Email design is a "critical" aspect of using the medium to send marketing messages, a new report has concluded.

A new whitepaper titled Email Marketing Design & Rendering: The New Essentials has been published by marketing agency ExactTarget, claiming that the layout of such messages directly effects whether or not the recipient reads the contents.

It stated that email marketing communications must be engaging for consumers in order to be effective.

Commenting on the paper’s conclusions, industry expert Jeff Chandler added: "Without proper planning, rendering and display issues can distract subscribers from the key marketing message in your email."

A recent study conducted by Forrester Research predicted that spending on email marketing in the US will focus on improving the relevancy of such messages over the next few years.

It forecasted spending on the medium will grow to more than $4 billion by the year 2012.

Forrester Research principal analyst Shar VanBoskirk suggested that firms have recognized the importance of targeting their marketing differently depending on the consumer demographic.