Ithy - Unlock Seamless Email Layouts: Crafting Responsive MJML Columns

Creating responsive HTML emails that look great on all devices can be challenging. MJML (Mailjet Markup Language) simplifies this process significantly. This guide will walk you through generating MJML code for a specific layout: a single column that displays at a fixed width of 700px on desktop screens but responsively adjusts to 63% of the screen width on mobile devices.

Conceptual image illustrating email layout design choices

Choosing the right email layout structure is key for readability and engagement.

Essential Insights

MJML Structure: Emails are built using nested components like <mj-section> and <mj-column>, forming the foundation of your layout.
Responsive Control via CSS: Custom responsiveness is achieved using CSS within <mj-style> tags, particularly media queries to target different screen sizes.
Mobile-First Approach: MJML encourages designing for mobile first. Base styles target mobile, and media queries adapt the layout for larger screens (desktops).

Understanding MJML's Responsive Framework

MJML is engineered to streamline responsive email development. It uses a semantic syntax that compiles down to complex, presentation-table-based HTML optimized for email client compatibility. Its core philosophy is "mobile-first," meaning the default rendering is tailored for smaller screens.

Core Layout Components

mj-section

Sections act as rows in your email layout. They are block-level elements that contain columns. You can control background colors, padding, and importantly, the max-width of a section to constrain your content area, especially on wider screens.

mj-column

Columns reside within sections and hold your actual content (text, images, buttons, etc.). By default, if a section contains multiple columns, they appear side-by-side on desktop and stack vertically on mobile. For a single-column layout, it simply occupies the space defined by its parent section and its own width settings.

Implementing Your Custom Single-Column Layout

To achieve the desired 700px desktop width and 63% mobile width for a single column, we'll leverage MJML's structure combined with custom CSS styles defined within the <mj-head>.

Example of a responsive email template adapting to mobile screen size

MJML helps ensure layouts adapt smoothly from desktop to mobile.

The Strategy: CSS Overrides

While MJML components have attributes for basic styling, precise responsive control often requires custom CSS. We will:

Define a base style for the column targeting mobile devices (63% width).
Use a CSS media query to override this style for desktop screens (700px width).
Assign a CSS class to the column to easily target it with our styles.
Ensure the column is centered on mobile when its width is less than 100%.
Set a max-width on the containing section to prevent unwanted stretching on very large displays.

Mobile First: Setting the 63% Width

Following the mobile-first principle, we define the styles for smaller screens directly. We'll use a CSS class (e.g., responsive-column) and set its width to 63%. This ensures that on mobile devices, the column takes up slightly less than two-thirds of the screen width.

Desktop Override: Achieving the 700px Width

A CSS media query is used to detect screen sizes typical of desktop displays. A common breakpoint is min-width: 480px or min-width: 600px. Inside this query, we override the column's width to the desired fixed value of 700px. The !important flag is often necessary in email CSS to ensure these styles take precedence over default MJML or email client styles.

Centering the Column on Mobile

When the column's width is less than 100% (like our 63% on mobile), it won't automatically center within the section. We need to explicitly add margin: 0 auto; to the column's styles for the mobile view to center it horizontally.

The MJML Code

Here is the complete MJML code implementing the single-column layout with the specified responsive widths:

<mjml>
  <mj-head>
    <!-- Define Title and Preview -->
    <mj-title>Responsive Single Column Layout</mj-title>
    <mj-preview>This email demonstrates a responsive column.</mj-preview>

    <!-- Custom Styles for Responsiveness -->
    <mj-style inline="inline">
      /* Base mobile style: 63% width and centered */
      .responsive-column {
        width: 63% !important;
        max-width: 63%; /* Robustness */
        margin: 0 auto !important; /* Centering */
      }

      /* Desktop override: 700px width */
      @media only screen and (min-width: 480px) {
        .responsive-column {
          width: 700px !important;
          max-width: 700px; /* Robustness */
        }
      }
    </mj-style>

