How to migrate from third-party mail servers to Exchange Server 2003 and 2007.
For example, a migration from MDaemon Mail Server to Exchange Server.
Basically the options are: Single Step (also called Big Bang Migration) or using Coexistence
The Big Bang Migration:
All users are moved at the same time, usually during the weekend, and on the first day of the new Exchange Server the Help Desk team is swamped by incidents from the new users.
The coexistence scenario:
Both systems are kept up and running, sharing information and a group of users is migrated at a time. In this scenario, the process is more complex and requires some efforts to make sure that both users (migrated and non-migrated) are able to exchange messages and use both mail systems during the transition. In a coexistence scenario, all steps should be done seamlessly from the user point of view.
Detailed step by step guide for two different scenarios:
Moving from a Linux Mail Server and peer-to-peer network to Exchange Server 2007 (Part 1)
Totally 4 parts following below link:
Moving from MDaemon to Exchange Server 2003/2007 (Part 1)
Totally 7 parts following below link: