/*
 * user : example@example.com login smtp server user
 * password: xxxxx login smtp server password
 * host: smtp.example.com:port   smtp.163.com:25
 * to: example@example.com;example1@163.com;example2@sina.com.cn;...
 *  subject:The subject of mail
 *  body: The content of mail
 *  mailtyoe: mail type html or text
 */

func SendMail(user, password, host, to, subject, body, mailtype string) error{
 hp := strings.Split(host, ":")
 auth := smtp.PlainAuth("", user, password, hp[0])
 var content_type string
 if mailtype == "html" {
  content_type = "Content-Type: text/"+ mailtype + "; charset=UTF-8"
 }else{
  content_type = "Content-Type: text/plain" + "; charset=UTF-8"
 }

 msg := []byte("To: " + to + "\r\nFrom: " + user + ""+ user +">\r\nSubject: " + subject + "\r\n" + content_type + "\r\n\r\n" + body)
 send_to := strings.Split(to, ";")
 err := smtp.SendMail(host, auth, user, send_to, msg)
 return err
}

func main() {
 user := "xxxx@163.com"
 password := "xxxx"
 host := "smtp.163.com:25"
 to := "xxxx@gmail.com;ssssss@gmail.com"

 subject := "Test send email by golang"

 body := `
 html>
 body>
 h3>
 "Test send email by golang"
 /h3>
 /body>
 /html>
 `
 fmt.Println("send email")
 err := SendMail(user, password, host, to, subject, body, "html")
 if err != nil {
  fmt.Println("send mail error!")
  fmt.Println(err)
 }else{
  fmt.Println("send mail success!")
 }
}