Email Scheduler Application

A full-stack email scheduling application built with a legacy-style architecture as per requirements.

Tech Stack

• Frontend: React (Vite), Mantine UI, Tailwind CSS.
• Backend: Express.js, MySQL (Sequelize), Redis, BullMQ.
• Testing: Ethereal Email (SMTP).

Features

• Google OAuth Login: Secure login (requires Client ID).
• Email Scheduling: Schedule emails to be sent in the future.
• Persistent Queue: Jobs survive server restarts using Redis & MySQL.
• Rate Limiting: Configurable limits (e.g., 100 emails/hour) with concurrency control.
• Dashboard: View status of scheduled and sent emails.
• Bulk Upload: UI supports mocking CSV upload for bulk scheduling.

Quick Start

Prerequisites

• Docker & Docker Compose
• Node.js (v18+)

Setup

1. Start Infrastructure (MySQL & Redis)

   docker-compose up -d

2. Backend Setup

   cd backend
   npm install
   # Configure .env (see backend/README.md)
   npm run dev

3. Frontend Setup

   cd frontend
   npm install --legacy-peer-deps
   # Configure .env or hardcode ClientID
   npm run dev

4. Access

   • Frontend: http://localhost:3001
   • Backend API: http://localhost:5000

5. Live Links

   • Frontend: https://email-scheduler-1-kiny.onrender.com
   • Backend: https://email-scheduler-co1x.onrender.com

Architecture

The system uses a producer-consumer pattern. The API (Producer) accepts requests and pushes them to a Redis Queue (BullMQ). A Worker (Consumer) processes these jobs, enforcing rate limits and delays, and sends emails via SMTP (Ethereal). State is persisted in both MySQL (long-term records) and Redis (active queue state).