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overflow-wrap in Fastmail

Untested caniemail has no record for overflow-wrap in Fastmail.

Works in 2 of 21 · partial in 3 · not supported in 13 · 3 untested

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

What to do instead in Fastmail

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

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Your next question

Every feature in Fastmail · overflow-wrap in every client

Questions

How many email clients support overflow-wrap?
It works in 2 of 21, partial in 3, not supported in 13, 3 untested.
What do I use instead of overflow-wrap in Fastmail?
Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert &#8203; in a cell that has a width.
Does overflow-wrap work in Apple Mail?
overflow-wrap is partly supported in Apple Mail. Closest to Fastmail: Apple Mail, which agrees on 192 of the 235 features both are tested on.

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

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caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 3 Aug 2022 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping