How many email clients support box-shadow?

It works in 14 of 21, partial in 2, not supported in 5.

Does box-shadow work in Apple Mail?

box-shadow works in Apple Mail. Closest to Proton Mail: Apple Mail, which agrees on 203 of the 300 features both are tested on.

box-shadow in Proton Mail

Works box-shadow works in Proton Mail.

Works in 14 of 21 · partial in 2 · not supported in 5

Which clients

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

The fix for the clients that need it

Needed in 7 of 21: Gmail, Outlook Classic, Yahoo Mail Android and 4 more.

Use border as a fallback for box-shadow

instead

5 lines

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

Show the original

before

3 lines

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

A free account opens all 21 clients and keeps your checks for 7 days. Create a free account →

Your next question

Every feature in Proton Mail · box-shadow in every client

Questions

How many email clients support box-shadow?: It works in 14 of 21, partial in 2, not supported in 5.
Does box-shadow work in Apple Mail?: box-shadow works in Apple Mail. Closest to Proton Mail: Apple Mail, which agrees on 203 of the 300 features both are tested on.

To see what in your email Proton Mail does not support, paste the whole email.

Check your email, free

No signup · Five clients free, Outlook Classic included · All 21 with an account

The checker needs a computer screen.

Real captures 14 Oct 2026 on 11 installs · caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 20 Dec 2023 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping