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Does CSS !important keyword Work in HTML Email?
An `!important` declaration takes precedence over a normal declaration.
Quick Answer
Does !important keyword work in HTML email?
The CSS !important keyword property is supported in all major email clients tested. You can use it with confidence in your HTML emails.
Which Email Clients Support CSS !important keyword?
CSS support for !important keyword across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ~ Partial | ~ Partial | — |
| Outlook (Windows) | ~ Partial | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✓ Yes | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ~ Partial | ~ Partial | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ~ Partial | ~ Partial | — |
| Fastmail | ✓ Yes | ? | — |
Notes
- #1 Partial. Only supported in lowercase. (See [email-bugs#13](https://github.com/hteumeuleu/email-bugs/issues/13))
- #2 Partial. Only supported inline when using a Non Gmail Account due to the lack of `<style>` support.
- #3 Not supported. The entire declaration is removed if there is no space before `!important`.
- #4 Partial. Only supported with a space before.
- #5 Partial. Not supported inline. (See [email-bugs#31](https://github.com/hteumeuleu/email-bugs/issues/31))
- #6 Partial. Only supported inline due to the lack of `<style>` support.
- #7 Partial. Removed if there is no space before when used with a `background-image` property. (See [email-bugs#16](https://github.com/hteumeuleu/email-bugs/issues/16))
- #8 Partial. Only supported in lowercase.
- #9 Partial. Only supported if not written in lowercase.
Frequently Asked Questions
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