Email Services

Email Services is a Node.js and Express API for testing and sending transactional emails through multiple email providers. The currently wired HTTP routes support SendGrid, Resend, and Brevo. The repository also includes controller or SMTP examples for Mailgun, Postmark, and Nodemailer-based provider setups.

What It Does

• Starts an Express server with JSON request parsing.
• Provides provider-specific email sending endpoints.
• Loads API keys and server configuration from environment variables.
• Keeps each provider's email sending logic in a separate controller file.
• Includes example service files showing SMTP transporter settings for common email providers.

Tech Stack

• Node.js
• Express
• dotenv
• SendGrid SDK
• Resend SDK
• Brevo SDK
• Mailgun SDK
• Postmark SDK
• Nodemailer

Project Structure

.
+-- controllers/       # Email sending logic for each provider
+-- routes/            # Express routes for active provider endpoints
+-- services/          # SMTP transporter examples
+-- server.js          # Express app entry point
+-- package.json       # Scripts and dependencies
+-- .env.example       # Example environment variables
`-- README.md

Getting Started

1. Install Dependencies

npm install

2. Configure Environment Variables

Create a .env file in the project root. You can start by copying .env.example:

cp .env.example .env

On Windows PowerShell:

Copy-Item .env.example .env

Update .env with your real provider keys:

PORT=4000

SENDGRID_API_KEY=your-sendgrid-api-key
RESEND_API_KEY=your-resend-api-key
BREVO_API_KEY=your-brevo-api-key
MAILGUN_API_KEY=your-mailgun-api-key
POSTMARK_API_KEY=your-postmark-api-key

Do not commit .env. It is already ignored by .gitignore.

3. Update Email Details

Before sending real emails, update the placeholder sender and recipient values in the provider controller you want to use:

• controllers/sendgridEmail.js
• controllers/resendEmail.js
• controllers/brevoEmail.js
• controllers/mailgunEmail.js
• controllers/postmarkEmail.js

For example, replace placeholder values such as hello@yourdomain.com, empty to fields, and sample recipient strings with verified sender and recipient email addresses supported by your provider account.

4. Start the Server

For production-style startup:

npm start

For development with automatic restarts:

npm run server

By default, the server runs on:

http://localhost:4000

API Endpoints

Health Check

GET /

Returns a basic JSON response showing that the server is running.

SendGrid

POST /api/sendgrid/send-email

Uses SENDGRID_API_KEY and the email details configured in controllers/sendgridEmail.js.

Resend

POST /api/resend/send-email

Uses RESEND_API_KEY and the email details configured in controllers/resendEmail.js.

Brevo

POST /api/brevo/send-email

Uses BREVO_API_KEY and the email details configured in controllers/brevoEmail.js.

Example Request

The current controllers use hard-coded example email payloads, so the request body is not required yet.

curl -X POST http://localhost:4000/api/resend/send-email

If the provider key and email settings are valid, the server responds with a success message and provider response data where available.

Available Scripts

npm start

Runs the server with Node.

npm run server

Runs the server with Nodemon for development.

npm test

Currently returns the default placeholder test error. No automated tests are configured yet.

Notes

• SendGrid, Resend, and Brevo are currently connected to Express routes.
• Mailgun and Postmark controller files exist, but their routes are not currently mounted in server.js.
• Some files in services/ are SMTP transporter examples and are not imported by the active server code.
• Most email providers require verified sender domains or sender addresses before they allow production email delivery.