A new installation of Exchange Server 2007 may fail to mount the initial mailbox database and any other newly created mailbox databases.
In some scenarios Exchange Server 2007 will not warn about active mailboxes when removing mailbox databases.
Microsoft has released the latest update to the Exchange Server 2010 Mailbox Server Role Requirements Calculator on the MS Exchange Team blog.
How to modify the default database and log file paths for new mailbox databases.
How to migrate mailboxes from Exchange Server 2003 to an Exchange Server 2007 Mailbox server using the management console.
How to modify the default Storage Group and Database settings for the Exchange Server 2007 Mailbox Server.