Your company has an Office 365 subscription. You need to add the label “External” to the subject line of each email message received by your organization from an external sender.
What should you do? used to prepend the subject of the message with a text label.

A.
From the Exchange Control Panel, add a MailTip.

B.
From the Forefront Online Protection Administration Center, set the footer for outbound email.

C.
Run the Enable-InboxRule cmdlet.

D.
From the Exchange Control Panel, run the New Rule wizard.

Explanation:

Transport rules can apply messaging policies to email messages flowing through your organization. It can be