Your company subscribes to the Office 365 Enterprise E1 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 nee

d 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:

The non-delivery report messages the users are receiving are the result of Backscatter.

Backscatter is the automated bounce messages that are sent by mail servers, typically as a result of incoming spam. Because Excha

nge Online Protection (EOP) is a spam filtering service, email messages sent to nonexistent recipients and to other suspicious destinations are rejected by the service. When this happens, EOP generates a non-delivery report (NDR) message and delivers it ba

ck to the -sender.- Because spammers frequently use a forged or invalid -From- address in their messages, the sender address to which the NDR is sent may result in a backscatter message.

References: http://blogs.technet.com/b/exchange/archive/2014/08/18/s

pam-email-and-office-365-environment-connection-and-content-filtering-in-eop.aspx