You are The Exchange administrator for Contoso, Ltd. The network consists of a single Active Directory domain named contoso.com.

The company operates an office in Dallas and an office in Toronto. Both offices are part of a single routing group and a single Exchange organization.

The relevant portion of the network is configured as shown in the exhibit.

DC1 through DC4 are domain controllers. Exch1 through Exch4 are Exchange Server 2003 computers.
The SMTP virtual server on Exch1 is configured as a bridgehead server for an SMTP connecter in the Dallas office.

The SMTP virtual server on Exch3 is configured as a bridgehead server for an SMTP connector in the Toronto office.

The two SMTP connectors are configured with the same cost.
New e-mail policies state that that all outbound and inbound Internet e-mail must be distributed equally between the two Internet connectors.

Outbound Internet e-mail already complies with the new policies. However all inbound Internet e-mail is received through the Internet connection in Dallas.

You need to ensure that inbound internet e-mail also complies with the new policies.

What should you do?

A.
Configure an additional host (A) resource record and mail exchanger (MX) resource record for the contoso.com domain on the Internet DNS servers.
Configure the MX record with the same priority value as that of the existing MX record.

B.
Configure an additional host (A) resource record and mail exchanger (MX) resource record for the contoso.com domain on the Internet DNS servers.
Configure the MX record with a priority value that is higher than that of the existing MX record.

C.
Add the contoso.com namespace to the SMTP connector in Toronto.

D.
Increase the cost of the SMTP connector in Toronto.

Explanation:
To evenly distribute incoming e-mail from outside the organization, a new MX record
must be created, pointed to the Toronto server (Exch3). The MX record must have
the same value as the existing record. If this is not the case, messages will be delivered to
the connector with the lower cost.

Incorrect Answers:
B. Creating a new MX record will enable another path for inbound messages to flow. However, assigning a higher cost will prevent the connection from ever being used unless the original link goes down. Since the messages are not distributed evenly, this can not be the correct answer.
C. Adding the namespace to the SMTP connector in Toronto will forward all outbound mail destined for Toronto to go there without passing through the internet. Since the question states that the incoming mail is already functioning as intended, this step can not be correct.
D. Increasing the cost of the SMTP connector in Toronto will not have any noticeable effect. The connector is designed to handle mail flow between the two sites, and will not affect incoming mail from the internet.