Which three actions should you perform?

You have an Exchange Server 2013 organization that contains one Client Access server named EX1
and one Mailbox server named EX2.
You have a perimeter network and an internal network. The perimeter network contains an Edge
Transport server named EX3 that has Exchange Server 2010 installed.
You need to ensure that all of the email messages sent to and received from the Internet are routed
through the EX3. Which three actions should you perform? (Each correct answer presents part of the
solution. Choose three.)

A.
Allow SMTP traffic between EX3 and EX2.

B.
Create an Edge Subscription.

C.
Allow traffic over TCP 50636 from EX1 to EX3.

D.
Allow SMTP traffic between EX3 and EX1.

E.
Allow traffic over TCP 50636 from EX2 to EX3.

F.
Modify the default Receive connector on EX2.

Explanation:
To establish Internet mail through an Edge Transport server, subscribe the
Edge Transport server to an Active Directory site. This automatically creates the two Send
connectors required for Internet mail flow: ✑ A Send connector configured to send outbound email
to all Internet domains. ✑ A Send connector configured to send inbound email from the Edge
Transport server to an Exchange 2013 Mailbox server.
SMTP traffic and ports TCP 50636 must be allowed between the mailbox server (routing service) and
the Edge server.