To make things even more difficult, very few people view an email on only one
device. They switch from their smartphone to their laptop to their tablet and
back to their mobile phone during the course of a day. This means that, although
sending two versions of your email is an option (one for mobile, one for desktops),
it’s probably not the best solution. You want an email that displays well across as
many different clients and operating systems as possible. One way to achieve this
is through responsive email design