A simple to use email wrapper

go-mail.go

package main

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

func SmtpAuthentification(username string, pwd string, host string) smtp.Auth {
	return (smtp.PlainAuth("", username, pwd, host))
}

func SendEmail(auth smtp.Auth, host string, hostPort int, username string, targets []string, ccTo []string, subject string, content string) error {
	destHeader := "To: "
	i := 0
	for _, dest := range targets {
		if i > 1 {
			destHeader = destHeader + ", " + dest
		} else {
			destHeader = destHeader + dest
		}
		i += 1
	}
	destHeader = destHeader + "\r\n"

	i = 0
	ccHeader := "cc: "
	for _, cced := range ccTo {
		if i > 1 {
			ccHeader = ccHeader + ", " + cced
		} else {
			ccHeader = ccHeader + cced
		}
		i += 1
	}
	ccHeader = ccHeader + "\r\n"

	obj := "Subject: " + subject + "\r\n"
	finalContent := content + "\r\n"

	var msg []byte
	if ccTo == nil {
		msg = []byte(destHeader + obj + finalContent)
	} else {
		msg = []byte(destHeader + ccHeader + obj + finalContent)
    targets = append(targets, ccTo...)
	}
	if len(msg) == 0 {
		return fmt.Errorf("Cannot send email with 0 bytes as content")
	}
	smtpHost := host + ":" + strconv.Itoa(hostPort)
	err := smtp.SendMail(smtpHost, auth, username, targets, msg)
	if err != nil {
		fmt.Printf("Error: %s\n", err)
		return fmt.Errorf("Failed to send email with subject [%s] to [%s]", subject, targets[0])
	}
	return nil
}

func main() {
  username := "johndoe"
  smtpHost := "smtp.gmail.com"
  smtpPort := 587
  pwd := "fakepassword"
  
  recipients := []string{"mugiwara@noluffy.cn", "sanji@vinsmoke.fr"}
  ccTo := []string{"roronoa@zoro.jp"}
  subject := "Kaizoku oni ore wa naru"
  content := "Basically means that I'm going to be the pirate king.\r\n Could be powerful if combined with go-template.go (another one of my gists)"
  
  auth := SmtpAuthentification(username, pwd, smtpHost)
  err := SendEmail(auth, smtpHost, smtpPort, username, recipients, ccTo, subject, content)
  if err != nil {
    fmt.Printf("Sending email failed with error: %v", err)
    panic("haaaaaaaaaaaa!")
  }
  fmt.Println("Successfuly sent requested email. Yay!")
}