CSS property · data last changed 10 Nov 2026
nesting in email clients
Works in 2 of 21. Not supported in Gmail, Gmail Android, Gmail iOS and 10 more. Partial in Apple Mail, Samsung Mail and Proton Mail. Untested in HEY Mail, Fastmail and Superhuman.
Your reader in Outlook Classic sees the email without nesting, 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 nesting in Outlook Classic. Design so the email still reads without it.
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nesting 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 |
| Yahoo Mail | Not supported See caveat 2 |
| Yahoo Mail Android | Not supported See caveat 2 |
| Yahoo Mail iOS | Not supported See caveat 2 |
| AOL Mail | Not supported See caveat 2 |
| Apple Mail | Partial See caveat 1 |
| Samsung Mail | Partial See caveat 3 |
| Proton Mail | Partial See caveat 4 |
| HEY Mail | Untested |
| Fastmail | Untested |
| Superhuman | Untested |
| Apple Mail iOS | Works |
| Thunderbird | Works |
Caveats (4)
- 1. Apple Mail: Partial.
E { F {}}doesn’t work, butE { & F {}}does. Full support was added in macOS 14.2. - 2. Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail: Not supported. The nested selectors are removed, making the nested properties apply to the parent selector.
- 3. Samsung Mail: Partial. Not supported with Hotmail/Outlook accounts.
- 4. Proton Mail: Partial.
@mediais not fully supported, and& & &syntax not supported
Caveats as recorded by caniemail (MIT), one entry per wording.
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