You have an Exchange Server 2010 organization that contains five Hub Transport servers, five Mailbox servers and one Edge Transport server. You need to provide a solution to ensure that users can prevent legitimate inbound e-mail messages from being classified as spam.

What should you do?

A.
Enable sender filtering.

B.
Enable Sender ID filtering.

C.
Configure a custom MailTip.

D.
Configure safelist aggregation.