Email Systems Deep Dive - Expanded Project Guides

Generated from: EMAIL_SYSTEMS_DEEP_DIVE_PROJECTS.md

This folder contains deep-dive guides for each project in the learning path.

Overview

This series walks through the entire email stack: DNS routing, SMTP state machines, authentication (SPF, DKIM, DMARC), reputation systems, mailbox storage, and client access protocols. Each guide expands the original projects into detailed theory, architecture, and implementation phases with real-world validation steps.

Project Index

# Project Difficulty Time Key Focus
1 Raw SMTP Client from Scratch Intermediate 1-2 weeks SMTP state machine and TLS upgrade
2 MX Record Resolver and Mail Router Intermediate 1-2 weeks DNS packet parsing and MX logic
3 SPF Record Parser and Validator Advanced 2-3 weeks SPF grammar and recursive evaluation
4 DKIM Signature Verifier Expert 3-4 weeks Canonicalization and signature checks
5 DKIM Signer for Outbound Mail Expert 2-3 weeks Signing pipeline and key handling
6 Email Header Analyzer and Route Visualizer Intermediate 1-2 weeks Header parsing and routing forensics
7 Mini SMTP Server (Receive and Store) Advanced 3-4 weeks SMTP server, queues, and storage
8 Bayesian Spam Classifier Advanced 2-3 weeks Statistical filtering and feature design
9 DMARC Policy Engine Advanced 2-3 weeks Alignment rules and policy outcomes
10 Email Reputation and Blacklist Checker Intermediate 1-2 weeks DNSBL lookups and risk scoring
11 POP3 and IMAP Client Intermediate 2-3 weeks Retrieval protocols and state models
12 Open Relay Tester Intermediate 1 week SMTP relay rules and security tests
13 Email Bounce Parser and Categorizer Intermediate 1-2 weeks DSN parsing and failure taxonomy
14 Phishing Email Detector Advanced 2-3 weeks Content signals and spoofing analysis
15 Email Authentication Dashboard Advanced 2-3 weeks Integrated DNS and auth reporting
16 Full Mail Server Stack (Capstone) Master 2-3 months End-to-end mail infrastructure

Prerequisites

  • Comfortable with TCP/IP basics, DNS, and sockets
  • Familiar with command-line tools and basic scripting
  • Able to read RFCs and reason about protocol state machines