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overflow in HEY Mail

Works overflow works in HEY Mail.

Works in 4 of 21 · partial in 16 · not supported in 1

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

The fix for the clients that need it

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

Content will always be visible; design for full content display

instead 
<!-- Show full content, or truncate server-side -->
<div style="max-height: 200px;">
  Shortened content that fits...
  <a href="https://example.com/full">Read more</a>
</div>
Show the original
before 
<div style="max-height: 200px; overflow: hidden;">
  Long content that gets clipped...
</div>

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Your next question

Every feature in HEY Mail · overflow in every client

Questions

How many email clients support overflow?
It works in 4 of 21, partial in 16, not supported in Outlook Classic.
Does overflow work in Fastmail?
overflow works in Fastmail. Closest to HEY Mail: Fastmail, which agrees on 173 of the 235 features both are tested on.

To see what in your email HEY Mail 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 27 May 2025 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping