Skip to main content

Our email CSS engine is open source. Give it a star on GitHub 

Emailens
Sign in

word-break in Thunderbird

Works word-break works in Thunderbird.

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

The fix for the clients that need it

Needed in 17 of 21: Outlook Classic, Yahoo Mail, Yahoo Mail Android and 14 more.

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

instead 
<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 
<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 →

Your next question

Every feature in Thunderbird · 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.
Does word-break work in Apple Mail?
word-break is partly supported in Apple Mail. Closest to Thunderbird: Apple Mail, which agrees on 219 of the 261 features both are tested on.

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

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