send outlook mails using Go

smtp_outlook.go

package main

import (
	"errors"
	"fmt"
	"log"
	"net/smtp"
)

func SendMail(to string) error {

	subject := "Subject: Your Subject Here\n"
	body := "your mail content"
	message := []byte(subject + "\n" + body)

	auth := LoginAuth("yourMailAddress", "yourAppPassword") // not your real password: search creating app password in outlook
	err := smtp.SendMail("smtp-mail.outlook.com:587", auth, "yourMailAddress", []string{to}, message) // "to" variable is a slice for multiple recipients
	if err != nil {
		fmt.Println("Error sending mail: ", err)
		return err
	}

	log.Println("Mail sent successfully")

	return nil
}

type loginAuth struct {
	username, password string
}

func LoginAuth(username, password string) smtp.Auth {
	return &loginAuth{username, password}
}

func (a *loginAuth) Start(server *smtp.ServerInfo) (string, []byte, error) {
	return "LOGIN", []byte(a.username), nil
}

func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
	if more {
		switch string(fromServer) {
		case "Username:":
			return []byte(a.username), nil
		case "Password:":
			return []byte(a.password), nil
		default:
			return nil, errors.New("unkown fromServer")
		}
	}
	return nil, nil
}

func main() {
	SendMail("recipient_mail")
}

/*

recommended: include all variables in .env file

ofc you should customize the content and subject as you like.

based on: https://gist.github.com/homme/22b457eb054a07e7b2fb which is based on https://gist.github.com/andelf/5118732

*/