The Influence of E-Mail as an Interoffice Communication Tool in Small Organizations
http://baywood.metapress.com/link.asp?target=contribution&id=2NGUGT8XM66PE9WY
  access restricted (by the publisher) to members/subscribers/customers only
  peer-reviewed

Adrian, C. Mitchell
Journal of Technical Writing and Communication
2001

Abstract:

E-mail has significantly impacted the way we communicate in business, possibly going so far as to affect the social structure of organizations. One under-explored effect of e-mail is how it impacts communication in smaller organizations. Given the ability of regular face-to-face interaction, is e-mail necessary to boost communication? A report of employee attitudes in one small business did provide an opportunity to observe the impact of e-mail on communications and employee attitudes. As a result, it is suspected that interoffice e-mail may serve to link formal and informal communication channels, particularly in terms of including managers to the informal communications network.