Email Template - Responsive Transactional Emails Skill

Email Template - Responsive Transactional Emails

Description

Provides responsive transactional email template patterns for NodeJS-Starter-V1 using React Email and Resend. Covers Scientific Luxury dark-theme email design, template composition with shared components, preview tooling, and integration with the project's cron jobs and notification flows using Australian locale formatting.

When to Apply

Positive Triggers

Creating transactional email templates (welcome, password reset, alerts)
Building notification emails for cron job reports or agent alerts
Designing email layouts that match the Scientific Luxury design system
Setting up email delivery infrastructure (Resend, SMTP, SendGrid)
Adding email preview and testing tooling
User mentions: "email", "template", "notification", "transactional", "welcome email"

Negative Triggers

Building in-app toast notifications (use UI component patterns)
Sending Slack or webhook notifications (use webhook-handler patterns)
Generating PDF reports (use pdf-generator patterns)
Handling email as CSV import data (use csv-processor instead)

Core Directives

The Four Rules of Email Templates

Table-based layout: Email clients do not support CSS Grid/Flexbox — use <table> wrappers
Inline styles: Most clients strip <style> blocks — React Email handles this automatically
Dark theme first: Scientific Luxury OLED aesthetic adapted for email (dark background, spectral accents)
Preview before send: Every template must render in the React Email preview before deployment

Recommended Stack

| Tool | Purpose | Install | |------|---------|---------| | @react-email/components | Component library for email templates | pnpm add @react-email/components | | react-email | Dev server for previewing templates | pnpm add -D react-email | | resend | Email delivery API (recommended) | pnpm add resend |

Alternative Providers

| Provider | When to Use | |----------|------------| | Resend | Recommended — React Email native, simple API | | SendGrid | Enterprise — high volume, advanced analytics | | AWS SES | Cost-effective — already on AWS infrastructure | | SMTP | Self-hosted — full control, no vendor lock-in |

File Structure

apps/web/
├── emails/                      # Email templates
│   ├── components/              # Shared email components
│   │   ├── email-header.tsx     # Logo + brand header
│   │   ├── email-footer.tsx     # Unsubscribe + address
│   │   └── email-button.tsx     # CTA button
│   ├── welcome.tsx              # Welcome email
│   ├── password-reset.tsx       # Password reset
│   ├── daily-report.tsx         # Daily agent report
│   └── alert-notification.tsx   # System alert
├── lib/email/
│   ├── send.ts                  # Email sending utility
│   └── config.ts                # Provider configuration

Template Patterns

Base Layout Component

import {
  Body,
  Container,
  Head,
  Html,
  Preview,
  Section,
} from '@react-email/components';

interface EmailLayoutProps {
  preview: string;
  children: React.ReactNode;
}

export function EmailLayout({ preview, children }: EmailLayoutProps) {
  return (
    <Html>
      <Head />
      <Preview>{preview}</Preview>
      <Body style={body}>
        <Container style={container}>
          {children}
        </Container>
      </Body>
    </Html>
  );
}

// Scientific Luxury email styles (inline for compatibility)
const body = {
  backgroundColor: '#050505',
  fontFamily: "'Inter', 'SF Pro Display', Helvetica, Arial, sans-serif",
  margin: '0',
  padding: '0',
};

const container = {
  backgroundColor: '#0a0a0a',
  border: '1px solid rgba(255, 255, 255, 0.06)',
  borderRadius: '2px',  // rounded-sm equivalent
  margin: '40px auto',
  maxWidth: '560px',
  padding: '32px',
};

Shared Components

import { Heading, Hr, Link, Text } from '@react-email/components';

// Header with brand name
export function EmailHeader({ title }: { title: string }) {
  return (
    <>
      <Text style={brandLabel}>NODEJS-STARTER-V1</Text>
      <Heading style={heading}>{title}</Heading>
      <Hr style={divider} />
    </>
  );
}

// CTA Button — spectral cyan accent
export function EmailButton({ href, children }: { href: string; children: string }) {
  return (
    <Link href={href} style={button}>
      {children}
    </Link>
  );
}

