You have Exchange Server 2003 organization. 
The organization contains a front-end server named FE1 and a back-end server named BE1. FE1 is accessible from the Internet by using mail.contoso.com. You plan to transition the organization to Exchange Server 2010. 
You will deploy a Mailbox server named MBX1 and a Client Access server named CAS1. Users will access Outlook Web App （OWA） by using the URL https：//mail.contoso.com. You need to recommend a DNS configuration for the external name of mail.contoso.com. 
Which server should be associated with the name mail.contoso.com？（）

You have an Exchange Server 2003 organization. 
You plan to transition the organization to Exchange Server 2010. 
You need to recommend a plan that allows the Exchange Server 2003 servers to coexist with ExchangeServer 2010 servers. 
The plan must meet the following requirements：
.Support journaling of e-mail messages that are sent to distribution lists from a mailbox on an ExchangeServer 2003 server
.Support journaling of e-mail messages that are sent to distribution lists from a mailbox on an ExchangeServer 2010 server
What should you recommend？（）