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Does CSS outline-offset Work in HTML Email?
Controls the position of an outline.
Quick Answer
Does outline-offset work in HTML email?
The CSS outline-offset property is supported in Apple Mail, Samsung Email, Thunderbird, ProtonMail, and others. 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 outline-offset?
CSS support for outline-offset across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✗ No | ✗ No | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✗ No | ✗ No | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✗ No | ✗ No | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ✓ Yes | ✓ Yes | — |
| Fastmail | ✓ Yes | ? | — |
Frequently Asked Questions
Test Your Email Now
Paste your HTML and see how it renders in clients that don't support outline-offset.