You have an Exchange organization named contoso.com. All servers in the organisation have Exchange Server 2010 SP1 installed. The organization contains a mail-enabled domain local group name Group1.

Users from outside the organisation report that all e-mail messages sent to group1@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 advanced settings

B.
the mail flow settings

C.
the group scope

D.
the group type

Explanation:
(Exhibit)