Today is widely accepted the importance of the unformal organization and of the roles people play trough the relationships they establish outside of the formal organizational structure. In that sense a deeper knowledge of the unformal organization and the roles played by the collaborators can be a valuable management asset. In this context social network analysis is increansingly being seen as an important methodology to perform such assessment and. The purpose of the present study is to identify patterns in the interactions between people in a corporate environment using a specific and limited opportunity to sample real corporate data and apply Social Network Analysis techniques to a corporate email exchange history. Some interesting patterns emerged confirming the initial assumption of divergence between formal and non-formal structures in corporate contexts.