I wanted to bring to your attention a typo in the Blackberry Quick Start Guide for Blackberry Enterprise Server. This guide says to set permissions on the Exchange 2007 server you should issue a set-mailboxserver | add-adpermission -user -accessrights GenericRead, GenericWrite -extendedrights Send-As, Receive-As, ms-Exch-Store-Admin. The first command should actually be get-mailboxserver.

This Blackberry document has the correct command.