Definition
An email template is a modular HTML framework that defines the structure, layout, and styling for email campaigns. Templates separate the design layer from the content layer, allowing teams to create consistent, on-brand emails without rebuilding the entire structure each time. A well-architected template reduces development time, ensures coding best practices, and provides a consistent experience across different email clients.
Email templates must account for the unique constraints of HTML email development, including limited CSS support, Outlook's rendering engine differences, dark mode variations, and the wide range of screen sizes across desktop and mobile clients. Modern templates are built with responsive design principles and tested thoroughly before deployment.
How It Works
A typical email template consists of a container table for overall width control, a header section with logo and navigation, a content area where campaign-specific content is inserted, and a footer with legal requirements and unsubscribe links. The template uses inline CSS because many email clients strip embedded styles from the head section. Tables are the primary layout mechanism because Outlook uses Microsoft Word's rendering engine, which has poor support for modern CSS layout methods like flexbox and grid.
Template languages like MJML (Mailler ML) abstract away the complexity of table-based layout by providing a simpler markup language that compiles to email-compatible HTML. Handlebars and Liquid are commonly used for adding dynamic content and merge tags within templates. Many ESPs provide drag-and-drop template editors, but custom-coded templates offer more control over design and rendering.
Best Practices
Design mobile-first with a single-column layout as the default and two-column options only where necessary. Keep your template width between 600 and 640 pixels for desktop. Use web-safe fonts or include fallback stacks for custom typefaces. Test every template in the major email clients, including Gmail, Outlook (all versions), Apple Mail, and Yahoo. Implement dark mode support using media queries and conditional CSS. Keep your template code clean and modular by separating the template into reusable partials or includes. Version control your templates and maintain a changelog of updates.
Related Glossary Terms
AMP for Email
AMP for Email is a Google-developed framework that allows email messages to include interactive elements like forms, carousels, accordions, and live content. It turns static emails into dynamic, interactive experiences directly inside the inbox.
Dark Mode
Dark mode in email refers to how email clients render messages when the recipient has dark mode enabled. It affects colour display, image rendering, and readability. Designers use CSS media queries and hybrid coding techniques to control the dark mode appearance.
Dynamic Content
Dynamic content in email refers to content blocks that change based on subscriber data, behavior, or preferences within a single email send.
Email Accessibility
Email accessibility ensures marketing emails are usable by people with disabilities, including those using screen readers, keyboard navigation, or assistive technologies. It follows WCAG 2.1 guidelines for structure, contrast, semantics, and descriptive content.
Email Animation
The use of motion in email through animated GIFs, CSS animations, and video embeds with fallback strategies.
Email CTA
The call-to-action element in an email that drives the primary conversion, designed through button copy, placement, color, and urgency tactics.
Frequently Asked Questions
600 to 640 pixels is the standard maximum width for email templates. This ensures the email displays correctly in most email clients without horizontal scrolling. The content area within that container is typically 560 to 600 pixels.
Outlook on Windows uses Microsoft Word's rendering engine, which has very limited support for CSS layout properties like flexbox, grid, and floats. Tables are the only reliably supported layout method across all email clients, including Outlook.
MJML is an open-source markup language that simplifies email template development. You write cleaner, simpler code and MJML compiles it into full table-based HTML. It is excellent for teams that want to build responsive templates without writing all the complex table code by hand.
Use the CSS media query `@media (prefers-color-scheme: dark)` to apply dark mode-specific styles. Override background colors, text colors, and image sources with darker alternatives. Some email clients also support a `` tag for better automatic color handling.
Standard web CSS frameworks do not work reliably in email due to limited CSS support. There are email-specific frameworks like Foundation for Emails and MJML that provide email-safe components, but they are fundamentally different from their web counterparts.