You deploy a new Exchange Server 2010 organization.You send a test message to an external recipient and immediately receive the following nondelivery report （NDR）： Delivery has failed to these recipients or groups： User1@contoso.com （user1@contoso.com）.
The recipient’s e-mail system isn’t accepting messages now.Please try resending this message later or contact the recipient directly.± You verify that you can succesfully send an e-mail message to User1@contoso.com from an external e-mail system.You need to ensure that you can send e-mails to external recipients from within the Exchange organization.
What should you create？（）

You have an Exchange organization.All servers in the organization have Exchange Server 2010 Service Pack 1 （SP1） installed.The organization contains five Hub Transport servers.All of the Hub Transport servers are listed as source servers for a Send connector to the Internet. 
You need to prevent a Hub Transport server named Hubl from sending and receiving e-mail messages from the Internet.The solution must meet the following requirements： 
（1）Ensure that Mailbox servers can deliver e-mail messages to Hub1.
（2）Ensure that all other Hub Transport servers can deliver e-mail messages to the Internet.
What should you do on Hub1？（）