---
name: email-systems
description: "Email Systems workflow skill. Use this skill when the user needs Email has the highest ROI of any marketing channel. $36 for every and the operator should preserve the upstream workflow, copied support files, and provenance before merging or handing off."
version: "0.0.1"
category: devops
tags: ["email-systems", "email", "has", "the", "highest", "roi", "any", "marketing"]
complexity: advanced
risk: caution
tools: ["codex-cli", "claude-code", "cursor", "gemini-cli", "opencode"]
source: community
author: "sickn33"
date_added: "2026-04-14"
date_updated: "2026-04-25"
---

# Email Systems

## Overview

This public intake copy packages `plugins/antigravity-awesome-skills-claude/skills/email-systems` from `https://github.com/sickn33/antigravity-awesome-skills` into the native Omni Skills editorial shape without hiding its origin.

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses the `external_source` block in `metadata.json` plus `ORIGIN.md` as the provenance anchor for review.

# 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.

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Patterns, Sharp Edges, DKIM (DomainKeys Identified Mail), DMARC (Domain-based Message Authentication), Option 1: Dedicated IP (high volume), Option 2: Transactional-only provider.

## When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

- Use this skill when the request clearly matches the capabilities and patterns described above.
- Use when the request clearly matches the imported source intent: Email has the highest ROI of any marketing channel. $36 for every.
- Use when the operator should preserve upstream workflow detail instead of rewriting the process from scratch.
- Use when provenance needs to stay visible in the answer, PR, or review packet.
- Use when copied upstream references, examples, or scripts materially improve the answer.
- Use when the workflow should remain reviewable in the public intake repo before the private enhancer takes over.

## Operating Table

| Situation | Start here | Why it matters |
| --- | --- | --- |
| First-time use | `metadata.json` | Confirms repository, branch, commit, and imported path through the `external_source` block before touching the copied workflow |
| Provenance review | `ORIGIN.md` | Gives reviewers a plain-language audit trail for the imported source |
| Workflow execution | `SKILL.md` | Starts with the smallest copied file that materially changes execution |
| Supporting context | `SKILL.md` | Adds the next most relevant copied source file without loading the entire package |
| Handoff decision | `## Related Skills` | Helps the operator switch to a stronger native skill when the task drifts |

## Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
2. Read the overview and provenance files before loading any copied upstream support files.
3. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.
4. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes.
5. Validate the result against the upstream expectations and the evidence you can point to in the copied files.
6. Escalate or hand off to a related skill when the work moves out of this imported workflow's center of gravity.
7. Before merge or closure, record what was used, what changed, and what the reviewer still needs to verify.

### Imported Workflow Notes

#### Imported: Patterns

### Transactional Email Queue

Queue all transactional emails with retry logic and monitoring

**When to use**: Sending any critical email (password reset, receipts, confirmations)

// Don't block request on email send
await queue.add('email', {
  template: 'password-reset',
  to: user.email,
  data: { resetToken, expiresAt }
}, {
  attempts: 3,
  backoff: { type: 'exponential', delay: 2000 }
});

### Email Event Tracking

Track delivery, opens, clicks, bounces, and complaints

**When to use**: Any email campaign or transactional flow

# Track lifecycle:
- Queued: Email entered system
- Sent: Handed to provider
- Delivered: Reached inbox
- Opened: Recipient viewed
- Clicked: Recipient engaged
- Bounced: Permanent failure
- Complained: Marked as spam

### Template Versioning

Version email templates for rollback and A/B testing

**When to use**: Changing production email templates

templates/
  password-reset/
    v1.tsx (current)
    v2.tsx (testing 10%)
    v1-deprecated.tsx (archived)

# Deploy new version gradually
# Monitor metrics before full rollout

### Bounce Handling State Machine

Automatically handle bounces to protect sender reputation

**When to use**: Processing bounce and complaint webhooks

switch (bounceType) {
  case 'hard':
    await markEmailInvalid(email);
    break;
  case 'soft':
    await incrementBounceCount(email);
    if (count >= 3) await markEmailInvalid(email);
    break;
  case 'complaint':
    await unsubscribeImmediately(email);
    break;
}

### React Email Components

Build emails with reusable React components

**When to use**: Creating email templates

import { Button, Html } from '@react-email/components';

export default function WelcomeEmail({ userName }) {
  return (
    <Html>
      <h1>Welcome {userName}!</h1>
      <Button href="https://app.com/start">
        Get Started
      </Button>
    </Html>
  );
}

### Preference Center

Let users control email frequency and topics

**When to use**: Building marketing or notification systems

Preferences:
☑ Product updates (weekly)
☑ New features (monthly)
☐ Marketing promotions
☑ Account notifications (always)

# Respect preferences in all sends
# Required for GDPR compliance

## Examples

### Example 1: Ask for the upstream workflow directly

```text
Use @email-systems to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.
```

**Explanation:** This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

### Example 2: Ask for a provenance-grounded review

```text
Review @email-systems against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.
```

**Explanation:** Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

### Example 3: Narrow the copied support files before execution

```text
Use @email-systems for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.
```

**Explanation:** This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

### Example 4: Build a reviewer packet

```text
Review @email-systems using the copied upstream files plus provenance, then summarize any gaps before merge.
```

**Explanation:** This is useful when the PR is waiting for human review and you want a repeatable audit packet.



## Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

- Transactional vs Marketing separation | Description: Transactional emails (password reset, receipts) need 100% delivery.
- Permission is everything | Description: Only email people who asked to hear from you. Double opt-in for marketing.
- Deliverability is infrastructure | Description: SPF, DKIM, DMARC are not optional. Warm up new IPs. Monitor bounce rates.
- One email, one goal | Description: Each email should have exactly one purpose and one CTA. Multiple asks
- Timing and frequency matter | Description: Wrong time = low open rates. Too frequent = unsubscribes. Let users
- At least 60% text content
- Images for enhancement, not content

### Imported Operating Notes

#### Imported: Principles

- Transactional vs Marketing separation | Description: Transactional emails (password reset, receipts) need 100% delivery.
Marketing emails (newsletters, promos) have lower priority. Use separate
IP addresses and providers to protect transactional deliverability. | Examples: Good: Password resets via Postmark, marketing via ConvertKit | Bad: All emails through one SendGrid account
- Permission is everything | Description: Only email people who asked to hear from you. Double opt-in for marketing.
Easy unsubscribe. Clean your list ruthlessly. Bad lists destroy deliverability. | Examples: Good: Confirmed subscription + one-click unsubscribe | Bad: Scraped email list, hidden unsubscribe, bought contacts
- Deliverability is infrastructure | Description: SPF, DKIM, DMARC are not optional. Warm up new IPs. Monitor bounce rates.
Deliverability is earned through technical setup and good behavior. | Examples: Good: All DNS records configured, dedicated IP warmed for 4 weeks | Bad: Using free tier shared IP, no authentication records
- One email, one goal | Description: Each email should have exactly one purpose and one CTA. Multiple asks
means nothing gets clicked. Clear single action. | Examples: Good: "Click here to verify your email" (one button) | Bad: "Verify email, check out our blog, follow us on Twitter, refer a friend..."
- Timing and frequency matter | Description: Wrong time = low open rates. Too frequent = unsubscribes. Let users
set preferences. Test send times. Respect inbox fatigue. | Examples: Good: Weekly digest on Tuesday 10am user's timezone, preference center | Bad: Daily emails at random times, no way to reduce frequency

#### Imported: SPF (Sender Policy Framework)

TXT record: v=spf1 include:_spf.google.com include:sendgrid.net ~all

#### Imported: 60/40 rule:

- At least 60% text content
- Images for enhancement, not content

#### Imported: Best practices:

- Complement the subject line
- 40-100 characters optimal
- Create curiosity or value
- Different from first line of email

### Not handling partial send failures

Severity: HIGH

Situation: Sending to 10,000 users. API fails at 3,000. No tracking of what sent.
Either double-send or lose 7,000. No way to know who got the email.

Symptoms:
- No per-recipient send logging
- Cannot tell who received email
- Double-sending issues
- No retry mechanism

Why this breaks:
Bulk sends fail partially. APIs timeout. Rate limits hit. Without
tracking individual send status, you cannot recover gracefully.

Recommended fix:

# Track each send individually:

```typescript
async function sendCampaign(emails: string[]) {
  const results = await Promise.allSettled(
    emails.map(async (email) => {
      try {
        const result = await resend.emails.send({ to: email, ... });
        await db.emailLog.create({
          email,
          status: 'sent',
          messageId: result.id,
        });
        return result;
      } catch (error) {
        await db.emailLog.create({
          email,
          status: 'failed',
          error: error.message,
        });
        throw error;
      }
    })
  );

  const failed = results.filter(r => r.status === 'rejected');
  // Retry failed sends or alert
}
```

# Best practices:
- Log every send attempt
- Include message ID for tracking
- Build retry queue for failures
- Monitor success rate per campaign

## Troubleshooting

### Problem: The operator skipped the imported context and answered too generically

**Symptoms:** The result ignores the upstream workflow in `plugins/antigravity-awesome-skills-claude/skills/email-systems`, fails to mention provenance, or does not use any copied source files at all.
**Solution:** Re-open `metadata.json`, `ORIGIN.md`, and the most relevant copied upstream files. Check the `external_source` block first, then restate the provenance before continuing.

### Problem: The imported workflow feels incomplete during review

**Symptoms:** Reviewers can see the generated `SKILL.md`, but they cannot quickly tell which references, examples, or scripts matter for the current task.
**Solution:** Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it.

### Problem: The task drifted into a different specialization

**Symptoms:** The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better.
**Solution:** Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.



## Related Skills

- `@00-andruia-consultant` - Use when the work is better handled by that native specialization after this imported skill establishes context.
- `@00-andruia-consultant-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context.
- `@10-andruia-skill-smith` - Use when the work is better handled by that native specialization after this imported skill establishes context.
- `@10-andruia-skill-smith-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context.

## Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

| Resource family | What it gives the reviewer | Example path |
| --- | --- | --- |
| `references` | copied reference notes, guides, or background material from upstream | `references/n/a` |
| `examples` | worked examples or reusable prompts copied from upstream | `examples/n/a` |
| `scripts` | upstream helper scripts that change execution or validation | `scripts/n/a` |
| `agents` | routing or delegation notes that are genuinely part of the imported package | `agents/n/a` |
| `assets` | supporting assets or schemas copied from the source package | `assets/n/a` |



### Imported Reference Notes

#### Imported: Preference center:

Option to reduce frequency instead of full unsubscribe

### Sending HTML without plain text alternative

Severity: MEDIUM

Situation: Some users see blank emails. Spam filters flagging emails. Accessibility
issues for screen readers. Email clients that strip HTML show nothing.

Symptoms:
- No text/plain part in emails
- Blank emails for some users
- Lower engagement in some segments

Why this breaks:
Not everyone can render HTML. Screen readers work better with plain text.
Spam filters are suspicious of HTML-only. Multipart is the standard.

Recommended fix:

# Always send multipart:
```typescript
await resend.emails.send({
  from: 'you@example.com',
  to: 'user@example.com',
  subject: 'Welcome!',
  html: '<h1>Welcome!</h1><p>Thanks for signing up.</p>',
  text: 'Welcome!\n\nThanks for signing up.',
});
```

# Auto-generate text from HTML:
Use html-to-text library as fallback
But hand-crafted plain text is better

# Plain text should be readable:
Not just HTML stripped of tags
Actual formatted text content

### Sending high volume from new IP immediately

Severity: HIGH

Situation: Just switched providers. Started sending 50,000 emails/day immediately.
Massive deliverability issues. New IP has no reputation. Looks like spam.

Symptoms:
- New IP/provider
- Sending high volume immediately
- Sudden deliverability drop

Why this breaks:
New IPs have no reputation. Sending high volume immediately looks
like a spammer who just spun up. You need to gradually build trust.

Recommended fix:

# IP warm-up schedule:

Week 1: 50-100 emails/day
Week 2: 200-500 emails/day
Week 3: 500-1000 emails/day
Week 4: 1000-5000 emails/day
Continue doubling until at volume

# Best practices:
- Start with most engaged users
- Send to Gmail/Microsoft first (they set reputation)
- Maintain consistent volume
- Don't spike and drop

# During warm-up:
- Monitor deliverability closely
- Check feedback loops
- Adjust pace if issues arise

### Emailing people who did not opt in

Severity: CRITICAL

Situation: Bought an email list. Scraped emails from LinkedIn. Added conference
contacts. Spam complaints through the roof. Provider suspends account.
Maybe a lawsuit.

Symptoms:
- Purchased email lists
- Scraped contacts
- High unsubscribe rate on first send
- Spam complaints above 0.1%

Why this breaks:
Permission-based email is not optional. It is the law (CAN-SPAM, GDPR).
It is also effective - unwilling recipients hurt your metrics and
reputation more than they help.

Recommended fix:

# Permission requirements:

#### Imported: Sharp Edges

### Missing SPF, DKIM, or DMARC records

Severity: CRITICAL

Situation: Sending emails without authentication. Emails going to spam folder.
Low open rates. No idea why. Turns out DNS records were never set up.

Symptoms:
- Emails going to spam
- Low deliverability rates
- mail-tester.com score below 8
- No DMARC reports received

Why this breaks:
Email authentication (SPF, DKIM, DMARC) tells receiving servers you're
legit. Without them, you look like a spammer. Modern email providers
increasingly require all three.

Recommended fix:

# Required DNS records:

#### Imported: DKIM (DomainKeys Identified Mail)

TXT record provided by your email provider
Adds cryptographic signature to emails

#### Imported: DMARC (Domain-based Message Authentication)

TXT record: v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com

# Verify setup:
- Send test email to mail-tester.com
- Check MXToolbox for record validation
- Monitor DMARC reports

### Using shared IP for transactional email

Severity: HIGH

Situation: Password resets going to spam. Using free tier of email provider.
Some other customer on your shared IP got flagged for spam.
Your reputation is ruined by association.

Symptoms:
- Transactional emails in spam
- Inconsistent delivery
- Using same provider for marketing and transactional

Why this breaks:
Shared IPs share reputation. One bad actor affects everyone. For
critical transactional email, you need your own IP or a provider
with strict shared IP policies.

Recommended fix:

# Transactional email strategy:

#### Imported: Option 1: Dedicated IP (high volume)

- Get dedicated IP from your provider
- Warm it up slowly (start with 100/day)
- Maintain consistent volume

#### Imported: Option 2: Transactional-only provider

- Postmark (very strict, great reputation)
- Includes shared pool with high standards

#### Imported: Separate concerns:

- Transactional: Postmark or Resend
- Marketing: ConvertKit or Customer.io
- Never mix marketing and transactional

### Not processing bounce notifications

Severity: HIGH

Situation: Emailing same dead addresses over and over. Bounce rate climbing.
Email provider threatening to suspend account. List is 40% dead.

Symptoms:
- Bounce rate above 2%
- No webhook handlers for bounces
- Same emails failing repeatedly

Why this breaks:
Bounces damage sender reputation. Email providers track bounce rates.
Above 2% and you start looking like a spammer. Dead addresses must
be removed immediately.

Recommended fix:

# Bounce handling requirements:

#### Imported: Hard bounces:

Remove immediately on first occurrence
Invalid address, domain doesn't exist

#### Imported: Soft bounces:

Retry 3 times over 72 hours
After 3 failures, treat as hard bounce

#### Imported: Implementation:

```typescript
// Webhook handler for bounces
app.post('/webhooks/email', (req, res) => {
  const event = req.body;
  if (event.type === 'bounce') {
    await markEmailInvalid(event.email);
    await removeFromAllLists(event.email);
  }
});
```

#### Imported: Monitor:

Track bounce rate by campaign
Alert if bounce rate exceeds 1%

### Missing or hidden unsubscribe link

Severity: CRITICAL

Situation: Users marking as spam because they cannot unsubscribe. Spam complaints
rising. CAN-SPAM violation. Email provider suspends account.

Symptoms:
- Hidden unsubscribe links
- Multi-step unsubscribe process
- No List-Unsubscribe header
- High spam complaint rate

Why this breaks:
Users who cannot unsubscribe will mark as spam. Spam complaints hurt
reputation more than unsubscribes. Also it is literally illegal.
CAN-SPAM, GDPR all require clear unsubscribe.

Recommended fix:

# Unsubscribe requirements:

#### Imported: Visible:

- Above the fold in email footer
- Clear text, not hidden
- Not styled to be invisible

#### Imported: One-click:

- Link directly unsubscribes
- No login required
- No "are you sure" hoops

#### Imported: List-Unsubscribe header:

```
List-Unsubscribe: <mailto:unsubscribe@example.com>,
  <https://example.com/unsubscribe?token=xxx>
List-Unsubscribe-Post: List-Unsubscribe=One-Click
```

#### Imported: Explicit opt-in:

- User actively chooses to receive email
- Not pre-checked boxes
- Clear what they are signing up for

#### Imported: Double opt-in:

- Confirmation email with link
- Only add to list after confirmation
- Best practice for marketing lists

#### Imported: What you cannot do:

- Buy email lists
- Scrape emails from websites
- Add conference contacts without consent
- Use partner/customer lists without consent

#### Imported: Transactional exception:

Password resets, receipts, account alerts
do not need marketing opt-in

### Emails that are mostly or entirely images

Severity: MEDIUM

Situation: Beautiful designed email that is one big image. Users with images
blocked see nothing. Spam filters flag it. Mobile loading is slow.
No one can copy text.

Symptoms:
- Single image emails
- No text content visible
- Missing or generic alt text
- Low engagement when images blocked

Why this breaks:
Images are blocked by default in many clients. Spam filters are
suspicious of image-only emails. Accessibility suffers. Load times
increase.

Recommended fix:

# Balance images and text:

#### Imported: Always include:

- Alt text on every image
- Key message in text, not just image
- Fallback for images-off view

#### Imported: Test:

- Preview with images disabled
- Should still be usable

# Example:
```html
<img
  src="hero.jpg"
  alt="Save 50% this week - use code SAVE50"
  style="max-width: 100%"
/>
<p>Use code <strong>SAVE50</strong> to save 50% this week.</p>
```

### Missing or default preview text

Severity: MEDIUM

Situation: Inbox shows "View this email in browser" or random HTML as preview.
Lower open rates. First impression wasted on boilerplate.

Symptoms:
- View in browser as preview
- HTML code visible in preview
- No preview component in template

Why this breaks:
Preview text is prime real estate - appears right after subject line.
Default or missing preview text wastes this space. Good preview text
increases open rates 10-30%.

Recommended fix:

# Add explicit preview text:

#### Imported: In HTML:

```html
<div style="display:none;max-height:0;overflow:hidden;">
  Your preview text here. This appears in inbox preview.
  <!-- Add whitespace to push footer text out -->
  &nbsp;&zwnj;&nbsp;&zwnj;&nbsp;&zwnj;&nbsp;&zwnj;&nbsp;
</div>
```

#### Imported: With React Email:

```tsx
<Preview>
  Your preview text here. This appears in inbox preview.
</Preview>
```

#### Imported: Validation Checks

### Missing plain text email part

Severity: WARNING

Emails should always include a plain text alternative

Message: Email being sent with HTML but no plain text part. Add 'text:' property for accessibility and deliverability.

### Hardcoded from email address

Severity: WARNING

From addresses should come from environment variables

Message: From email appears hardcoded. Use environment variable for flexibility.

### Missing bounce webhook handler

Severity: WARNING

Email bounces should be handled to maintain list hygiene

Message: Email provider used but no bounce handling detected. Implement webhook handler for bounces.

### Missing List-Unsubscribe header

Severity: INFO

Marketing emails should include List-Unsubscribe header

Message: Marketing email detected without List-Unsubscribe header. Add header for better deliverability.

### Synchronous email send in request handler

Severity: WARNING

Email sends should be queued, not blocking

Message: Email sent synchronously in request handler. Consider queuing for better reliability.

### Email send without retry logic

Severity: INFO

Email sends should have retry mechanism for failures

Message: Email send without apparent retry logic. Add retry for transient failures.

### Email API key in code

Severity: ERROR

API keys should come from environment variables

Message: Email API key appears hardcoded in source code. Use environment variable.

### Bulk email without rate limiting

Severity: WARNING

Bulk sends should respect provider rate limits

Message: Bulk email sending without apparent rate limiting. Add throttling to avoid hitting limits.

### Email without preview text

Severity: INFO

Emails should include preview/preheader text

Message: Email template without preview text. Add hidden preheader for inbox preview.

### Email send without logging

Severity: WARNING

Email sends should be logged for debugging and auditing

Message: Email being sent without apparent logging. Log sends for debugging and compliance.

#### Imported: Collaboration

### Delegation Triggers

- copy|subject|messaging|content -> copywriting (Email needs copy)
- design|template|visual|layout -> ui-design (Email needs design)
- track|analytics|measure|metrics -> analytics-architecture (Email needs tracking)
- infrastructure|deploy|server|queue -> devops (Email needs infrastructure)

### Email Marketing Stack

Skills: email-systems, copywriting, marketing, analytics-architecture

Workflow:

```
1. Infrastructure setup (email-systems)
2. Template creation (email-systems)
3. Copy writing (copywriting)
4. Campaign launch (marketing)
5. Performance tracking (analytics-architecture)
```

### Transactional Email

Skills: email-systems, backend, devops

Workflow:

```
1. Provider setup (email-systems)
2. Template coding (email-systems)
3. Queue integration (backend)
4. Monitoring (devops)
```

#### Imported: Limitations

- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.