Your company subscribes to the Office 365 Enterprise El plan. You are the Microsoft Exchange Online
administrator.
In the last week, employees have reported that they are receiving non-delivery report messages
from other companies. The employees have not sent messages to recipients within those
companies.
You need to prevent non-delivery report messages from reaching employees.
Which content filter option should you turn on in the Exchange admin center?
A.
NDR backscatter
B.
Conditional Sender ID filtering: hard fail
C.
SPF record: hard fail
D.
Block all bulk email messages
Explanation:
http://blogs.technet.com/b/exchange/archive/2014/08/18/spam-email-and-office-365-
environment-connectionand-content-filtering-in-eop.aspx