Before you can install Exchange 2010, make sure that the server has the necessary prerequisites installed. You must ensure that the appropriate software and operating system prerequisites are installed on the server before you begin your Exchange 2010 installation. To install the prerequisites for all server roles, see Exchange 2010 Prerequisites. For more information about system requirements, see Exchange 2010 System Requirements.

In addition, before you begin your Exchange 2010 installation, be aware of the following:

• For e-mail messages to flow correctly, you must install both the Mailbox server role and the Hub Transport server role in the same Active Directory site.
  
• You can install the Mailbox server role, Hub Transport server role, Client Access server role, and Unified Messaging server role on the same computer or on separate computers. The Edge Transport server role must always be installed on dedicated hardware, and it cannot co-exist with other server roles.
  

To perform the following procedure, the account you use must be delegated membership in the Schema Administrators group if you haven't previously prepared the Active Directory schema.

If you're installing the first Exchange 2010 server in the organization, the account you use must have membership in the Enterprise Administrators group.

If you've already prepared the schema and are not installing the first Exchange 2010 server in the organization, the account you use must be delegated the Organization Management role.

Note:
For information about preparing active directory for Exchange 2010, see Prepare Active Directory and Domains. For information about permissions in Exchange 2010, see Understanding Role Based Access Control.

Installation Type page

1. On the Server Role Selection page, select the server roles that you want to install on the computer and click Next.
   

   Note:
   The Edge Transport server role can't coexist on the same computer with any other server role. You must deploy the Edge Transport server role in a perimeter network and outside your internal Active Directory forest.

2. If you selected Mailbox Role, Client Access Role, Hub Transport Role, and/or Unified Messaging Role, and if this is the first Exchange 2010 server in your organization, on the Exchange Organization page, type a name for your Exchange 2010 organization. The Exchange organization name can contain only the following characters:
   
   • A through Z
     
   • a through z
     
   • 0 through 9
     
   • Space (not leading or trailing)
     
   • Hyphen or dash
     

   Note:
   The organization name can't contain more than 64 characters. The organization name can't be blank. If the organization name contains spaces, you must enclose it in quotation marks.

3. If this is the first Exchange 2010 server in your organization, on the Client Settings page, click the appropriate option based on the client computers.
   

   Note:

   If you have client computers that are running Outlook 2003 or Microsoft Entourage, select Yes, and Exchange 2010 will create a public folder database on the Mailbox server. If all your client computers are running Outlook 2007 or later, public folders are optional in Exchange 2010. If you select No, Exchange 2010 will not create a public folder database on the Mailbox server. You can add a public folder database later, if needed.

4. If you are installing the Client Access server role, Setup will ask if the Client Access role will be Internet-facing. If the Client Access role being installed is intended as an Internet-facing server, enter the domain name you will use for external client access on the Configure Client Access server external domain page, Check the box that says The Client Access server role will be Internet-facing, and enter the URL your clients will use (for example, mail.contoso.com).
   
5. On the Customer Experience Improvement Program page, choose the appropriate selection for your organization, and then click Next.
   
6. On the Readiness Checks page, view the status to determine if the organization and server role prerequisite checks completed successfully. If they have not completed successfully, you must resolve any reported errors before you can install Exchange 2010. You do not need to exit Setup when resolving some of the prerequisite errors. After resolving a reported error, click Retry to re-run the prerequisite check. Be sure to also review any warnings that are reported. If all readiness checks have completed successfully, click Install to install Exchange 2010.
   
7. On the Completion page, click Finish.
   

After you have completed the custom installation, be aware of the following important points:

• After you install the first Exchange 2010 server in an organization, if you create a new recipient object (such as a mailbox, contact, distribution list, mailbox agent, or mail-enabled public folder), it will have a LegacyExchangeDN that corresponds to the new administrative group for the Exchange 2010 server. Because of this LegacyExchangeDN, Outlook will request a full offline address book (OAB) download from the Exchange 2010 server for each user in this organization that logs on to a mailbox using Outlook and using OAB versions 2 or 3. This could cause many simultaneous OAB download requests, which causes high network utilization.
  
• After installing the Unified Messaging server role, you must restart the system to allow the Microsoft Exchange Unified Messaging service to reserve the required TCP ports.