Selector or pseudo-class · data last changed 10 Nov 2026
:type-selector in email clients
Works in 17 of 21. Not supported in Proton Mail. Partial in Gmail Android and Gmail iOS. Untested in Superhuman.
Your reader in Proton Mail sees the email without :type-selector, even if it looks right where you tested it.
caniemail (MIT) via @emailens/engine 0.18.22
What to do instead in Proton Mail
Treat type selectors in <style> as a baseline that may not apply. Always set critical typography inline on each text-bearing element. Use type selectors for non-critical refinements only.
There is no drop-in fix for :type-selector in Proton Mail. Design so the email still reads without it.
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:type-selector is not among the 24 features we have screenshotted on real installs. The ones we have →
All 21 clients, problems first
| Client | Support |
|---|---|
| Proton Mail | Not supported |
| Gmail Android | Partial See caveat 1 |
| Gmail iOS | Partial See caveat 1 |
| Superhuman | Untested |
Works in 17: Gmail, Outlook 365, Outlook (New) and 14 more. Show all
| Client | Support |
|---|---|
| Gmail | Works |
| Outlook 365 | Works |
| Outlook (New) | Works |
| Outlook Classic | 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 |
Caveats (1)
- 1. Gmail Android, Gmail iOS: Partial. Not supported with non Google accounts.
Caveats as recorded by caniemail (MIT), one entry per wording.
How :type-selector behaves
Type selectors target elements by tag name (e.g., a, p, h1). They have low specificity and are commonly used as resets or base typography. In email, type selectors live in <style> blocks and apply only on clients that preserve them, which excludes most Outlook builds.
- Type selectors have very low specificity and are easily overridden by inline styles or class selectors.
- Outlook strips <style> blocks, so type selectors are inert there.
- Gmail honors type selectors when <style> survives but rewrites class names that interact with them.
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