Question 1

What is CanIEmail?

Accepted Answer

CanIEmail is an email client CSS support database (similar to CanIUse for browsers) that documents which CSS properties are supported by which email clients and versions. It covers Gmail, Outlook, Apple Mail, Yahoo, Samsung Email, and dozens more. The RenderOps CanIEmail tool lets you look up any property and get a support matrix instantly.

Question 2

Which CSS properties are not supported in Outlook?

Accepted Answer

Outlook 2013-2021 (Word rendering engine) does not support: CSS Flexbox, CSS Grid, CSS Variables, border-radius on images, position:fixed, CSS animations, SVG backgrounds, background-image on td elements, max-width/min-width, and many more. The CanIEmail tool gives you a full compatibility matrix for any property.

Question 3

What is a VML polyfill for email?

Accepted Answer

VML (Vector Markup Language) is a legacy Microsoft format that Outlook Word rendering engine understands. Since Outlook ignores many CSS properties, VML polyfills replicate CSS effects (like rounded buttons, background images, and shapes) using VML code that Outlook renders correctly while other clients see the CSS version.

Question 4

How do I make CSS Grid work in emails?

Accepted Answer

CSS Grid is not supported in Outlook 2013-2021 or older Gmail. The standard fallback is nested HTML tables. Use the RenderOps Retrofit tool to automatically convert your CSS Grid or Flexbox layouts into bulletproof table-based structures that work in all clients.

Can I Email CSS Support Checker