I’ve written an article on doing this in 2010 but seemed to have skipped 2007, so here goes…
The first step in exporting mailboxes is to make sure that the account you’re using to export mailboxes has permissions to do so. In this case, we’ll give the exportadmin account Import and Export options using the New-ManagementRoleAssignment cmdlet in Exchange 2010:
New-ManagementRoleAssignment –Role “Mailbox Import Export” –User exportadmin
Next, you’ll need a system with Outlook 2010 and the Exchange Management Tools installed. From here, you can export mailboxes into PST files. To do so, run the Export-Mailbox cmdlet with the -Identity option to include the account name of a user and the -PSTFolderPath option to include a file location for the pst file. For example, to export user cedge to a folder called N:\exmerges:
Export-Mailbox -Identity cedge -PSTFolderPath N:\exmerges\cedge.pst