1. Turn on “2-Step Verification” so that an “App password” can be generated

2. go get gopkg.in/gomail.v2

3. Send your Email like the example below:

package main

import (
	"gopkg.in/gomail.v2"
)

func main() {
	m := gomail.NewMessage()
	m.SetHeader("From", "[email protected]")
	m.SetAddressHeader("To", "to_adress@xxx", "to_name")
	m.SetAddressHeader("Cc", "cc_adress@xxx", "cc_name")
	m.SetHeader("Subject", "Hello! TEST!")
	m.SetBody("text/html", "Hello! <b>TEST</b>!")

	d := gomail.NewPlainDialer("smtp.gmail.com", 587, "[email protected]", "the App password")

	if err := d.DialAndSend(m); err != nil {
		panic(err)
	}
}