Email Clients

Yahoo Mail

Yahoo Mail rendering behavior and CSS support.

Overview

ID	Category	Engine	Dark mode
`yahoo-mail`	Webmail	Yahoo	Yes

CSS support

Yahoo Mail has moderate CSS support, sitting between Gmail and Apple Mail:

<style> blocks — supported (unlike Gmail)
Flexbox — unsupported
Grid — unsupported
border-radius — supported
box-shadow — partial support
background-image — supported
opacity — supported
position — unsupported
box-sizing — supported

Key behaviors

Yahoo preserves <style> blocks, so class-based styling works
Media queries are supported, enabling responsive designs
Some CSS properties are prefixed or modified during processing

Recommendations

Yahoo Mail is generally well-behaved — focus testing on Gmail and Outlook first
Use <style> blocks for styling (they work here, unlike Gmail)
Avoid flexbox and grid — use tables for complex layouts

Apple Mail

Apple Mail macOS and iOS rendering behavior and CSS support.

Samsung Mail

Samsung Mail rendering behavior and CSS support.

On this page

Overview CSS support Key behaviors Recommendations