CSS Properties

column-count

CSS property · 15 supported, 0 partial, 6 unsupported across 21 clients

column-count splits content into multiple newspaper-style columns. In email, the property is poorly supported , Outlook ignores it entirely, and Gmail strips it through its sanitizer. Email developers traditionally achieve multi-column layouts using nested tables instead, which is more verbose but reliably renders everywhere.

Client Support

Client	Category	Engine	Support
Gmail	webmail	Gmail Web	Supported
Gmail Android	mobile	Gmail Mobile	Supported
Gmail iOS	mobile	Gmail Mobile	Supported
Outlook 365	webmail	Outlook Web	Supported
Outlook (New)	desktop	Outlook Web	Unsupported
Outlook Classic	desktop	Microsoft Word	Unsupported
Outlook iOS	mobile	Outlook Mobile	Supported
Outlook Android	mobile	Outlook Mobile	Supported
Outlook for Mac	desktop	WebKit	Supported
Apple Mail	desktop	WebKit	Supported
Apple Mail iOS	mobile	WebKit	Supported
Yahoo Mail	webmail	Yahoo	Unsupported
Yahoo Mail Android	mobile	Yahoo	Unsupported
Yahoo Mail iOS	mobile	Yahoo	Unsupported
Samsung Mail	mobile	Samsung	Supported
Thunderbird	desktop	Gecko	Supported
HEY Mail	webmail	WebKit	Supported
Proton Mail	webmail	Proton	Supported
AOL Mail	webmail	AOL	Unsupported
Fastmail	webmail	Fastmail	Supported
Superhuman	desktop	Blink	Supported

Client-by-client behaviour for column-count

Fully supports column-count (15): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook iOS, Outlook Android, Outlook for Mac, Apple Mail, Apple Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, Fastmail, Superhuman.

No support (6): Outlook (New), Outlook Classic, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail. Plan fallbacks for these clients before relying on column-count in production sends.

When to use column-count in email

Modern client-only digest layouts where content flows across two columns automatically.
Footer link grids in templates targeting Apple Mail and Superhuman audiences.
Visual experimentation in marketing emails for high-design audiences.

Rendering behaviour and edge cases

Outlook on Windows ignores column-count and renders all content in a single column.
Gmail strips column-count along with most modern layout properties.
Apple Mail supports column-count correctly but applies its own gutter algorithm that may not match designs.

Recommended fallback strategy

Use nested tables with width="50%" and align="left" for multi-column layouts. If you must use column-count, set up a single-column fallback inside a  conditional so Outlook still receives readable copy.