You are designing an Exchange organization for a company named Contoso, Ltd. All servers in the organization will have Exchange Server 2010 Service Pack 1 (SP1) installed. Users connect to their mailboxes by using either Microsoft Office Outlook 2003, Microsoft Office Outlook 2007, or Microsoft Outlook 2010. You need to recommend a solution that protects confidential e-mail messages against eavesdropping and tampering. The e-mail messages must be protected while they are in transit and once they are stored.
Which of the following solutions is the best recommendation? (More than one answer choice may achieve the goal. Select the BEST answer.)
A.
Deploy Active Directory Rights Management Services (AD RMS), and then create transport rules based on message classifications.
B.
Deploy certificates from a trusted root certification authority (CA) on all transport servers, and then configure Domain Security.
C.
Issue X.509 digital certificates to all users, and then instruct the users to protect their confidential e-mail messages by using S/MIME.
Require RPC encryption for all mailbox databases, and then instruct all Outlook 2003 users to connect by using Outlook Web App (OWA) only.
D.
Deploy Active Directory Rights Management Services (AD RMS), and then instruct users to protect their confidential e-mail messages by using Outlook Protection Rules.