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.
Before we begin
List may be incomplete.
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.