You have an Exchange 2010 Edge Transport server named Server1. You discover that you
cannot receive e-mail from an organization that uses the contoso.com domain name. You
examine the server logs and discover that the contoso.com servers are configured as open
SMTP relays. You need to ensure that the Edge Transport server can receive e-mail from
contoso.com. What should you do?

A.
Create an IP Allow List entry.

B.
Create an address rewrite entry.

C.
Configure the properties of the Sender ID feature.

D.
Configure the properties of the sender filtering feature.