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Does CSS CSS Nesting Work in HTML Email?
A syntax for nesting selectors, providing the ability to nest one style rule inside another.
Quick Answer
Does CSS Nesting work in HTML email?
The CSS CSS Nesting property is supported in Apple Mail, Thunderbird. It is NOT supported in Gmail, Outlook (Windows), Outlook (Mac / Web), and others. Always include a safe fallback for unsupported clients.
Which Email Clients Support CSS CSS Nesting?
CSS support for CSS Nesting across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✗ No | ✗ No | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✗ No | ✗ No | — |
| Apple Mail | ~ Partial | ✓ Yes | — |
| Yahoo! Mail | ✗ No | ✗ No | — |
| Samsung Email | ? | ~ Partial | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ? | ? | — |
| Fastmail | ? | ? | — |
Notes
- #1 Partial. `E { F {}}` doesn’t work, but `E { & F {}}` does. Full support was added in macOS 14.2.
- #2 Buggy. The syntax is supported, but nested selectors are prefixed by the webmail, which might invalidate the selector.
- #3 Not supported. The nested selectors are removed, making the nested properties apply to the parent selector.
- #4 Partial. Not supported with Hotmail/Outlook accounts.
Frequently Asked Questions
Related CSS Properties
Test Your Email Now
Paste your HTML and see how it renders in clients that don't support CSS Nesting.