You have two Exchange Server 2010 named Server1 and Server2.Server1 has the Mailbox server role installed.Server2 has the Hule Transport and client access server roles installed.You need to ensure that users can send e-mail and receive e-mail by using Windows Live Mail or Microsoft Outlook Express. What should you do？（）

• A、From the command Prompt on server1，run net start MsExchangePOP3
• B、From the command Prompt on Server2，run net start MsExchangePOP3
• C、On Server1 and Server2，modify the properties of the MsExchangePOP3（TCP-in） Windows Firewall rule
• D、On Server1，modify the properties of the MsExchangeIMAP4（TCP-in） Windows Firewall rule.On server2， modify the properties of the client receive connector