Skip to main content

Our email CSS engine is open source. Give it a star on GitHub 

Emailens

CSS property · data last changed 10 Nov 2026

white-space in email clients

Works in 15 of 21. Not supported in Outlook Classic and Samsung Mail. Partial in Gmail Android, Gmail iOS, Yahoo Mail Android and 1 more.

Your reader in Outlook Classic sees the email without white-space, even if it looks right where you tested it.

caniemail (MIT) via @emailens/engine 0.18.22

What to do instead in Outlook Classic

There is no drop-in fix for white-space in Outlook Classic. Design so the email still reads without it.

The checker needs a computer screen.

A free account opens all 21 clients and keeps your checks for 7 days. Create a free account →

Every account includes one free real-device check in classic Outlook, Outlook for Mac and Apple Mail, after you verify your email and run one preview, while this month's free capacity lasts. How real-device checks work →

white-space is not among the 24 features we have screenshotted on real installs. The ones we have →

All 21 clients, problems first

ClientSupport
Outlook Classic Not supported
Samsung Mail Not supported
Gmail Android Partial See caveat 1
Gmail iOS Partial See caveat 1
Yahoo Mail Android Partial See caveat 2
Yahoo Mail iOS Partial See caveat 2
Works in 15: Gmail, Outlook 365, Outlook (New) and 12 more. Show all
ClientSupport
Gmail Works
Outlook 365 Works
Outlook (New) Works
Outlook iOS Works See caveat 2
Outlook Android Works See caveat 2
Outlook for Mac Works
Apple Mail Works
Apple Mail iOS Works
Yahoo Mail Works
Thunderbird Works
HEY Mail Works
Proton Mail Works
AOL Mail Works
Fastmail Works
Superhuman Works

Caveats (2)

  1. 1. Gmail Android, Gmail iOS: Partial. Not supported with non Google accounts. Partial. pre value is not supported.
  2. 2. Outlook iOS, Outlook Android, Yahoo Mail Android, Yahoo Mail iOS: Partial. pre value is not supported.

Caveats as recorded by caniemail (MIT), one entry per wording.

Your next question

Every feature in Outlook Classic · All email CSS features · What real installs show

Get new email CSS fixes by email.

caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 28 Feb 2019 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping