步骤一，开启邮箱服务

在邮箱设置里面开启POP3/SMTP/IMAP服务，如图

步骤二，安装nodemailer插件

npm install -save nodemailer

步骤三，构造如下代码

   const nodemailer=require('nodemailer');

let transporter=nodemailer.createTransport({
    host:'smtp.126.com',
    secure:true,
    auth:{
        user:'*****@126.com',
        pass:'*****'

    },
});

let mailOptions={
    from:'******@126.com',
    to:'******@163.com',
    subject:'天气',
    text:'今天天气很好！',
    html:'<b>今天天气很好！</b>'
};

transporter.sendMail(mailOptions,(err,info)=>{
    if(err){
        console.log(err);
    }
    else{
        console.log(info);
    }
});

步骤四，测试

注意点

发送程序中，subject,和主题需要相一致，不然导致如下错误，504，SUM 信封发件人和信头发件人不匹配

{ Error: Message failed: 554 DT:SPM 126 smtp7,DsmowAA3nqryKy1Zc0oRJw--.15930S2 1496132596,please see http://mail.163.com/help/help_spam_16.htm?ip=111.74.215.148&hostid=smtp7&time=1496132596
    at SMTPConnection._formatError (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:557:19)
    at SMTPConnection._actionSMTPStream (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:1385:34)
    at SMTPConnection._responseActions.push.str (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:907:22)
    at SMTPConnection._processResponse (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:706:20)
    at SMTPConnection._onData (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:509:14)
    at TLSSocket._socket.on.chunk (D:\node\likeread\node_modules\nodemailer\lib\smtp-connection\index.js:461:47)
    at emitOne (events.js:96:13)
    at TLSSocket.emit (events.js:188:7)
    at readableAddChunk (_stream_readable.js:176:18)
    at TLSSocket.Readable.push (_stream_readable.js:134:10)
  code: 'EMESSAGE',
  response: '554 DT:SPM 126 smtp7,DsmowAA3nqryKy1Zc0oRJw--.15930S2 1496132596,please see http://mail.163.com/help/help_spam_16.htm?ip=111.74.215.148&hostid=smtp7&time=1496132596',
  responseCode: 554,
  command: 'DATA' }