max-width

Client-by-client behaviour for max-width

Fully supports max-width (13): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook iOS, Outlook Android, Apple Mail, Apple Mail iOS, Yahoo Mail, Samsung Mail, Thunderbird, HEY Mail, Superhuman.

Partial support (2): Outlook (New), Outlook Classic. Expect rendering quirks unique to each engine — partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.

Fixes & Workarounds

<div style="max-width: 600px; margin: 0 auto;">
  Content here
</div>

<!--[if mso]>
<table role="presentation" width="600" cellpadding="0"
  cellspacing="0" border="0" align="center"><tr><td>
<![endif]-->
<div style="max-width: 600px; margin: 0 auto;">
  Content here
</div>
<!--[if mso]>
</td></tr></table>
<![endif]-->

Production guidance for max-width

max-width is a CSS property. Across the email client matrix, 13 of 15 tracked clients support it fully, 2 only partially, and 0 not at all. The clients most likely to require a workaround for this feature are Outlook Classic. Each of them needs a tailored fallback — see the per-client examples above for the specific code fix Emailens recommends.

When in doubt, ship a baseline that renders without max-width and treat it as progressive enhancement on clients where support is verified. Emailens automatically detects cross-client divergence on this feature when you preview an email, so you can see exactly which template paths break before a campaign goes out.