const net = require('net')

const assert = require('assert')

const host = 'smtp.163.com',

      port = 25,

      user = 'zhangjunyi199616@163.com',

      pass = '*********',

      to = '442665319@qq.com',

      subject = '少林武当大叮当',

      msg = `你好，张啊咩同学，我是一封来自node的邮件

      爱你哟123

      `

let client = net.createConnection({host,port},async() => {

    console.log('连接上了')

    let code

    code = await getData()

    assert(code == 220)

    // 打招呼

    sendData('HELO ' + host)

    code = await getData()

    assert(code == 250)

    // 要登陆

    sendData('auth login')

    code = await getData()

    assert(code == 334)

    // 给用户名（邮箱）---base64编码

    sendData(new Buffer(user).toString('base64'))

    code = await getData()

    assert(code == 334)

    // 给密码---base64编码

    sendData(new Buffer(pass).toString('base64'))

    code = await getData()

    assert(code == 235)

    // 给用户名（邮箱

    sendData(`MAIL FROM:<${user}>`)

    code = await getData()

    assert(code == 250)

    // 给目标邮箱

    sendData(`RCPT TO:<${to}>`)

    code = await getData()

    assert(code == 250)

    // 要发送数据

    sendData('DATA')

    code = await getData()

    assert(code == 354)

    // 发主题

    sendData(`SUBJECT:${subject}`)

    // 发发件人

    sendData(`FROM:${user}`)

    // 发目标

    sendData(`TO:${to}\r\n`)

    sendData(`${msg}\r\n.`)

    code = await getData()

    sendData(`QUIT`)

})

function getData() {

    return new Promise((resolve,reject) => {

        next()

        function next(){

            if(data) {

                let temp = data

                data =null

                resolve(temp)

            } else {

                setTimeout(next,0)

            }

        }

    })

}

function sendData(msg) {

    console.log('发送：'+msg)

    client.write(msg+'\r\n')

}

let data = null

client.on('data', d => {

    console.log('接受到：'+d.toString())

    data = d.toString().substring(0,3)

})

client.on('end', () => {

    console.log('连接断开')

})

连接上了

接受到：220 163.com Anti-spam GT for Coremail System (163com[20141201])

发送：HELO smtp.163.com

接受到：250 OK

发送：auth login

接受到：334 dXNlcm5hbWU6

发送：emhhbmdqdW55aTE5OTYxNkAxNjMuY29t

接受到：334 UGFzc3dvcmQ6

发送：emhhbmc4NjQ3NzY2MA==

接受到：235 Authentication successful

发送：MAIL FROM:<zhangjunyi199616@163.com>

接受到：250 Mail OK

发送：RCPT TO:<@qq.com>

接受到：250 Mail OK

发送：DATA

接受到：354 End data with <CR><LF>.<CR><LF>

发送：SUBJECT:少林武当大叮当

发送：FROM:zhangjunyi199616@163.com

发送：TO:442665319@qq.com

发送：你好，张啊咩同学，我是一封来自node的邮件

      爱你哟123

.

接受到：250 Mail OK queued as smtp7,C8CowAC3Xh8MErdaVr+lLw--.64772S2 1521947148

发送：QUIT

接受到：221 Bye

连接断开