How many email clients support text-shadow?

It works in 12 of 21, not supported in 9.

Does text-shadow work in Fastmail?

text-shadow works in Fastmail. Closest to HEY Mail: Fastmail, which agrees on 173 of the 235 features both are tested on.

text-shadow in HEY Mail

Works text-shadow works in HEY Mail.

Works in 12 of 21 · not supported in 9

Which clients

Works: Outlook 365, Outlook Android, Apple Mail, Apple Mail iOS, Yahoo Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, AOL Mail, Fastmail, Superhuman
Not supported: Gmail, Gmail Android, Gmail iOS, Outlook (New), Outlook Classic, Outlook iOS, Outlook for Mac, Yahoo Mail, Yahoo Mail Android

The fix for the clients that need it

Needed in 9 of 21: Gmail, Gmail Android, Gmail iOS and 6 more.

Use font-weight or border-bottom as alternatives to text-shadow

instead

6 lines

.glow {
  /* text-shadow is not supported in Gmail, Outlook, Yahoo.
     Use font-weight or letter-spacing for emphasis instead. */
  font-weight: bold;
  letter-spacing: 0.5px;
}

Show the original

before

3 lines

.glow {
  text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

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Every feature in HEY Mail · text-shadow in every client

Questions

How many email clients support text-shadow?: It works in 12 of 21, not supported in 9.
Does text-shadow work in Fastmail?: text-shadow works in Fastmail. Closest to HEY Mail: Fastmail, which agrees on 173 of the 235 features both are tested on.

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Real captures 14 Oct 2026 on 11 installs · caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 28 Feb 2019 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping