Marketing through email used to be a relatively straightforward process, but now that ecommerce software has become more popular and consumers check their messages on a slew of devices, the process has grown more complex. The key to a successful retail marketing email campaign is to appeal to all platforms so messages are displayed correctly and coherently whether recipients are reading them on the small screen of a smartphone or at home on their desktop computer.

Recent data indicated that about 48 percent of emails are read on smartphones and tablets, according to Litmus, an analytics firm that focuses on email data. This means that if a marketing email is designed to be read on a computer, mobile users might not be able to see the message properly. This has the potential to significantly reduce the return on investment of the marketing campaign if half of the recipients aren't even able to see the call to action.

Practical Ecommerce pointed out that when crafting marketing emails, retailers can use responsive designs that are coded to adapt to the device on which the email is viewed. It is important to consider the layout of the email, as one with many columns of information may not appear correctly on a mobile device. The size of fonts, images and clickable buttons and links need to be considered as well, as they can change drastically when viewed on a computer versus a smartphone.