You have an Exchange organization named contoso.com. All servers in the organization
have Exchange Server 2010 Service Pack 1 (SP1) installed. The organization contains a
mail-enabled Domain Local group named Group1.
Users from outside the organization report that all e-mail messages sent to
groupl@contoso.com generate a non-delivery report (NDR).
You need to ensure that users from outside the organization can successfully send e-mail to
group1@contoso.com.
What should you modify for Group1?

A.
the group type

B.
the mail flow settings

C.
the advanced settings

D.
the group scope

Explanation: