You are the Exchange administrator for your company. The Exchange organization contains a single Exchange Server 2003 computer.
Users at your company frequently exchange e-mail with another company. A new security agreement between the two companies specifies that all e-mail containing proprietary information must be encrypted when it is transmitted across the Internet. The other company does not have a public key infrastructure.
The other company’s management refuses to use a commercial certification authority (CA) to obtain certificates for its users.
However, they are willing to purchase a small number of certificates for their servers.
You need to ensure that e-mail transmitted across the internet complies with the new security agreement.
What should you do?

A.
Obtain digital certificates for each user in your company. Instruct each user to send digitally signed messages to all users at the other company.

B.
Configure your Exchange server to use Transport Layer Security (TLS) when it connects to the mail server at the other company.
Instruct the e-mail administrator at the other company to configure its mail server in the same way.

C.
Configure your Exchange server to use IPSec to encrypt all outgoing SMTP traffic.

D.
Configure the Exchange HTTP virtual server to require SSL connections.

Explanation:
Incorrect Answers
A. The other company�s management refuses to use a commercial certification authority, therefore we cannto get
certificates of each user.
B. IPSEC can be used, but we need to use certificates or preshared key and encrypt the communication not just the
outgoing email.
D. They do not tell us that they are using OWA to communicate