Why e-Mail has become a critical component for information governance implementation

We learned that e-mail is a major area of focus for information governance (IG) efforts, and has become the most common business software application and the backbone of business communications today.  In addition, the authors provided details to support their position by providing 2013 survey results from 2,400 corporate e-mail users from a global perspective.  The results indicated that two-thirds of the respondents stated that e-mail was their favorite form of business communication which surpassed not only social media but also telephone and in-person contact.

 With this detail in mind, briefly state why e-Mail has become a critical component for IG implementation? Support with references