package main

import (
    "fmt"
    "net/smtp"
    "strconv"
)

type EmailConfig struct {
    Username string
    Password string
    Host     string
    Port     int
}

func main() {
    // authentication configuration
    smtpHost := "smtp.gmail.com"   // 你可以改为其他的
    smtpPort := 587                // 端口
    smtpPass := "yourpassword"        // 密码
    smtpUser := "youname@gmail.com" // 用户

    emailConf := &EmailConfig{smtpUser, smtpPass, smtpHost, smtpPort}

    emailauth := smtp.PlainAuth("", emailConf.Username, emailConf.Password, emailConf.Host)

    sender := "yourname@gmail.com" // 发送者

    receivers := []string{
        "tosb1@qq.com",  // 收件人1
        "tosb2@qq.com", // 收件人2
    } 

    message := []byte("To: recipient@example.net\r\n" +
        "Subject: discount Gophers!\r\n" +
        "\r\n" +
        "This is the email body. Hello from Go SMTP package.\r\n") // your message

    // send out the email
    err := smtp.SendMail(smtpHost+":"+strconv.Itoa(emailConf.Port), //convert port number from int to string
        emailauth,
        sender,
        receivers,
        message,
    )

    if err != nil {
        fmt.Println(err)
    }
    fmt.Println("well done")
}