Pseudo-element · data last changed 10 Nov 2026
::first-letter in email clients
Works in 10 of 21. Not supported in Gmail, Gmail Android, Gmail iOS and 3 more. Partial in Outlook 365, Outlook (New), Outlook iOS and 1 more. Untested in Superhuman.
Your reader in Outlook Classic sees the email without ::first-letter, 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 ::first-letter in Outlook Classic. Design so the email still reads without it.
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::first-letter 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 Classic | Not supported |
| Outlook Android | Not supported |
| Proton Mail | Not supported |
| Outlook 365 | Partial See caveat 1 |
| Outlook (New) | Partial See caveat 1 |
| Outlook iOS | Partial See caveat 1 |
| Outlook for Mac | Partial See caveat 2 |
| Superhuman | Untested |
Works in 10: Apple Mail, Apple Mail iOS, Yahoo Mail and 7 more. Show all
| Client | Support |
|---|---|
| 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 (2)
- 1. Outlook 365, Outlook (New), Outlook iOS: Partial. Only supported on type selectors.
- 2. Outlook for Mac: Not supported with non Outlook accounts. Partial. Only supported on type selectors.
Caveats as recorded by caniemail (MIT), one entry per wording.
Your next question
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