Email Rendering Support
Email clients disagree about how HTML and CSS are displayed, so an Edition that looks perfect in one inbox can break in another. This reference summarizes how common content types render across the major clients an Author is likely to target, so you can design Broadcasts that hold up everywhere. Always send a test to real accounts before you Broadcast — (confirm the exact preview and seed-test steps in your account).
Reference
Support levels: Full = renders as designed; Partial = renders with caveats or fallbacks; Limited = often stripped, altered, or ignored.
| Content type | Outlook (desktop, Windows) | Gmail (web + app) | Apple Mail / iOS | Mobile (general) | Dark mode |
|---|---|---|---|---|---|
| Basic HTML + inline styles | Full | Full | Full | Full | Partial |
| Web fonts (custom typefaces) | Limited (falls back to a system font) | Partial | Full | Partial | Full |
| Background images | Limited | Partial | Full | Partial | Full |
Rounded corners / CSS border-radius | Limited (renders square) | Full | Full | Full | Full |
| Animated GIF | Limited (shows first frame) | Full | Full | Full | Full |
| Embedded video | Limited (use a poster image + link) | Limited | Partial | Partial | n/a |
| Interactive content (polls, surveys) | Limited (shows static fallback) | Partial | Partial | Partial | Partial |
| Media queries / responsive layout | Limited | Partial | Full | Full | n/a |
| Dark-mode color inversion | n/a | Partial | Partial | Partial | Partial |
Support varies by client version; treat this as guidance, not a guarantee.
Notes
- Outlook (Windows desktop) uses a legacy rendering engine, so it is usually the hardest target. Favor table-based layouts, inline styles, and a solid background color behind any background image.
- Provide a fallback for every rich element. Interactive content and video should degrade to a static image or a link that opens the full experience in a browser. See Surveys in email.
- Dark mode may recolor text and backgrounds automatically. Test with transparent-background logos and avoid text baked into images, which can become unreadable.
- Mobile first. A large share of subscribers open on phones; keep a single-column layout, tap-friendly buttons, and legible font sizes.
- Personalization tokens render as plain text and are safe across all clients — see Personalization tags.
- When in doubt, keep the design simple and test with a real seed list before every Broadcast.
Related
Canonical terms: Author, Edition, Folder (Project Folder), Broadcast. See the Glossary.