I need to migrate a Groupwise 6.5 installation with approx. 100 mailboxes to Exchange (not my decision!). I have obtained (but not yet fully read) the Microsoft document titled Microsoft Exchange Server 2003 Interoperability and Migration Guide.
Obviously, the above document is about migrating to Exchange 2003. My question is: Should I instead consider migrating to 2007 (especially in light of the fact that a subsequent move from 2003 to 2007 is not just an in-place upgrade)? If so, is there a similar document for that? Its not that I have a stron preference for 2007, I just want to know my options.
Any other advice (and maybe recommendations for tools to use) would be much appreciated.