About
Email has the highest ROI of any marketing channel. $36 for every
name: email-systems description: 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. risk: none source: vibeship-spawner-skills (Apache 2.0) date_added: 2026-02-27
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.
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
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
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'
