box-shadow

Client-by-client behaviour for box-shadow

Fully supports box-shadow (9): Outlook 365, Outlook iOS, Outlook Android, Apple Mail, Apple Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Superhuman.

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

No support (4): Gmail, Outlook (New), Outlook Classic, Yahoo Mail. Plan fallbacks for these clients before relying on box-shadow in production sends.

Fixes & Workarounds

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.card {
  border: 1px solid #e0e0e0;
  /* box-shadow as progressive enhancement */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

Production guidance for box-shadow

box-shadow is a CSS property. Across the email client matrix, 9 of 15 tracked clients support it fully, 2 only partially, and 4 not at all. The clients most likely to require a workaround for this feature are Gmail, Outlook (New), 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 box-shadow 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.