Email — Email & Notification Systems

When to Activate

• User invokes /godmode:email
• User says "send emails", "email templates"
• User says "notification system", "push notifications"
• User says "bounce handling", "deliverability"
• Application needs email or notification infrastructure

Workflow

Step 1: Requirements Discovery

# Detect existing email infrastructure
grep -r "resend\|sendgrid\|aws-sdk.*ses\|postmark" \
  package.json pyproject.toml go.mod 2>/dev/null

# Find existing templates
find . -path ./node_modules -prune -o \
  -name "*.mjml" -o -name "*.email.tsx" \
  -o -path "*/emails/*" 2>/dev/null | head -20

# Check for queue system
grep -r "bullmq\|bull\|sqs\|celery" \
  package.json pyproject.toml 2>/dev/null

NOTIFICATION REQUIREMENTS:
  Channels: Email | Push | SMS | In-app
  Email types: Auth (critical) | Transactional (high)
    | Product (medium) | Marketing (low)
  Volume: Trans <N>/day, Marketing <N>/month
  Compliance: CAN-SPAM, GDPR, CASL

IF no queue system: add one (never send sync)
IF no provider: recommend based on needs
IF no DNS auth: set up SPF/DKIM/DMARC

Step 2: Email Service Selection

| Feature     | SendGrid | SES    | Postmark | Resend |
|-------------|----------|--------|----------|--------|
| Best for    | Full feat| Volume | Transact | Dev DX |
| Free tier   | 100/day  | 62K/mo | 100/mo   | 3K/mo  |
| Delivery    | Good     | Good   | Excellent| Good   |
| Templates   | Yes      | SES v2 | Yes      | React  |

IF startup/dev-focused: Resend (best DX)
IF high-volume transactional: Postmark
IF full marketing + transactional: SendGrid
IF AWS-native / cost-sensitive: SES

Step 3: Email Template Design

EMAIL DESIGN CHECKLIST:
  Layout: single column, max 600px, large tap targets
  Content: plain text version, alt text on images
  Legal: visible unsubscribe, physical address
  Technical: inline CSS, table layout (Outlook)
  Deliverability: authenticated from-address,
    List-Unsubscribe header, text:image > 60%

THRESHOLDS:
  Max email size: 100KB (incl. HTML + inline CSS)
  Image hosting: CDN only, no base64 in email
  Preheader text: 40-130 characters

Step 4: Notification Architecture

FLOW:
  Event → Notification Service → User Prefs Check
    → Channel Router → Queue → Provider

CHANNEL MATRIX:
  Email verification: Email=YES
  Password reset: Email=YES
  Order confirmed: Email+Push+In-App=YES
  Payment failed: Email+Push+SMS+In-App=YES
  Comment on post: Push+In-App=YES, Email=OPT
  Marketing: Email=OPT only

THRESHOLDS:
  Rate limit: max 5 non-critical per user per hour
  Digest threshold: > 10 pending → batch to digest
  Queue retry: 3 attempts with exponential backoff
  Submission timeout: 30s per send attempt

Step 5: Delivery Tracking & Bounces

LIFECYCLE: QUEUED→SENT→DELIVERED→OPENED→CLICKED
  └→ BOUNCED | DEFERRED | DROPPED | SPAM

KEY METRICS:
  Delivery rate: > 97%
  Open rate (transactional): > 50%
  Bounce rate: < 2%
  Spam complaint rate: < 0.1%
  Unsubscribe rate: < 1%

BOUNCE HANDLING:
  Hard bounce → suppression list, never email again
  Soft bounce → after 3 in 30 days, treat as hard
  Spam complaint → suppress all, alert team

Step 6: DNS Authentication & Streams

DNS RECORDS (required):
  SPF: TXT "v=spf1 include:<provider> ~all"
  DKIM: TXT <selector>._domainkey with public key
  DMARC: TXT _dmarc "v=DMARC1; p=none"
    Progress: none → quarantine → reject (30 days)

STREAM SEPARATION:
  notifications.myapp.com — Transactional (dedicated IP)
  marketing.myapp.com — Marketing (separate IP)

IP WARM-UP SCHEDULE:
  50/day → 100 → 500 → 2K → 10K → 50K → full
  Duration: 30 days minimum
  IF bounce > 5% at any stage: pause and audit
  IF spam complaints > 0.1%: pause immediately

Step 7: Commit

Commit: "email: <description> — <components>"

Key Behaviors

Never ask to continue. Loop autonomously until done.

1. Separate transactional and marketing streams.
2. Authenticate domain fully. SPF+DKIM+DMARC.
3. Always send plain text version.
4. Honor unsubscribe immediately. Synchronously.
5. Suppression list before every send.
6. Queue all email sends. Never synchronous.
7. Monitor deliverability daily.

HARD RULES

1. Never send email synchronously in request handlers.
2. Never mix transactional/marketing on same domain.
3. Never email a hard-bounced address again.
4. Never skip SPF, DKIM, and DMARC.
5. Never send without checking user preferences.

Auto-Detection

1. Provider SDK: resend, @sendgrid/mail, ses, postmark
2. Templates: emails/, src/emails/, *.mjml
3. Queue: bullmq, sqs, celery
4. DNS: check TXT records for SPF/DKIM/DMARC

Output Format

Email: Provider={name}, Templates={N},
  Channels={N}. DNS: {status}.
  Queue: {system}. Verdict: {verdict}.

TSV Logging

step	component	provider	status	details

Keep/Discard Discipline

KEEP if: email lands in inbox AND template renders
  AND SPF/DKIM/DMARC pass
DISCARD if: lands in spam OR template breaks
  OR authentication fails

Stop Conditions

STOP when: All notification types implemented
  AND SPF+DKIM+DMARC passing
  AND suppression list enforced
  AND bounce webhook active
  OR user requests stop

Error Recovery

• API key missing: print env var name, link to docs.
• Template render error: validate with preview API.
• Webhook signature fails: check signing secret.
• Lands in spam: check DNS auth, sender reputation.
• Bounce rate > 5%: pause, audit suppression list.