Introduction: ESP8266 GMail Sender

Hello and welcome to my first Instructable.

I will show you how to send emails from any ESP8266 wifi module using Gmail server.

This instructable relies on Arduino core for ESP8266 WiFi chip,

which makes a self-contained microcontroller from it (no need of AT commands and master devices).

You can connect sensors and get notified by email about changes.

2018 Update:

Here is newer code written as arduino lib. It supports multiple recipients.
Also no need to encode login and password to base64 now it uses ESP core base64 lib. github

2019 Update:

  • This code doesn't work with ESP8266 core for Arduino version 2.5.0!
  • Temporary solution use core version 2.4.2


Before we begin

Required hardware:

  1. Any ESP8266 (I'm using ESP8266-07 ebay link).
  2. In my case USB UART Board(I'm using FT232RL FTDI Serials Adapter Module ebay). Not needed if your board has usb port.
  3. Some jumper cables.
  4. WIFI router of course.

List may be incomplete.

Required software:

  1. Arduino Software
  2. Arduino core for ESP8266 WiFi chip
  3. Sketch with project and test code (ESP8266_Gmail_Sender.zip).

Step 1: Gmail Account Setup

We are going to use SMTP to send messages.

Using SMTP Authentication we provide only email and password,

by default Google uses more complex verification methods so we need to change settings.

Go to your Google account settings and enable "Allow less secure apps" at the bottom of the page.

This mean apps only need your email and password when login to your gmail account.

If you concerned about security, just use different account.

Step 2: Edit Sketch

I wrote a little sketch which send one test message to check if all works as should.

When all software downloaded and installed:

  • Unzip ESP8266_Gmail_Sender.zip
  • Find and open ESP8266_Gmail_Sender.ino
  • Set your wifi access point name (SSID) and password. Should be like this:
const char* ssid = "MyWiFi";
const char* password = "12345678";
  • In setup() function find
if(gsender->Subject(subject)->Send("boris.on@live.com", "Setup test"))

First parameter of Send() function is recipient email, second message text.

Change recipient from boris.on@live.com to your email which will receive a message.


I'm receiving many emails every day because some of You guys not attentive, PLEASE DON'T FORGET TO CHANGE RECIPIENT EMAIL!


Subject function is optional! Subject sets once and stored until you change it.

You can send mails without subject or if it already set

gsender->Send(to, message);
  • Now open Gsender.h tab
  • We need Base64 encoded email address and password of gmail account which will be used to send emails.

You can use base64encode.org for encoding, result must be something like:

const char* EMAILBASE64_LOGIN = "Y29zbWkxMTExMUBnbWFpbC5jb20=";
const char* EMAILBASE64_PASSWORD = "TGFzZGFzZDEyMzI=";
  • Now set FROM field.
const char* FROM = "your_email@gmail.com";

That`s all for this part.

Step 3: Code Uploading and Testing

Save changes. Don`t forget to set your board in Tool menu.

Upload sketch to your ESP8266 board.

Open Serial monitor, board will print log messages.

That`s all I hope you will receive "Message send.". Thanks...