Yesterday I got a question about whether it's possible to import a whitelist, or safe senders list, into FPE. In the FPE docs there are instructions for Creating an allowed senders filter list.
You can import items into the list. See Importing items into a filter list.
Added 2/10/2011: This isn't directly related, but there is a nice video that discusses filtering in general, here, at Filtering in Forefront Protection 2010 for Exchange Server.