Golang open smtp relay

In this code I show how to send an Email using Go though an open SMTP relay. No auth, no SSL/TLS, no StartTLS.

This is modified code from https://pkg.go.dev/net/smtp

package main

/*
This program send an email though an open, unecrypted SMTP relay.
*/

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

func main() {
        //Construct email https://pkg.go.dev/net/smtp
        to := "me@example.com"
        from := "go-alert@example.com"
        subject := "This is an example email from golang"
        body := "This email does not use SSL/TLS or StartTLS"
        smtpServer := "smtp.example.com"
        port := "25"

        //Formate email
        server := fmt.Sprintf("%s:%s", smtpServer, port)
        message := []byte(fmt.Sprintf("To: %s\r\nSubject: %s\r\n\r\n%s\r\n", to, subject, body))

        // Connect to the remote SMTP server.
        c, err := smtp.Dial(server)
        if err != nil {
                log.Fatal(err)
        }

        // Set the sender and recipient first
        if err := c.Mail(from); err != nil {
                log.Fatal(err)
        }
        if err := c.Rcpt(to); err != nil {
                log.Fatal(err)
        }

        // Send the email body.
        wc, err := c.Data()
        if err != nil {
                log.Fatal(err)
        }
        _, err = wc.Write(message)
        if err != nil {
                log.Fatal(err)
        }
        err = wc.Close()
        if err != nil {
                log.Fatal(err)
        }

        // Send the QUIT command and close the connection.
        err = c.Quit()
        if err != nil {
                log.Fatal(err)
        }

}

You can also view this over on Github at https://github.com/Jamous/Golang_smtp_relay