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 Outlook (New)?

word-break is partly supported in Outlook (New). Closest to Outlook for Mac: Outlook (New), which agrees on 279 of the 299 features both are tested on.

word-break in Outlook for Mac

Partial word-break is partly supported in Outlook for Mac.

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 Outlook for Mac may not see word-break the way you wrote it, even if it looks right where you tested it.

What to do instead in Outlook for Mac

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>

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What Outlook for Mac does with word-break

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 Outlook for Mac · 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 Outlook for Mac?: 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 Outlook (New)?: word-break is partly supported in Outlook (New). Closest to Outlook for Mac: Outlook (New), which agrees on 279 of the 299 features both are tested on.

To see what else in your email Outlook for Mac does not support, paste the whole email.

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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