David,
The Exchange option is a licensed option. You would need a key to install it on your Media server. The exchange option is not installed as part of the remote agent.
You need to have the Exchange option licensed and register the license with Symantec so you get the license key. Once you have the key you add it as an option on your Media server by choosing in your Media Server console, 'Tools/Install Options and License keys on this Media Server'
Assuming you do not have a key and depending on how long back you installed BEWS 2010 you may still be able to get the MS Exchange Option to work for a few days in Eval mode. I could be wrong but I think you get to evaluate most options for 30 days or so.