MJML
MailMode supports MJML uploads and pasted MJML so you can preview rendered email output in light and dark mode.
MJML Upload and Render Support
Paste MJML, upload an .mjml file, or include an MJML file in a ZIP project. MailMode compiles the MJML before previewing and running checks.
Useful MJML Metadata
MailMode detects mj-title for subject/title checks and mj-preview for preheader checks when those tags are present.
Supported Tags
Common MJML email structure such as mjml, mj-head, mj-title, mj-preview, mj-body, mj-section, mj-column, mj-text, mj-image, mj-button, mj-wrapper and related layout tags should work through the available renderer.
Common Rendering Issues
Advanced includes, custom components, .mjmlconfig workflows and build-time plugins may need to be rendered in your own MJML project first. If pasted scripts appear after the closing mjml tag, MailMode ignores that trailing content for validation.
Dark Mode MJML Best Practices
Keep important colours explicit. Add dark mode CSS in mj-style where needed. Avoid white nested cards without dark equivalents. Test CTA buttons, logos and background wrappers in Authored CSS, Partial Invert and Full Invert modes.