Email Manager (MERN stack)

A management system for maintaining an email address list and sending bulk emails.

Features

1. Sign up requires an "ensure code" (default: goldluck, set via SIGNUP_CODE env var).
2. Add/remove email addresses individually or in bulk via CSV upload.
3. Duplicate addresses are rejected on add and skipped on CSV import (unique index + explicit check).
4. Send emails automatically to a selectable range of addresses (e.g. address #1 to #50), via Gmail SMTP (Nodemailer).
5. Daily statistics: number of emails successfully sent per day.
6. Editable email content (subject/body) and "from" display name via the Settings page.

Setup

1. MongoDB

Have a MongoDB instance running locally or use MongoDB Atlas. Put its connection string in backend/.env.

2. Gmail App Password

Because sending uses Gmail SMTP, you need a Google Account App Password (regular passwords won't work with SMTP):

1. Enable 2-Step Verification on the Gmail account: https://myaccount.google.com/security
2. Create an App Password: https://myaccount.google.com/apppasswords
3. Put the Gmail address and the 16-character app password into backend/.env.

Note: Gmail SMTP sends as the authenticated account. The "From name" you set in the app changes the display name recipients see, but a fully different "from" email address only works if it's configured as a verified "Send As" alias in Gmail settings.

3. Backend

cd backend
cp .env.example .env   # then edit .env with your real values
npm install
npm run dev             # or: npm start

Runs on http://localhost:5000

4. Frontend

cd frontend
cp .env.example .env
npm install
npm start

Runs on http://localhost:3000

Deploying on Render

The root render.yaml defines a Render web service for the API and a static site for the React app.

1. Create a MongoDB Atlas cluster and database user. Allow access from Render in Atlas Network Access, then copy the cluster connection string for the API's MONGO_URI.
2. Push this project to a Git repository and connect that repository to Render using New + > Blueprint.
3. During Blueprint setup, provide MONGO_URI, GMAIL_USER, and a newly created GMAIL_APP_PASSWORD. Render generates JWT_SECRET and SIGNUP_CODE.
4. Deploy both services. The frontend's API URL is wired to the backend service by the Blueprint.

Never commit .env files. If a credential has been exposed, revoke it and use a replacement in Render's environment settings.

Using it

1. Go to /signup, create an account with the ensure code (goldluck by default).
2. Go to Addresses — add addresses one by one, or upload a CSV (any CSV with email-looking values in any column works; a plain one-column list is fine too).
3. Go to Settings to set a default from-name, subject and body.
4. Go to Send — pick a number range (based on each address's position/#, shown in the Addresses table) and send.
5. Go to Stats to see emails sent per day.

CSV format

Any CSV works as long as email addresses appear somewhere in the file — with a header row, without one, or spread across columns. The importer scans every cell and picks out anything that looks like a valid email address, de-duplicating against what's already stored.

Notes / things you may want to extend

• Sending is done synchronously in a loop; for large lists (thousands+) you'd want a queue (e.g. Bull/Redis) to avoid request timeouts and Gmail's sending rate limits (Gmail personal accounts cap around 500 emails/day).
• No password-reset flow yet.
• No rich text editor for the body (plain HTML textarea) — could add TinyMCE/Quill.
• Range selection is based on each address's sequential #, not a live-selection checklist across pages — easy to extend to "select all filtered" style if needed.