Around half of SFMC client sends we audit have a mobile open rate that matches desktop - roughly 50/50. Yet the email is designed desktop-first, with 10px font, multi-column layouts, and buttons that shrink below finger-size on small screens. The mobile half loses interest before scrolling.
SFMC offers three paths to responsive email. Pick the one that matches the team's technical comfort and design complexity.
Approach 1: Mobile Aware (fastest)
Design the email as a single column with large fonts and big buttons. It looks fine on desktop and naturally works on mobile - no media queries, no CSS tricks.
When to use: simple layouts, tight deadline, non-technical marketers owning the template.
Rule: if someone asks "does this need media queries?" and you don't have a clear yes, Mobile Aware is the answer.
Approach 2: Mobile Responsive (most flexible)
Use @media query CSS to switch layout based on viewport width. Desktop sees 2-3 columns; mobile stacks to 1 column. Fonts scale.
Outlook compatibility catch: Outlook (desktop versions) doesn't support external stylesheets or