CSS at-rule · data last changed 10 Nov 2026
@supports in email clients
Works in 9 of 21. Not supported in Gmail, Gmail Android, Gmail iOS and 9 more.
Your reader in Outlook Classic sees the email without @supports, 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 @supports in Outlook Classic. Design so the email still reads without it.
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@supports is not among the 24 features we have screenshotted on real installs. The ones we have →
All 21 clients, problems first
| Client | Support |
|---|---|
| Gmail | Not supported |
| Gmail Android | Not supported |
| Gmail iOS | Not supported |
| Outlook 365 | Not supported |
| Outlook (New) | Not supported |
| Outlook Classic | Not supported |
| Outlook iOS | Not supported |
| Outlook Android | Not supported |
| Outlook for Mac | Not supported |
| Thunderbird | Not supported |
| Proton Mail | Not supported |
| Fastmail | Not supported See caveat 2 |
Works in 9: Apple Mail, Apple Mail iOS, Yahoo Mail and 6 more. Show all
| Client | Support |
|---|---|
| Apple Mail | Works |
| Apple Mail iOS | Works |
| Yahoo Mail | Works See caveat 1 |
| Yahoo Mail Android | Works See caveat 1 |
| Yahoo Mail iOS | Works See caveat 1 |
| Samsung Mail | Works |
| HEY Mail | Works |
| AOL Mail | Works See caveat 1 |
| Superhuman | Works |
Caveats (2)
- 1. Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail: Properties not supported by the client are replaced by
_filtered_ainside the parenthesis. - 2. Fastmail: Not supported.
@supportsis transformed into@media not all.
Caveats as recorded by caniemail (MIT), one entry per wording.
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