You are the systems administrator for your company. You install Windows Essential Business Server 2008 on the network and migrate from Exchange Server 2003 to the Messaging Server. You want to remove the Exchange Server 2003 server from the network and ensure that the Simple Mail Transfer Protocol (SMTP) traffic from the Internet is routed to the Messaging Server.

What should you do?

A.
Create an MX record for the Messaging Server on the DNS server.

B.
Create an A record for the Messaging Server on the DNS server.

C.
Create a PTR record for the Messaging Server on the DNS server.

D.
Create an SRV record for the Messaging Server on the DNS server.

Explanation:
You should create an MX record for the Messaging Server on the DNS server. You should decommission your existing Exchange Server after migrating the mailboxes, public folders, and other settings to the new Messaging Server. Before decommissioning the Exchange Server from the network, you must verify that the mail flow is configured properly to route through the Messaging Server. To verify that the SMTP traffic from the Internet is routed to the Messaging Server, you should create an MX record for the Messaging Server on the DNS server. A mail exchange (MX) record defines hosts that are configured to accept mail for a given domain.

You should not create an A record, PTR record, or SRV record for the Messaging Server on the DNS server because an MX record defines hosts that are configured to accept mail for a given domain. An A record, also known as a host record, is used to map machine or resource host names to IP addresses. A PTR record, also known as a pointer record, is used for reverse lookup queries to resolve IP address to names. A SRV, also known as Service Location record, is used to locate Active Directory infrastructure services.