You install ISA Server 2006 on a computer that has three network adapters. One of the network adapters is connected to the Internet, one is connected to the Internal network, and one is connected to a perimeter network. The perimeter network adapter and the internal network adapter are connected to private address networks.
You configure ISA Server by applying the 3-Leg Perimeter network template. You run the 3-Leg Perimeter Network Template wizard. You then make the following changes to the firewall policy:
� Create an access rule to allow all traffic between the Internal network and the Internet. � Create an access rule to allow all traffic between the Internal network and the perimeter network.
� Create an access rule to allow SMTP traffic from an SMTP server on the perimeter network to a Microsoft Exchange Server computer on the Internal network. � Create a server publishing rule to allow SMTP traffic from the External network to the SMTP server on the perimeter network.
Users report that they cannot receive e-mail messages from users outside of the Internal network.
You need to allow users to receive e-mail messages from other users on the Internet. You do not want to create a server publishing rule.
What should you do?

A.
Change the network rule that controls the route relationship between the perimeter network and the Internal network to Route.

B.
Change all network rules that control the route relationships between the Internal network, perimeter network, and External network to Route.

C.
Change the network rule that controls the route relationship between the perimeter network
and the External network to NAT.

D.
Change all network rules that control the route relationships between the Internal network, perimeter network, and External network to NAT.