I'm not that comfortable with BES yet, but have worked with Exchange for several years.

We're currently in the process of migrating users from an Exchange 03 environment to an Exchange 07 environment. Obviously only one can be truly "live" so it's the 03. The 07 mailboxes are just linked to the old.

Here's the problem; I need BES to work for people both on the old system and on the new one that's linked to the old. Does anyone have any guidance or advice to offer? I can be more specific on the layout if needed.

Thanks in advance

you can have both running at same time, just dont move the users right away even though this KB says to. Do all the rest though.

KB14502-How to migrate the BlackBerry Enterprise Server from Microsoft Exchange Server 2000 or 2003 to Microsoft Exchange Server 2007

almost forgot, what version BES? only 4.1.4 and higher supports 2007