Email CSS, rendering, and compatibility

Movement uses Foundation for Emails (v2) to render all emails. Foundation provides a responsive, table-based grid system with components that are automatically converted into email-client-safe HTML before sending. All CSS is inlined automatically.

Using Foundation markup

You can write Foundation's Inky syntax in three places:

Email Template fields — the markup, header HTML, and footer HTML fields on an Email Template
HTML blocks — the HTML block type in the email builder
Paragraph source mode — the "HTML" tab on paragraph blocks in the email builder

Standard blocks (button, image, heading, etc.) use Foundation automatically — no markup needed.

Common components

Grid

Foundation uses a 12-column responsive grid. Columns stack on mobile (below 596px).

<container>
  <row>
    <columns small="12" large="6">Left on desktop, full width on mobile</columns>
    <columns small="12" large="6">Right on desktop, full width on mobile</columns>
  </row>
</container>

Button

<button href="https://example.com">Click here</button>

Full-width content

<container>
  <row>
    <columns small="12" large="12">
      <p>Full-width paragraph</p>
    </columns>
  </row>
</container>

See the Foundation for Emails docs for the full list of available components.

Email client support

Client	~% of opens	Known issues
Apple Mail (iOS, macOS, iPadOS)	55–60%	None
Gmail (web, Android, iOS)	12–15%	Strips `<style>` tags (inline styles are preserved)
Outlook (New) / Outlook.com	3–5%	None
Outlook Classic (Windows: 2007–2019, M365)	3–5% overall, but 15–30%+ for enterprise/union audiences	Uses Microsoft Word as its rendering engine. No responsive media queries, no rounded corners, no CSS background images, button padding can render inconsistently, no web fonts, no box-shadow/gradients.
Outlook for Mac	1–2%	None (uses WebKit)
Yahoo Mail	3–4%	None
Thunderbird	<1%	None
Samsung Mail	1–2%	None

Percentages are approximate industry figures (Litmus). Actual figures vary significantly by audience.

Outlook Classic note: Microsoft is gradually replacing Outlook Classic with Outlook (New), which uses a modern web rendering engine without these limitations. However, many organisations — particularly in the union and political sectors — remain on Outlook Classic.