Email has evolved as the most widely used information system in organisations. Many organisations are now dependent on the use of email to manage internal communication as well as other communication and business processes. With this emergence of the universal use of email have emerged some negative aspects of email usage which have a negative impact on personal and organisational productivity. It is now necessary to recognise these negative impacts of email so that structures may be put in place to minimise and control them and related impacts on productivity. In an approach to quantify the negative impact of email this paper identifies negative aspects of email usage and proposes a model which may be used to quantify each aspect and, in turn, quantify the impact of these aspects on productivity. This approach would allow the confirmation of negative issues of email usage and allow formulation of approaches for their management.