Automated Newsletter Broadcasting with Cloudflare Workers

I just finished building an automated newsletter system for this site. Here’s how it works! 🎉

The Problem

Having a newsletter subscription system is great, but manually sending emails every time I publish something? That’s a recipe for forgetting and inconsistency.

I wanted:

1. Automatic blog notifications — When I publish a new post, subscribers get notified
2. Weekly TIL digest — A compilation of everything I learned that week, sent every Sunday

The Solution

The system uses Cloudflare Workers cron triggers to periodically check for new content:

Blog Post Notifications

Every day at 10am UTC, a cron job:

1. Fetches all published blog posts
2. Checks which ones haven’t been emailed yet (tracked in D1 database)
3. Sends personalized emails to all active subscribers
4. Records what was sent to avoid duplicates

Weekly TIL Digest

Every Sunday at 10am UTC:

1. Collects all TILs from the past week
2. Compiles them into a single digest email
3. Sends to all subscribers

Technical Stack

• Cloudflare Workers — Serverless compute for cron jobs
• Cloudflare D1 — SQLite database for subscriber management and sent tracking
• AWS SES — Reliable email delivery with proper authentication
• Astro — Static site generation with server-side API routes

The Email Templates

Each email includes:

• Beautiful HTML version (matching the site’s green garden theme)
• Plain text fallback
• One-click unsubscribe link (RFC 8058 compliant)
• List-Unsubscribe headers for email client support

Good question! Right now it’s all-or-nothing, but granular preferences are on the roadmap. For now, you can always unsubscribe and re-subscribe when you see a post you’re interested in.

What’s Next?

• Granular subscription preferences (blog only, TIL only, etc.)
• Preview emails before sending (admin dashboard)
• Email open/click tracking (privacy-respecting)

If you haven’t already, subscribe below to see the system in action! 🌱