Introduction

Chatterbox3000 is a self-hosted email filtering service that sits between incoming mail and your inbox. It intercepts emails via Cloudflare Email Routing, classifies them using heuristic rules, and either auto-forwards them or holds them for manual review.

The Problem

If you publish a contact email anywhere — your website, GitHub profile, domain WHOIS — you’ll get cold outreach, spam, and newsletters mixed in with legitimate mail. Traditional spam filters miss cold outreach because it’s technically not spam.

The Solution

Chatterbox3000 adds an approval layer:

1. Known senders (allowlisted) get forwarded immediately
2. Blocked senders get silently dropped
3. Unknown senders are held in a queue for you to review

You manage everything from a Chrome Extension side panel — approve, reject, or permanently allow/block senders with one click.

Architecture Overview

Sender → MX → Cloudflare Email Routing → Email Worker
                                            ├── Allowed? → Forward immediately
                                            ├── Blocked? → Drop
                                            └── Unknown? → Classify → Queue for review
                                                              ↓
                                                    Chrome Extension (Side Panel)
                                                    ├── Approve → Forward via send_email
                                                    └── Reject → Archive

Tech Stack

Layer	Technology
Email ingress	Cloudflare Email Routing + Workers
API	Cloudflare Workers (Hono)
Database	Cloudflare D1 (SQLite)
ORM	Drizzle ORM
Real-time updates	Durable Objects (WebSocket)
Auth	Shared bearer token
Extension frontend	React + TanStack Router/Query
Extension type	Chrome Side Panel (Manifest V3)