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Does CSS mm unit Work in HTML Email?
Support for millimeters unit
Quick Answer
Does mm unit work in HTML email?
The CSS mm unit property is supported in all major email clients tested. You can use it with confidence in your HTML emails.
Which Email Clients Support CSS mm unit?
CSS support for mm unit across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✓ Yes | ✓ Yes | — |
| Outlook (Windows) | ✓ Yes | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✓ Yes | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✓ Yes | ✓ Yes | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ✓ Yes | ✓ Yes | — |
| Fastmail | ✓ Yes | ? | — |
Frequently Asked Questions
Related CSS Properties
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Paste your HTML and see how it renders in clients that don't support mm unit.