CSS in Email Signatures

Email clients have limited CSS support compared to web browsers. Here's what works reliably.

Safe CSS Properties

• color, background-color
• font-family, font-size, font-weight, font-style
• text-align, text-decoration
• padding (on table cells)
• border, border-radius (partial support)
• width, height (on images and tables)

CSS to Avoid

• margin (use padding on cells instead)
• display: flex or display: grid
• position (absolute, relative, fixed)
• float
• CSS variables
• Media queries (limited support)

Always Use Inline Styles

Email clients strip <style> blocks. Always apply CSS as inline styles on each element.