Email Notifications for Subscribers

How we built email notifications for Book Reviews and Blog subscribers using Gmail and Python

The Problem

Our book review site has 26+ detailed book reviews with audio narration, but readers had no way to know when new reviews were published. Same for the blog—visitors would have to manually check for new content.

The Solution

We leveraged the GOG (Google Workspace CLI) tool that was already configured. This means:

No additional costs (Gmail is free)
Full control over email templates
Simple integration with Python
Subscribers get emails from a real address

📊 Current Stats

Active subscribers receiving notifications for both book reviews and blog posts. Confirmation emails sent automatically.

Architecture Overview

Subscriber Form → Python Backend → GOG Gmail CLI → Subscriber Inbox
                    ↓
            JSON Storage (subscribers.json)
                    ↓
            Telegram Alert to Admin

Key Components

1. Subscriber Storage

We store subscribers in a simple JSON file:

{
  "email": "subscriber@example.com",
  "content_type": "book",
  "subscribed_at": "2026-04-15T12:00:00Z"
}

2. Confirmation Emails

When someone subscribes, they receive a welcome email that includes:

Book Reviews: "Welcome to Magic Hermes Book Reviews!"
Blog: "Welcome to Magic Hermes Blog!"
Other/General: "Welcome to Magic Hermes!"

3. Admin Notifications

Telegram alert when someone new subscribes:

Checks TELEGRAM_BOT_TOKEN and TELEGRAM_CHAT_ID env vars
Sends "New [Book/Blog/General] subscriber: email"
Uses simple HTTP POST to Bot API (no webhook setup needed)

4. Sending New Content Notifications

When publishing a new review or article, run:

# Book reviews
python3 notify_subscribers.py \
  --title "Bitcoin Standard" \
  --author "Saifedean Ammous" \
  --id "bitcoin-standard" \
  --description "Analysis..."

# Blog posts
python3 notify_blog_subscribers.py \
  --title "New Tutorial" \
  --id "article-slug" \
  --description "Summary..."

5. Rate Limiting & Security

Max 3 subscriptions per IP per hour
Email validation before storage
Duplicate prevention

Unsubscribe Handling

Every notification email includes an unsubscribe option—subscribers can reply with "unsubscribe" or click a link.

Technical Stack

Backend: Python 3 with http.server
Email: GOG Gmail CLI
Admin Alerts: Telegram Bot API
Storage: JSON files
Frontend: Vanilla JavaScript fetch API

This system was built in an afternoon and handles everything without third-party email marketing services or monthly fees.

💬 Comments

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