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.
Add this skill
npx mdskills install sickn33/email-systemsCovers email engineering fundamentals but lacks actionable implementation guidance
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.
Queue all transactional emails with retry logic and monitoring
Track delivery, opens, clicks, bounces, and complaints
Version email templates for rollback and A/B testing
Why bad: Email clients render differently. Outlook breaks everything.
Why bad: Some clients strip HTML. Accessibility issues. Spam signal.
Why bad: Images blocked by default. Spam trigger. Slow loading.
| Issue | Severity | Solution |
|---|---|---|
| Missing SPF, DKIM, or DMARC records | critical | # Required DNS records: |
| Using shared IP for transactional email | high | # Transactional email strategy: |
| Not processing bounce notifications | high | # Bounce handling requirements: |
| Missing or hidden unsubscribe link | critical | # Unsubscribe requirements: |
| Sending HTML without plain text alternative | medium | # Always send multipart: |
| Sending high volume from new IP immediately | high | # IP warm-up schedule: |
| Emailing people who did not opt in | critical | # Permission requirements: |
| Emails that are mostly or entirely images | medium | # Balance images and text: |
Install via CLI
npx mdskills install sickn33/email-systemsEmail Systems is a free, open-source AI agent skill. 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.
Install Email Systems with a single command:
npx mdskills install sickn33/email-systemsThis downloads the skill files into your project and your AI agent picks them up automatically.
Email Systems works with Claude Code, Claude Desktop, Cursor, Vscode Copilot, Windsurf, Continue Dev, Codex, Gemini Cli, Amp, Roo Code, Goose, Opencode, Trae, Qodo, Command Code. Skills use the open SKILL.md format which is compatible with any AI coding agent that reads markdown instructions.