A lot of people are questioning me about Exchange 5.5 to Exchange, How can I do? I always have the same answer it's not possible through exchange 2007 tools:(.
There are 3third partners working on it, but there is not a tool from Exchange Server 2007 to do this work, but there is a logic way to accomplish this kind of migration, the msexchange team has explained to us below.
Migrating mailboxes from Exchange 5.5 to Exchange Server 2007 directly is not supported. Using native tools, administrators will have to perform this kind of migration as a two-step process which includes:
- Migrating from Exchange 5.5 to Exchange 2003
- Migrating from Exchange 2003 to Exchange 2007
Read more at source: http://msexchangeteam.com/archive/2006/11/29/431687.aspx