    <!-- Optional: Define default attributes for components -->
    <mj-attributes>
      <mj-text padding="10px 25px" font-size="16px" line-height="1.5" color="#333333" />
      <mj-section padding="20px 0" />
    </mj-attributes>

  </mj-head>
  <mj-body background-color="#f0f0f0">

    <!-- Section containing the column -->
    <!-- max-width ensures the section background/padding doesn't exceed 700px -->
    <mj-section max-width="700px" background-color="#ffffff">

      <!-- The single column with the CSS class applied -->
      <mj-column css-class="responsive-column">

        <!-- Your email content goes here -->
        <mj-text>
          <strong>Welcome to our Responsive Email!</strong>
        </mj-text>
        <mj-text>
          This column demonstrates specific width requirements. On desktop screens (typically wider than 480px), this content area will be exactly 700px wide.
        </mj-text>
        <mj-image src="https://via.placeholder.com/600x200?text=Placeholder+Image" alt="Placeholder Image" padding="10px 0" />
        <mj-text>
          On mobile devices, the column adapts to be 63% of the screen width, ensuring readability and a good user experience. It's also centered horizontally.
        </mj-text>
        <mj-button href="#" background-color="#388278" color="#ffffff">
          Learn More
        </mj-button>

      </mj-column>
    </mj-section>

  </mj-body>
</mjml>

Code Breakdown

<mj-head>: Contains metadata and styles.
- <mj-title> & <mj-preview>: Set the email title (browser tab) and preview text (inbox snippet).
- <mj-style inline="inline">: Defines the custom CSS. The inline="inline" attribute helps MJML inline styles where possible for better compatibility, though media queries remain in a style block.
  - .responsive-column {...}: Sets the base mobile style (63% width, centered).
  - @media only screen and (min-width: 480px) {...}: Contains the desktop override, setting the width to 700px for screens wider than 480px.
- <mj-attributes>: (Optional) Sets default styles for components like mj-text and mj-section.
<mj-body>: The main container for the visible email content.
<mj-section max-width="700px">: The row holding the column. max-width="700px" limits the section's width, aligning with the desktop column width.
<mj-column css-class="responsive-column">: The content column. The css-class attribute links it to our custom styles defined in <mj-style>.
Content Elements (<mj-text>, <mj-image>, <mj-button>): Placeholder content within the column. Remember, columns must contain content.

Visualizing Responsiveness Factors

Achieving the desired layout involves balancing several factors. The radar chart below compares using direct MJML attributes versus the recommended approach (CSS class with media queries) across key aspects of responsive email design.

As illustrated, using CSS classes and media queries provides more precise control over both desktop and mobile widths, facilitates easier centering on mobile, and offers better maintainability and flexibility, although direct attributes might seem simpler initially.

Key Concepts Mindmap

This mindmap outlines the core concepts involved in creating this responsive MJML layout.

mindmap root["Responsive MJML Single-Column Layout"] MJML_Core["MJML Core"] Section[" (max-width: 700px)"] Column[" (css-class: responsive-column)"] Content["Content (, , etc.)"] Styling["Styling & Responsiveness"] Head[""] StyleTag[""] CSS_Class[".responsive-column"] Mobile_Style["Mobile: width: 63% !important; margin: 0 auto !important;"] Media_Query["@media (min-width: 480px)"] Desktop_Style["Desktop: width: 700px !important;"] Principles["Design Principles"] Mobile_First["Mobile-First Approach"] Responsiveness["Cross-Device Compatibility"] Output["Final Output"] Compiled_HTML["Responsive HTML Email"] Testing["Email Client Testing (Litmus, Email on Acid)"] Considerations["Important Considerations"] Compatibility["Outlook Limitations"] Centering["Mobile Centering (margin: auto)"]

The mindmap highlights how MJML components, CSS styles within the head (especially media queries), and core principles like mobile-first design interact to produce the final responsive HTML email.

Important Considerations

Email Client Compatibility

While MJML significantly improves compatibility, email clients render HTML and CSS differently.

Outlook Issues

Desktop versions of Outlook (especially older ones) are notorious for poor CSS support, particularly with media queries. While the fixed 700px width might work via MJML's table structure, the mobile-specific styles (like 63% width) might be ignored. Always test!

Mobile & Webmail Clients

Most modern mobile clients (iOS Mail, Gmail App) and webmail clients (Gmail, Yahoo Mail) have good support for media queries, so the responsive behavior should work as intended.

Testing is Crucial

Never assume your email will render perfectly everywhere. Use email testing platforms like Litmus or Email on Acid to preview your MJML-generated HTML across dozens of different email clients and devices before sending.

Content within Columns

Remember that MJML columns are containers. They must contain other MJML components like <mj-text>, <mj-image>, or <mj-button> to render correctly. An empty column might collapse or cause layout issues.

Comparison: Layout Control Methods

There are different ways to approach width control in MJML. Here's a comparison focusing on achieving specific responsive widths:

Method	Mobile Width Setting	Desktop Width Setting	Centering on Mobile	Pros	Cons
CSS Class + Media Query (Recommended)	Via CSS class in `<mj-style>` (e.g., `width: 63% !important;`)	Via media query in `<mj-style>` (e.g., `width: 700px !important;`)	Easy via CSS (`margin: 0 auto !important;`)	Precise control, clear separation of concerns, good maintainability.	Requires understanding CSS and media queries.
MJML Attributes Only	Set on `<mj-column width="63%">`	Cannot set a different fixed px width directly for desktop via attributes alone. MJML's default responsiveness takes over.	Requires wrapper sections/columns or complex structures; not straightforward.	Simple for basic percentage-based layouts.	Limited control over specific fixed widths on desktop vs. percentage on mobile; difficult to achieve the exact requirement.
Manual HTML/CSS Edits (Post-Compilation)	Manually add CSS rules to compiled HTML.	Manually add CSS rules to compiled HTML.	Manually add CSS rules to compiled HTML.	Ultimate flexibility.	Defeats the purpose of using MJML, error-prone, hard to maintain.

The recommended approach using CSS classes within <mj-style> offers the best balance of control, compatibility, and maintainability for achieving specific responsive width requirements like the one requested.

Deep Dive with MJML Tutorials

For a broader understanding of building responsive emails with MJML, including foundational concepts and practical examples, consider watching a comprehensive tutorial. This video covers the fundamentals of MJML, using its tools, and email design principles.

Watching tutorials like this can solidify your understanding of MJML's syntax, components, and how to effectively structure emails for optimal responsiveness across various platforms.

Frequently Asked Questions (FAQ)

Why use !important in the CSS?

Email clients often have their own default styles, and MJML itself generates inline styles and embedded styles. Using !important increases the specificity of your custom styles, making it more likely they will override any conflicting styles from the email client or MJML's compilation process, ensuring your intended widths are applied.

Can I use a different breakpoint than 480px?

Yes, you can adjust the `min-width` value in the media query (e.g., `@media only screen and (min-width: 600px)`). The optimal breakpoint depends on your design and target audience. 480px is a common starting point to differentiate smaller mobile screens from larger ones and tablets/desktops, but testing is key to determine what works best for your specific layout.

What if the 700px width looks too wide in some clients?

While 700px is achievable, standard email widths are often closer to 600px for maximum compatibility and readability, especially considering preview panes in desktop clients. If 700px causes issues or feels too wide after testing, consider reducing it (e.g., to 640px or 600px). The `max-width="700px"` on the `mj-section` helps contain the visual structure.

Do I need the `max-width` declarations in the CSS?

Including `max-width` alongside `width` (e.g., `width: 63% !important; max-width: 63%;`) adds robustness. While `width` should typically suffice, `max-width` can prevent potential issues in certain clients where the element might try to expand beyond the intended percentage or pixel width. It's a good defensive coding practice in email development.