CSS property · 11 real installs 14 Oct 2026 · data last changed 10 Nov 2026
box-shadow in email clients
Works in 14 of 21. Not supported in Gmail, Outlook Classic, Yahoo Mail Android and 2 more. Partial in Gmail Android and Gmail iOS.
Your reader in Outlook Classic sees the email without box-shadow, even if it looks right where you tested it.
caniemail (MIT) via @emailens/engine 0.18.22
What to do instead in Outlook Classic
Use border as a fallback for box-shadow
.card {
border: 1px solid #e0e0e0;
/* box-shadow as progressive enhancement */
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}Show the original
.card {
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}No signup · Five clients free, Outlook Classic included · All 21 with an account
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box-shadow on 11 real installs
One Emailens probe, screenshotted on each install on 14 October 2026, next to our live preview of the same client. Where box-shadow is supported you should see: box with a red shadow.
caniemail: box-shadow is not supported in Outlook Classic.
caniemail: box-shadow works in Outlook 365.
This Outlook.com install drops the <style> in the head, so only inline styles apply.
caniemail: box-shadow works in Apple Mail.
caniemail: box-shadow works in Apple Mail iOS.
caniemail: box-shadow works in Yahoo Mail.
Also captured, not counted as evidence (4)
- Outlook for Microsoft 365 · not mapped to an engine client yet Real screenshot
- Outlook 2019 for Mac (legacy app) · not counted as Outlook for Mac Real screenshot
This is the legacy Outlook for Mac app. The new Outlook for Mac, which the table describes, drops gradients, grid sizing functions, var() and more.
- Gmail (web) · not counted as Gmail Real screenshot
This Gmail install does not apply Gmail's sanitiser, so it shows more than real Gmail does.
- Windows Mail · not mapped to an engine client yet Real screenshot
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 →
All 21 clients, problems first
| Client | Support |
|---|---|
| Gmail | Not supported |
| Outlook Classic | Not supported |
| Yahoo Mail Android | Not supported |
| Yahoo Mail iOS | Not supported |
| AOL Mail | Not supported |
| Gmail Android | Partial See caveat 1 |
| Gmail iOS | Partial See caveat 1 |
Works in 14: Outlook 365, Outlook (New), Outlook iOS and 11 more. Show all
| Client | Support |
|---|---|
| Outlook 365 | Works |
| Outlook (New) | Works |
| Outlook iOS | Works |
| Outlook Android | Works |
| Outlook for Mac | Works |
| Apple Mail | Works |
| Apple Mail iOS | Works |
| Yahoo Mail | Works See caveat 2 |
| Samsung Mail | Works |
| Thunderbird | Works |
| HEY Mail | Works |
| Proton Mail | Works |
| Fastmail | Works |
| Superhuman | Works |
Caveats (2)
- 1. Gmail Android, Gmail iOS: Partial. Only supported with non Google accounts.
- 2. Yahoo Mail: Observed 2026-10-14 (Emailens real-device probe, Yahoo Mail (Chrome)): A box-shadow on a table cell rendered with its offset and colour.
Caveats as recorded by caniemail (MIT), one entry per wording.
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fix
box-shadow in Outlook Classic · Every feature in Outlook Classic · All email CSS features · What real installs show
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