This is a simple and efficient backend server built with Node.js and Express. Its primary purpose is to handle the contact form submissions from the portfolio frontend, sending emails via SMTP using Nodemailer.

✨ Features

Email Service: Securely sends emails from the contact form.
Input Validation: Ensures required fields (name, email, message) are present and the email format is valid.
CORS Enabled: Configured with CORS to only accept requests from the frontend application.
Specific Error Handling: Returns structured error keys for different SMTP and server issues, allowing the frontend to display translated, user-friendly messages.
Health Check: Includes a /api/health endpoint to easily verify if the server is running.

🛠️ Tech Stack

Runtime: Node.js
Framework: Express.js
Email: Nodemailer
Environment Variables: Dotenv
Cross-Origin Requests: CORS

🚀 Getting Started

Prerequisites

Node.js (v18 or later)
npm

Installation & Setup

Navigate to the backend directory:
```
cd backend
```
Install dependencies:
```
npm install
```

Create an environment file: Create a file named .env in the backend directory and populate it with your credentials. Do not commit this file to version control.

.env.example

# The port for the backend server
BACKEND_PORT=3001

# Your frontend URL for CORS
FRONTEND_URL=http://localhost:3000

# Nodemailer SMTP Configuration
SMTP_HOST=smtp.example.com
SMTP_PORT=587
SMTP_SECURE=false
SMTP_USER=your-email@example.com
SMTP_PASS=your-email-password
YOUR_RECEIVING_EMAIL=your-personal-email@example.com

Run the server:
```
npm start
```
The server will start on the port defined in your .env file (e.g., 3001).

📝 API Endpoints

Health Check

GET /api/health
- Description: Checks the server status.
- Success Response (200):
```
{ "status": "UP", "message": "Backend is running" }
```

Send Email

POST /api/email/send
- Description: Processes and sends a contact form submission.
- Request Body:
```
{
  "name": "string",
  "email": "string",
  "message": "string"
}
```
- Success Response (200):
```
{ "message": "Message sent successfully!" }
```
- Error Responses (4xx/5xx): Returns a JSON object with an errorKey for the frontend to translate.
```
{ "errorKey": "smtp_auth_failed" }
```