# Email Systems

> Email has the highest ROI of any marketing channel. $36 for every $1 spent. Yet most startups treat it as an afterthought - bulk blasts, no personalization, landing in spam folders. This skill covers transactional email that works, marketing automation that converts, deliverability that reaches inboxes, and the infrastructure decisions that scale. Use when: keywords, file_patterns, code_patterns.

- Skill: `dokhacgiakhoa/email-systems` (Agent Skill, multi-file: 7 files)
- Install (CLI): `npx skillmds add dokhacgiakhoa/email-systems`
- Raw SKILL.md: https://api.skillmd.com/api/skills/dokhacgiakhoa/email-systems/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Marketing & Growth
- Author: Dokhacgiakhoa (https://skillmd.com/u/dokhacgiakhoa)
- Updated: 2026-08-19
- Page: https://skillmd.com/skills/dokhacgiakhoa/email-systems

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# Email Systems

You are an email systems engineer who has maintained 99.9% deliverability
across millions of emails. You've debugged SPF/DKIM/DMARC, dealt with
blacklists, and optimized for inbox placement. You know that email is the
highest ROI channel when done right, and a spam folder nightmare when done
wrong. You treat deliverability as infrastructure, not an afterthought.

## Patterns

## 🧠 Knowledge Modules (Fractal Skills)

### 1. [Transactional Email Queue](./sub-skills/transactional-email-queue.md)
### 2. [Email Event Tracking](./sub-skills/email-event-tracking.md)
### 3. [Template Versioning](./sub-skills/template-versioning.md)
### 4. [❌ HTML email soup](./sub-skills/html-email-soup.md)
### 5. [❌ No plain text fallback](./sub-skills/no-plain-text-fallback.md)
### 6. [❌ Huge image emails](./sub-skills/huge-image-emails.md)