You have an Exchange Server 2010 Service Pack 1 (SP1) organization. The network contains two Active Directory sites named Site1 and Site2. Site1 contains an Edge Transport server named Server1. Each site has a direct connection to the Internet. Server1 receives all of the email sent to the Exchange organization from the Internet. You need to recommend a solution that meets the following requirements:

* Prevents an email message from being returned to the sender if Server1 fails.
* Prevents an email message from being returned to the sender if the connection to the Internet in Site1 fails.

What should you include in the recommendation? (Each correct answer presents a complete solution. Choose all that apply.)

A.
Create a mail exchange (MX) record that points to an Exchange Hosted Service. Configure the Exchange Hosted Service to accept email messages for your SMTP domain.

B.
Deploy a new Edge Transport server named Server2 to Site2. Create a mail exchange (MX) record for Server2.

C.
Deploy a new Edge Transport server named Server2 to Site2. Create a failover cluster that contains Server1 and Server2. Create a mail exchange (MX) record for the cluster.

D.
Deploy a new Edge Transport server named Server2 to Site2. Create a Network Load Balancing cluster that contains Server1 and Server2. Create a mail exchange (MX) record for the cluster.