Mail Migration Strategy
Topic Last Modified: 2006-09-14
Migration to a new mail platform can be performed in a single phase or in multiple phases. Although not a true "migration" strategy, a third option is long-term coexistence.
Single-Phase Migration excludes the coexistence phase and migrates all of the users at one time. Generally, this type of migration is only implemented at very small organizations and requires significant planning and testing to ensure that the entire organization will move from Lotus Domino to Microsoft® Exchange Server 2003 seamlessly and not overwhelm the help desk.
For more information about how to identify the steps involved in moving all of your users from Lotus Domino to Exchange Server 2003 simultaneously, see Single-Phase Migration Steps.
Multiple-Phase Migration is the more typical migration path. A multiple-phase migration allows time to test, evaluate, and update the migration plan during the migration period. The migration is implemented in phases by migrating groups and physical locations simultaneously while providing adequate support throughout the transition. Multiple-phase migrations require coexistence during which time mail users must be supported on both the Lotus Domino and Exchange Server 2003 platforms.
Long-Term Coexistence is not considered migration because the step of moving all of the users to the new platform is not fully completed.
Use the flowchart shown in Figure 1 as a reference to determine the type of migration appropriate for your environment.
Figure 1 Developing a migration strategy