Sending email in GO using Smtp API

package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"net/http"
)

func main() {
	// setup.
	url := "https://api.turbo-smtp.com/api/v2/mail/send"
	consumerkey := "<CONSUMER_KEY>"
	consumerSecret := "<CONSUMER_SECRET>"	

	// Body Data.
	data := []byte(`{
		"from": "hello@your-company.com",
		"to": "Doe.Jhon@gmail.com,contact@global-travel.com",
		"subject": "New live training session",
		"cc": "cc_user@example.com",
		"bcc": "bcc_user@example.com",
		"content": "Dear partner,\nWe are delighted to invite you to an exclusive training session on UX Design. This session is designed to provide essential insights and practical strategies to enhance your skills.",
		"html_content": "Dear partner,\nWe are delighted to invite you to an exclusive training session on <strong>UX Design</strong>. This session is designed to provide essential insights and practical strategies to enhance your skills."
		}`)

	// Create POST Resquest.
	req, err := http.NewRequest("POST", url, bytes.NewBuffer(data))
	if err != nil {
		fmt.Println("An Error has occured:", err)
		return
	}

	// Set Request Headers.
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("accept", "application/json")
	req.Header.Set("consumerKey", consumerkey)
	req.Header.Set("consumerSecret", consumerSecret)		

	// Perform HTTP Request.
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		fmt.Println("An Error has occured sending the request:", err)
		return
	}
	defer resp.Body.Close()

	// Read Server Response
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		fmt.Println("An Error has occured reading the server response:", err)
		return
	}

	// Print Server Response
	fmt.Println(string(body))
}