Does CSS text-decoration-thickness Work in HTML Email?
Sets the thickness of text decoration lines such as underlines.
Does text-decoration-thickness work in HTML email?
The CSS text-decoration-thickness property is supported in Outlook (Mac / Web), Apple Mail, ProtonMail, Fastmail. It is NOT supported in Gmail, Outlook (Windows), Yahoo! Mail, and others. Always include a safe fallback for unsupported clients.
Which Email Clients Support CSS text-decoration-thickness?
CSS support for text-decoration-thickness across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✗ No | ✗ No | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✗ No | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✗ No | ✗ No | — |
| Samsung Email | ? | ✗ No | — |
| Thunderbird | ✗ No | ? | — |
| ProtonMail | ✓ Yes | ✓ Yes | — |
| Fastmail | ✓ Yes | ? | — |
Notes
- #1 Supported with prefix `-webkit-`.
- #2 Not supported, but the proprietary `text-underline-style` property can be used instead with the keyword value `thick`.
Frequently Asked Questions
Related CSS Properties
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