How to replace an old email system with a new

All organizations that use email face changes in their email systems. While some of these are only a change of version that has little effect on the organization, many will replace old email systems with new ones, and this may have severe consequences. A case study is presented where the replacement of two old mainframe-based email systems with Lotus Notes failed. Based on this failure, seven important requirements are defined to reduce problems organizations face when replacing old email systems with new ones. These requirements are supported with results from other research.