Why is responsive design important for email?

Over 60% of email opens occur on mobile devices. An email designed only for desktop becomes unreadable on phones-tiny text, horizontal scrolling, impossible-to-tap buttons. Recipients don't struggle; they delete and move on.

Responsive design adapts layout to screen size: single columns on mobile, larger tap targets, readable font sizes, images that scale proportionally. The same email provides an appropriate experience whether viewed on a 27-inch monitor or a 5-inch phone.

Mobile-first is the only responsible approach. Design for the smallest screen first, then enhance for larger ones. A desktop experience that degrades poorly to mobile loses most of your audience. A mobile experience that expands to desktop loses nothing. The math is clear: optimize for where your readers actually are, and increasingly, that's their phones.