You have an Exchange Server 2010 organization named contoso.com that contains a mailenabled group named Group1. Users from outside the organization report that e-mail

messages sent to group1@contoso.com generate a non-delivery report (NDR). You need to
ensure that users outside the organization can successfully send e-mail to group1 @
contoso.com. What should you modify?

A.
the authentication settings for the Client Receive connector

B.
the message delivery restrictions for Group1

C.
the moderation settings for Group1

D.
the remote IP address range for the Client Receive connector

Explanation: