Email Systems

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

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 ( Welcome {userName}! Get Started ); }

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

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

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

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

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

Always include:

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

Test:

• Preview with images disabled
• Should still be usable

Example:

<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:

In 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>

With React Email:

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

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:

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

• @20-andruia-niche-intelligence - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @advogado-criminal - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @advogado-especialista - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @agent-memory-systems - 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.

Imported Reference Notes

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

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:

Hard bounces:

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

Soft bounces:

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

Implementation:

// 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);
  }
});

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:

Visible:

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

One-click:

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

List-Unsubscribe header:

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

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:

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:

Explicit opt-in:

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

Double opt-in:

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

What you cannot do:

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

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: 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.