户名是 anqunhe@aliyun.com
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8" %> <% //homepage: http://cn.waterlin.org/ request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html; charset=utf-8"); %> <%@ page import="javax.mail.*"%> <%@ page import="javax.mail.internet.*"%> <%@ page import="javax.activation.*"%> <%@ page import="java.util.*,java.io.*"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>JavaMail 电子邮件发送系统</title> </head> <body> <form action="" method="post" OnSubmit=""> 收件人Email:<br /> <input type="text" name="recipients"><br /> 发件人Mail：<br /> <input name="frommail" type="text" size="30" /><br /> 邮件标题 <br /> <input name="subject" type="text" size="50" /><br /> 内容：<br /> <textarea name="contents" cols="50" rows="10"></textarea> <br /> <input type="submit" name="Submit" value="发送邮件" /> <form> <%! //相应的服务器信息 String host = "smtp.aliyun.com"; String user = "anqunhe@aliyun.com"; String password = "密码"; String contentType="text/html; charset=utf-8"; private class Authenticator extends javax.mail.Authenticator { public PasswordAuthentication getPasswordAuthentication() { String un = user; String pw = password; return new PasswordAuthentication(un, pw); } } %> <% String touser = request.getParameter("recipients")!=null ? request.getParameter("recipients") : ""; String fromuser = request.getParameter("frommail")!=null ? request.getParameter("frommail") : ""; String subject = request.getParameter("subject")!=null ? request.getParameter("subject") : ""; String contents = request.getParameter("contents")!=null ? request.getParameter("contents") : ""; try { Properties props = new Properties(); props.put("mail.smtp.auth","true"); //是否验证 props.put("mail.smtp.host", host); props.put("mail.smtp.user", user); props.put("mail.smtp.password",password); props.put("mail.smtp.ssl.enable","true"); props.put("mail.smtp.ssl.enable", "true"); props.put("mail.smtp.port","465");//Gmail 的端口号 //根据邮件服务器是否需要 ttl 验证选用 //props.put("mail.smtp.starttls.enable","true"); boolean sessionDebug = false; Authenticator auth = new Authenticator(); //Session mailSession = Session.getDefaultInstance(props, auth); //有时可能被拒绝 Session mailSession = Session.getInstance(props,auth); //用户验证; //Session mailSession = Session.getInstance(props); //mailSession.setDebug(sessionDebug); Message msg = new MimeMessage(mailSession); msg.setFrom(new InternetAddress( fromuser )); msg.setRecipient(Message.RecipientType.TO, new InternetAddress( touser )); msg.setSubject( "邮件标题：" +subject); //((MimeMessage)msg).setSubject(subject, "GBK"); //设置中文标题 msg.setSentDate(new Date()); String text = contents + "<hr>javamail.jsp 发送认证邮件<b>测试</b>。"; msg.setContent(text, contentType); Transport transport = mailSession.getTransport("smtp"); transport.connect(host,user,password); transport.send( msg ); %> <p>你的邮件已发送，<a href="./javamail.jsp">请返回。</></p> <% } catch (Exception m) { } %> </body> </html>
- 填写好表单，测试发邮件。成功（在垃圾箱中）。
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