Project 02 / 13 · Automation / Cloud / Web

SLTC LMS Email Alert System

A voluntary university email signup and alert distribution service for a shared SLTC LMS calendar monitor, built with Google Apps Script, Google Sheets, GitHub Pages and Cloudflare Turnstile.

Google Apps ScriptGoogle Sheets APIJavaScriptHTML5Cloudflare

Live application Source code on GitHub

The project.

SLTC LMS Email Alert System is an automated university student community service that bridges academic LMS calendar deadlines with students’ inboxes. It eliminates missed assignments and deadline surprises through automated shared-calendar monitoring.

The system features a clean, responsive front-end hosted on GitHub Pages that enables students to subscribe using their verified @sltc.ac.lk university emails. Google Apps Script and HTMLService power the backend subscription engine, using a secure Google Sheet as the subscriber datastore.

Security and reliability safeguards include single-use expiring confirmation links, signed instant-unsubscribe tokens, client-side Turnstile verification, request rate limiting, daily abuse caps, and a durable retry queue with revision deduplication to prevent duplicate notifications.

What it does.

Automated Calendar Monitor

Checks shared university LMS calendar updates every 15 minutes and queues scheduled event alerts.

Verified Student Subscriptions

Enforces strict @sltc.ac.lk email validation with one-click expiring confirmation tokens.

Privacy & Anti-Abuse Safeguards

Zero tracking or marketing, signed one-click unsubscribe links, and optional Cloudflare Turnstile bot protection.

Resilient Delivery Engine

Features quota deferral, retry queues, and event revision deduplication via Google Apps Script and Sheets datastore.

How it comes together.

Front-End Delivery → GitHub Pages serves the mobile-friendly subscriber interface with real-time validation.

Backend Automation → Google Apps Script HTMLService handles tokenized confirmation links and unsubscribe workflows.

Data & Dispatch Layer → Private Google Sheet acts as the subscriber database feeding the durable dispatch monitor.

A closer look.

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