You are the Exchange administrator for your company.
The Exchange organization contains three Exchange Server 2003 computers that run Microsoft Windows Server 2003.
Each Exchange server is used by a separate business unit. Each business unit is located in a separate routing group.
The routing groups are connected by routing group connectors. These routing group connectors are used to deliver internal e-mail messages.
Each business unit has it’s own connection to the internet.
The network connections between the business unit servers are at almost 100 percent utilization.
You need to ensure that each business unit uses its own internet connection to deliver internet e-mail messages. Your solution must not effect the delivery of internal e-mail messages.
What should you do?

A.
Configure the SMTP virtual server on each server to forward all mail to the SMTP smart host that belongs to the isp for the server’s business unit.

B.
Configure the SMTP virtual server on each server to use the IP address of an external DNS server, use the DNS server provided by each business unit’s respective ISP.

C.
In each routing group, create an SMTP connector that defines an SMTP address space of * and restrict the connector scope to the routing group.

D.
In each routing group, create an SMTP connector that defines an SMTP address space of the ISP’s domain used by the business unit.
Configure the SMTP connector to allow messages to be relayed to that domain.

Explanation:

In each routing group, configure an SMTP connector and limit its scope to only that group – Prevents other groups from using the link as well as forwarding all requests that are not handled locally through that connector.
(Note that the connectors between departments will probably have preference since "*" is the most generic match,
and the department connectors will match local resources before this connector, so only internet traffic will get routed out.)
Incorrect answers:
A: Configuring the SMTP virtual server to forward to smart host can’t work because ALL SMTP traffic would be routed there, not just the internet traffic as prescribed
B: Configuring the SMTP virtual server to forward tothe ISP’s DNS server can’t work because ALL SMTP traffic would be routed there, not just the internet traffic as prescribed
D: Since the scope is not limited any request made to the internet can use this link, regardless of its origin. Therefore,
if another group’s Internet link was down, all of their routing would go through this ISP,
which is a clear violation of the requirements of the question that state, "Each TestKing.com department maintains a separate connection to the Internet."