MY_EMAIL = "myself@my-TLD.com"
MY_EMAIL_B64 = "base64-encoded-email"
EMAIL_PASSWORD_B64 = "base64-encoded-password"

SMTP_SERVER = "my-ISPs-server"
SMTP_PORT = 25

mail_to = "myself@my-TLD.com"

SSID = "xxxxxxxxxxxxx"
SSID_PASSWORD = "xxxxxxxxxxxxx"

email_subject = ""
email_body = ""
count = 0

smtp_socket = nil

function display(sck,response)
  print(response)
end

function do_next()
  if(count == 0)then
    count = count+1
    local IP_ADDRESS = wifi.sta.getip()
    smtp_socket:send("HELO "..IP_ADDRESS.."\r\n")
  elseif(count==1) then
    count = count+1
    smtp_socket:send("AUTH LOGIN\r\n")
  elseif(count == 2) then
    count = count + 1
    smtp_socket:send(MY_EMAIL_B64.."\r\n")
  elseif(count == 3) then
    count = count + 1
    smtp_socket:send(EMAIL_PASSWORD_B64.."\r\n")
  elseif(count==4) then
    count = count+1
    smtp_socket:send("MAIL FROM:<" .. MY_EMAIL .. ">\r\n")
  elseif(count==5) then
    count = count+1
    smtp_socket:send("RCPT TO:<" .. mail_to ..">\r\n")
  elseif(count==6) then
    count = count+1
    smtp_socket:send("DATA\r\n")
  elseif(count==7) then
    count = count+1
    local message = string.gsub(
      "From: \"".. MY_EMAIL .."\"<"..MY_EMAIL..">\r\n" ..
              "To: \"".. mail_to .. "\"<".. mail_to..">\r\n"..
              "Subject: ".. email_subject .. "\r\n\r\n"  ..
              email_body,"\r\n.\r\n","")

    smtp_socket:send(message.."\r\n.\r\n")
  elseif(count==8) then
    count = count+1
    tmr.stop(0)
    smtp_socket:send("QUIT\r\n")
  else
    smtp_socket:close()
  end
end

function connected(sck)
  tmr.alarm(0,3000,1,do_next)
end

function send_email(subject,body)
  count = 0
  email_subject = subject
  email_body = body
  smtp_socket = net.createConnection(net.TCP,0)
  smtp_socket:on("connection",connected)
  smtp_socket:on("receive",display)
  smtp_socket:connect(SMTP_PORT,SMTP_SERVER)
end

wifi.setmode(wifi.STATION)
wifi.sta.config {ssid=SSID, pwd=SSID_PASSWORD}

tmr.alarm(1, 1000, 1, function()
  if wifi.sta.getip()== nil then
    print("IP unavaiable, Waiting...")
  else
    tmr.stop(1)
    print("Config done, IP is "..wifi.sta.getip())
    send_email(
      "ESP8266",
      [[Hi,
      How are your IoT projects coming along?
      Best Wishes,
      ESP8266]])
  end
end)