What should you recommend to ensure that Server1 does not receive e-mail messages that are sent to e-mail addresses…?

You are the messaging engineer for your company. The company has an Exchange Server 2007 messaging system. The network contains two Exchange Server 2007 servers named Server1 and Server2. Server1 hosts the Mailbox server role, the Hub Transport server role, and the Client Access server role. Server1 is located on the internal network. Server2 hosts the Edge Transport server role. Server2 is located in the perimeter network. Edge synchronization is configured between Server1 and Server2. You need to ensure that Server1 does not receive e-mail messages that are sent to e-mail addresses that do not exist in the organizations address book. What should you recommend?

A.
On Server2, enable sender filtering.

B.
On Server2, enable recipient filtering.

C.
On Server1, install the anti-spam agents and enable sender filtering.

D.
On Server1, install the anti-spam agents and enable recipient filtering.

Explanation:
EMC > Organization Configuration > Edge Transport > Anti-Spam > Recipient Filtering > Blocked Recipients tab > Block messages sent to recipients not listed in the Global Address list

By default, recipient filtering is enabled on the Edge server for inbound messages from the Internet that arent authenticated. These are treated as external messages.

http://technet.microsoft.com/en-us/library/bb125187.aspx

http://technet.microsoft.com/en-us/library/bb123891.aspx