// Footer with unsubscribe
export function EmailFooter() {
  return (
    <>
      <Hr style={divider} />
      <Text style={footer}>
        Sent by NodeJS-Starter-V1 — Brisbane, QLD, Australia
      </Text>
    </>
  );
}

const brandLabel = {
  color: 'rgba(255, 255, 255, 0.3)',
  fontSize: '10px',
  fontFamily: "'JetBrains Mono', monospace",
  letterSpacing: '0.3em',
  textTransform: 'uppercase' as const,
  margin: '0 0 8px',
};

const heading = {
  color: 'rgba(255, 255, 255, 0.9)',
  fontSize: '24px',
  fontWeight: '200',
  letterSpacing: '-0.02em',
  margin: '0 0 24px',
};

const divider = {
  borderColor: 'rgba(255, 255, 255, 0.06)',
  borderWidth: '0.5px',
  margin: '24px 0',
};

const button = {
  backgroundColor: '#00F5FF',
  borderRadius: '2px',
  color: '#050505',
  display: 'inline-block',
  fontFamily: "'Inter', Helvetica, sans-serif",
  fontSize: '14px',
  fontWeight: '500',
  padding: '12px 24px',
  textDecoration: 'none',
};

const footer = {
  color: 'rgba(255, 255, 255, 0.3)',
  fontSize: '11px',
  margin: '0',
};

Example: Daily Report Email

import { Text } from '@react-email/components';
import { EmailLayout } from './components/email-layout';
import { EmailHeader, EmailFooter } from './components/email-header';

interface DailyReportProps {
  date: string;          // DD/MM/YYYY
  total: number;
  completed: number;
  failed: number;
  successRate: string;
}

export function DailyReportEmail({
  date, total, completed, failed, successRate,
}: DailyReportProps) {
  return (
    <EmailLayout preview={`Agent Report — ${date}`}>
      <EmailHeader title="Daily Agent Report" />
      <Text style={metric}>
        <span style={metricLabel}>DATE</span>
        <br />
        <span style={metricValue}>{date}</span>
      </Text>
      <Text style={metric}>
        <span style={metricLabel}>TOTAL RUNS</span>
        <br />
        <span style={metricValue}>{total}</span>
      </Text>
      <Text style={metric}>
        <span style={metricLabel}>SUCCESS RATE</span>
        <br />
        <span style={{ ...metricValue, color: '#00FF88' }}>{successRate}</span>
      </Text>
      {failed > 0 && (
        <Text style={metric}>
          <span style={metricLabel}>FAILED</span>
          <br />
          <span style={{ ...metricValue, color: '#FF4444' }}>{failed}</span>
        </Text>
      )}
      <EmailFooter />
    </EmailLayout>
  );
}

const metric = { margin: '0 0 16px' };
const metricLabel = {
  color: 'rgba(255, 255, 255, 0.3)',
  fontSize: '10px',
  fontFamily: "'JetBrains Mono', monospace",
  letterSpacing: '0.2em',
  textTransform: 'uppercase' as const,
};
const metricValue = {
  color: 'rgba(255, 255, 255, 0.9)',
  fontSize: '20px',
  fontFamily: "'JetBrains Mono', monospace",
  fontWeight: '500',
};

Sending Emails

Resend Integration

// apps/web/lib/email/send.ts
import { Resend } from 'resend';

const resend = new Resend(process.env.RESEND_API_KEY);

interface SendEmailOptions {
  to: string | string[];
  subject: string;
  react: React.ReactElement;
}

export async function sendEmail({ to, subject, react }: SendEmailOptions) {
  const { data, error } = await resend.emails.send({
    from: 'NodeJS-Starter-V1 <noreply@yourdomain.com.au>',
    to,
    subject,
    react,
  });

  if (error) {
    throw new Error(`Email send failed: ${error.message}`);
  }

  return data;
}

Cron Job Integration

Wire into the existing daily report cron:

// apps/web/app/api/cron/daily-report/route.ts
import { sendEmail } from '@/lib/email/send';
import { DailyReportEmail } from '@/emails/daily-report';

// After generating the report...
if (process.env.REPORT_EMAIL_RECIPIENTS) {
  const recipients = process.env.REPORT_EMAIL_RECIPIENTS.split(',');
  await sendEmail({
    to: recipients,
    subject: `Agent Report — ${report.date}`,
    react: DailyReportEmail({
      date: new Date(report.date).toLocaleDateString('en-AU'),
      total: report.summary.total,
      completed: report.summary.completed,
      failed: report.summary.failed,
      successRate: report.summary.successRate,
    }),
  });
}

