We recently decommissioned our Blackberry server which provided device management for our Canadian users.  In our Exchange 2010 environment we have ActiveSync disabled for users by default, so we needed to enable it for these users so they could continue to use their devices.

The system administrator provided me with a text file of the users and I used the command below to enable ActiveSync for the users.

Get-Content D:\BBusers.txt | Set-CASMailbox -ActiveSyncEnabled $true

Easy, right?