【单选题】You have an Exchange Server 2010 organization.A user named User1 connects to his mailbox by using Microsoft Office Outlook.User1 reports that he is unable to send encrypted e-mail messages to an exter...
A.
Instruct User2 to add a delegate
B.
Instruct User2 to send a signed e-mail message to User1.
C.
Instruct User1 to send a signed e-mail message to User2.
D.
Instruct User1 to modify the sensitivity settings of the e-mail message