HTML element · data last changed 10 Nov 2026
<style> in email clients
Works in 16 of 21. Partial in Gmail, Gmail Android, Gmail iOS and 2 more.
Your reader in Outlook Classic may not see <style> the way you wrote it, even if it looks right where you tested it.
caniemail (MIT) via @emailens/engine 0.18.22
What to do instead in Outlook Classic
- Buggy.
<style>elements need to be declared before their rules are used.
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<style> is not among the 24 features we have screenshotted on real installs. The ones we have →
All 21 clients, problems first
| Client | Support |
|---|---|
| Gmail | Partial See caveat 1 |
| Gmail Android | Partial See caveat 2 |
| Gmail iOS | Partial See caveat 2 |
| Outlook Classic | Partial See caveat 3 |
| Proton Mail | Partial See caveat 4 |
Works in 16: Outlook 365, Outlook (New), Outlook iOS and 13 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 |
| Yahoo Mail Android | Works |
| Yahoo Mail iOS | Works |
| Samsung Mail | Works |
| Thunderbird | Works |
| HEY Mail | Works |
| AOL Mail | Works |
| Fastmail | Works |
| Superhuman | Works |
Caveats (4)
- 1. Gmail: Partial. Not supported inside the
<body>. The size of the<style>tag is limited to 16 KB - 2. Gmail Android, Gmail iOS: Partial. Not supported inside the
<body>. Partial. Not supported with non Google accounts. - 3. Outlook Classic: Buggy.
<style>elements need to be declared before their rules are used. - 4. Proton Mail: Partial. Not supported inside the
<body>.
Caveats as recorded by caniemail (MIT), one entry per wording.
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