Building an Email Design System
Why Email Needs a Design System
Most companies send dozens of different email types: marketing campaigns, transactional notifications, lifecycle sequences, product updates. Without a design system, each email is built from scratch, leading to inconsistent branding, duplicated effort, and quality variation.
An email design system provides:
- Consistency — every email looks and feels like it comes from the same brand
- Speed — new emails are assembled from existing components, not built from scratch
- Quality — components are tested once across email clients, then reused confidently
- Scalability — non-designers can build on-brand emails using the system
Design Tokens
Design tokens are the foundational values of your email design system. Define these first:
- Colors — primary, secondary, background, text, link, success, warning, error
- Typography — font families (with email-safe fallbacks), sizes, weights, line heights
- Spacing — consistent padding and margin values (8px, 16px, 24px, 32px, 48px)
- Border radius — button radius, card radius, image radius
- Shadows — limited use in email, but define if your brand uses them
Store tokens in a central configuration file. If you use React Email, these map directly to style objects. For traditional email development, create a reference document that designers and developers follow.
Component Library
Core email components to build and test once:
- Header — logo, navigation links (limited), preheader text
- Hero — headline, subtext, primary CTA button, optional image
- Content block — heading, body text, optional image (left/right/full)
- Button — primary, secondary, outline variants with bulletproof rendering
- Card — bordered content container for product features, article previews
- Footer — social links, unsubscribe, physical address, legal text
- Divider — horizontal rule with consistent spacing
- Social icons — SVG or image-based social media icons
Each component should be tested in at least the top 10 email clients before being added to the library. Document known quirks and client-specific overrides.
Template Architecture
Build templates as compositions of components:
- Marketing announcement — Header + Hero + Content Block + CTA + Footer
- Newsletter — Header + multiple Content Blocks + Footer
- Transactional — Header + Content Block (minimal) + Footer (minimal)
- Product update — Header + Feature Cards + CTA + Footer
Using a component-based tool like React Email makes template composition natural — each template is a React component that imports and arranges shared building blocks.
Governance and Maintenance
A design system is only as good as its maintenance:
- Version your components — use semantic versioning so teams can update at their own pace
- Document everything — usage guidelines, do/don't examples, client compatibility notes
- Test regularly — email clients update their rendering engines. Re-test components quarterly.
- Centralize ownership — assign a team or individual responsible for the system
- Gather feedback — regular check-ins with email builders to understand pain points
Start small — build the 5 most-used components first, then expand based on need. A small, well-maintained system beats a comprehensive one that nobody trusts.