Concurrency-first transactional email for Go microservices & backends

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"time"
)

type SendEmailPayload struct {
	From    string   `json:"from"`
	To      string   `json:"to"`
	Subject string   `json:"subject"`
	HTML    string   `json:"html"`
	Tags    []string `json:"tags"`
}

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	payload := SendEmailPayload{
		From:    "alerts@yourdomain.com",
		To:      "developer@example.com",
		Subject: "Worker Deployed: Build #1042",
		HTML:    "<p>Your service is live on port 8080.</p>",
		Tags:    []string{"ci", "deploy"},
	}

	body, _ := json.Marshal(payload)
	req, _ := http.NewRequestWithContext(ctx, "POST", "https://api.sadasend.com/emails", bytes.NewBuffer(body))
	req.Header.Set("Authorization", "Bearer "+os.Getenv("SADASEND_API_KEY"))
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{Timeout: 5 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
	fmt.Printf("Email dispatched! Status: %s\n", resp.Status)
}