CSS Properties

text-decoration-color

CSS property · 15 supported, 3 partial, 2 unsupported across 21 clients

15 of 21 email clients render text-decoration-color fully (Sep 2, 2026 data); it breaks outright in Outlook (New), Outlook Classic.

7/7 webmail, 2/6 desktop, 6/8 mobile clients support text-decoration-color fully.
Unsupported in Outlook (New), Outlook Classic.
Partial in Gmail Android, Gmail iOS, Outlook for Mac, behavior differs from browsers, test before relying on it.
Outlook Classic (Word engine, supported to at least 2029) does not fully support text-decoration-color, and its replacement changes little here; see the deprecation diff.
Across all clients, only 6 of 298 tracked HTML/CSS features render identically everywhere.

Source: caniemail.com (MIT), via the Emailens engine. Last tested upstream Apr 30, 2020, synced by Emailens Sep 2, 2026.

Client Support

Client	Category	Engine	Support
Gmail	webmail	Gmail Web	Supported
Gmail Android	mobile	Gmail Mobile	Partial^{See caveat 1}
Gmail iOS	mobile	Gmail Mobile	Partial^{See caveat 1}
Outlook 365	webmail	Outlook Web	Supported
Outlook (New)	desktop	Outlook Web	Unsupported^{See caveat 2}
Outlook Classic	desktop	Microsoft Word	Unsupported^{See caveat 2}
Outlook iOS	mobile	Outlook Mobile	Supported
Outlook Android	mobile	Outlook Mobile	Supported
Outlook for Mac	desktop	WebKit	Partial^{See caveat 3}
Apple Mail	desktop	WebKit	Supported
Apple Mail iOS	mobile	WebKit	Supported
Yahoo Mail	webmail	Yahoo	Supported
Yahoo Mail Android	mobile	Yahoo	Supported
Yahoo Mail iOS	mobile	Yahoo	Supported
Samsung Mail	mobile	Samsung	Supported
Thunderbird	desktop	Gecko	Supported
HEY Mail	webmail	WebKit	Supported
Proton Mail	webmail	Proton	Supported
AOL Mail	webmail	AOL	Supported
Fastmail	webmail	Fastmail	Supported
Superhuman	desktop	Blink	Unknown

Documented caveats (3)

1.Gmail Android, Gmail iOS: Partial. Not supported with non Google accounts.
2.Outlook (New), Outlook Classic: Not supported, but the proprietary text-underline-color property can be used instead.
3.Outlook for Mac: Supported with prefix -webkit-.

Caveats recorded by caniemail.com (MIT) and carried verbatim, one entry per wording rather than per client.

Client-by-client behaviour for text-decoration-color

Fully supports text-decoration-color (15): Gmail, Outlook 365, Outlook iOS, Outlook Android, Apple Mail, Apple Mail iOS, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, AOL Mail, Fastmail.

Partial support (3): Gmail Android, Gmail iOS, Outlook for Mac. Expect rendering quirks unique to each engine. Partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.

No support (2): Outlook (New), Outlook Classic. Plan fallbacks for these clients before relying on text-decoration-color in production sends.

Behaviour unverified in: Superhuman.