Scientific Luxury Email Palette

Adapted from the project's design tokens for email client compatibility:

| Token | Value | Usage | |-------|-------|-------| | Background | #050505 | Email body | | Container | #0a0a0a | Content area | | Border | rgba(255, 255, 255, 0.06) | Dividers, container | | Text primary | rgba(255, 255, 255, 0.9) | Headings, values | | Text secondary | rgba(255, 255, 255, 0.7) | Body text | | Text muted | rgba(255, 255, 255, 0.3) | Labels, footer | | Cyan accent | #00F5FF | CTA buttons, links | | Emerald | #00FF88 | Success metrics | | Red | #FF4444 | Failure metrics | | Amber | #FFB800 | Warning states |

Email Client Dark Mode Considerations

Some email clients force light mode. Add fallback:

const container = {
  backgroundColor: '#0a0a0a',
  // Outlook forces white — use border as visual anchor
  border: '1px solid #1a1a1a',
};

Preview and Testing

React Email Dev Server

# Add script to package.json
# "email:dev": "email dev --dir apps/web/emails --port 3001"

pnpm email:dev
# Opens http://localhost:3001 with live preview

Programmatic Rendering (For Tests)

import { render } from '@react-email/render';
import { DailyReportEmail } from '@/emails/daily-report';

const html = await render(
  DailyReportEmail({
    date: '23/01/2026',
    total: 42,
    completed: 38,
    failed: 4,
    successRate: '90.5%',
  })
);
// html is a string of rendered HTML — can be used in tests or SMTP

Anti-Patterns

| Anti-Pattern | Why It Fails | Correct Approach | |---|---|---| | CSS Grid/Flexbox in emails | Not supported in Outlook, Gmail | Table-based layout via React Email | | External <style> blocks | Stripped by most clients | Inline styles (React Email default) | | Light theme email from dark app | Inconsistent brand experience | Dark theme email matching Scientific Luxury | | <img> without alt text | Accessibility failure | Always include descriptive alt | | Hardcoded recipient addresses | Breaks across environments | Use REPORT_EMAIL_RECIPIENTS env var | | Sending without preview | Rendering bugs in production | Always preview in React Email dev server |

Checklist for New Email Templates

Design

[ ] Uses Scientific Luxury palette (dark background, spectral accents)
[ ] Table-based layout (no CSS Grid/Flexbox)
[ ] rounded-sm equivalent (2px border-radius) — no large radii
[ ] JetBrains Mono for data values, Inter for editorial text
[ ] Single pixel borders (rgba(255, 255, 255, 0.06))

Implementation

[ ] Extends EmailLayout base component
[ ] Includes <Preview> text for inbox snippet
[ ] Uses EmailHeader and EmailFooter shared components
[ ] All images have alt attributes
[ ] Props typed with TypeScript interface

Delivery

[ ] sendEmail() utility used (not direct Resend/SMTP calls)
[ ] Recipient from environment variable (not hardcoded)
[ ] Error handling with structured logging
[ ] Tested in React Email dev server

Australian Locale

[ ] Dates formatted as DD/MM/YYYY
[ ] Currency as AUD ($X,XXX.XX)
[ ] Footer references Australian location
[ ] Spelling: colour, behaviour, analyse, organise

Response Format

[AGENT_ACTIVATED]: Email Template
[PHASE]: {Design | Implementation | Review}
[STATUS]: {in_progress | complete}

{email template analysis or implementation guidance}

[NEXT_ACTION]: {what to do next}

Integration Points

Scientific Luxury

Email palette derived from apps/web/lib/design-tokens.ts
Dark background, spectral accents, sharp corners, monospace data values
No standard Bootstrap/Tailwind email themes

Cron Scheduler

Daily report email wired into /api/cron/daily-report route
Alert emails triggered by cron health check failures
cron-scheduler patterns for scheduling digest emails

Structured Logging

Log email_sent, email_failed events with recipient count and template name
Include correlation_id for tracing email delivery through the pipeline

Error Taxonomy

Email delivery failures: SYS_EXTERNAL_EMAIL_PROVIDER (503)
Invalid recipient: DATA_VALIDATION_INVALID_EMAIL (422)
Template rendering errors: SYS_RUNTIME_EMAIL_RENDER (500)

Australian Localisation (en-AU)

Date Format: DD/MM/YYYY in email body
Currency: AUD ($) — formatted as $X,XXX.XX
Timezone: AEST/AEDT — timestamps display Australian time
Spelling: colour, behaviour, analyse, organise, centre
Footer: Australian business address (Brisbane, QLD)

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