How many email clients support word-break?

It works in 4 of 21, partial in 12, not supported in 5.

Does word-break work in Apple Mail iOS?

word-break is partly supported in Apple Mail iOS. Closest to Apple Mail: Apple Mail iOS, which agrees on 284 of the 298 features both are tested on.

word-break in Apple Mail

Partial word-break is partly supported in Apple Mail.

Buggy.

Works in 4 of 21 · partial in 12 · not supported in 5

Which clients

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

Your reader in Apple Mail may not see word-break the way you wrote it, even if it looks right where you tested it.

What to do instead in Apple Mail

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

instead

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Show the original

before

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

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

What Apple Mail does with word-break

The Emailens probe for word-break on a real install counted as Apple Mail, captured 14 Oct 2026. It shows the problem, not the fix. Where word-break is supported it shows: long word wraps inside the box.

The Emailens probe for word-break on a real Apple Mail (macOS) — Apple Mail

The same probe in the Emailens live preview of Apple Mail — Apple Mail

Every account includes one free real-device check in classic Outlook, Outlook for Mac and Apple Mail, after you verify your email and run one preview, while this month's free capacity lasts. How real-device checks work →

caniemail record, tested upstream 15 Feb 2022

Buggy. Supported but a word-wrap:break-word is applied, making it look like break-all.

Your next question

Every feature in Apple Mail · word-break in every client

Questions

How many email clients support word-break?: It works in 4 of 21, partial in 12, not supported in 5.
What do I use instead of word-break in Apple Mail?: Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.
Does word-break work in Apple Mail iOS?: word-break is partly supported in Apple Mail iOS. Closest to Apple Mail: Apple Mail iOS, which agrees on 284 of the 298 features both are tested on.

To see what else in your email Apple 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 10 installs · caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 15 Feb 2022 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping