Mobile Use of Email on the Rise - Adapt Your Emails

M:Metrics released a study on U.S. mobile subscriber monthly usage of content and applications. They found an increase of 5% in the mobile activity of viewing personal email. The report also noted an increase of 6.4% in the mobile activity of viewing work emails.

This means not only must your content and links be mobile friendly but your subject lines should be shorter if your audience is apt to mobile use.