Schema master (By default, the schema master runs on the first Windows Server 2003 domain controller installed in a forest.)

Microsoft Windows Server 2003 Service Pack 1 (SP1) or a later version, or Windows Server 2003 Windows Server 2003 R2

Global catalog server

In every Active Directory directory service site where you plan to install Exchange 2007, you must have at least one global catalog server that is running Windows Server 2003 SP1 or a later version. This is for the following reasons:

• Windows Server 2003 SP1 supports Exchange 2007 service notifications. When a configuration change occurs in Active Directory, a notification is sent to the service. Several Exchange 2007 services use this notification. The notification mechanism in Windows Server 2003 SP1 is an improvement over the notification mechanism in Microsoft Windows 2000 Server.
  
• Windows Server 2003 SP1 and later versions allow users to browse the address book in Microsoft Outlook Web Access.
  
• Windows Server 2003 SP1 and later versions provide the ability to look up distribution list membership in a more efficient manner than in Windows 2000 Server.
  

Domain controllers

The following applies to domain controllers:

• For the release to manufacturing (RTM) version of Exchange 2007, in each domain (including child domains) where you have the Exchange Enterprise Servers and Exchange Domain Servers groups and therefore must run Setup /PrepareLegacyExchangePermissions, you must have at least one domain controller that is running Windows Server 2003 SP1 or a later version.
  
• For Exchange 2007 RTM and Exchange 2007 SP1, in each domain (including child domains) where you plan to install Exchange 2007, you must have at least one domain controller that is running at least Windows Server 2003 SP1.
  
• In each Active Directory site where you plan to install Exchange 2007, you must have at least one domain controller that is also a global catalog server and is running Windows Server 2003 SP1 or a later version.
  
• If you have any domain controllers that are running Windows 2000 Server, when you prepare Active Directory and domains for Exchange 2007 RTM and when you install Exchange 2007 RTM, you must run Setup.com from a Command Prompt window, and you must use the /DomainController parameter to specify a domain controller that is running Windows Server 2003 SP1or a later version. When you prepare Active Directory and domains for Exchange 2007 SP1 and when you install Exchange 2007 SP1, you do not have to specify a domain controller that is running Windows Server 2003 SP1 or a later version.
  
• Although you cannot install Exchange 2007 RTM on a server running Windows Server 2008, Exchange 2007 RTM is supported for use with Windows Server 2008 directory servers. Similarly, Exchange Server 2003 Service Pack 2 (SP2) cannot be installed on computers running Windows Server 2008, but it is supported for use with Windows Server 2008 directory servers.
  
• Exchange 2000 Server Service Pack 3 (SP3) cannot be installed on computers running Windows Server 2008, nor is it supported for use with Windows Server 2008 directory servers. An Exchange 2000 SP3 server can exist in an Active Directory forest that contains Windows Server 2008 directory servers, but Windows Server 2008 directory servers should not be installed in Active Directory sites that contain Exchange 2000 servers.
  
• For more information about the relationship between Microsoft Exchange and Windows Server 2008 directory servers, see Exchange Server 2007: Platforms, Editions, and Versions.
  

Domain controllers that are not English

If you plan to use Outlook Web Access in your organization, you must install the hotfix that is described in Microsoft Knowledge Base article 919166, The address book function in Exchange 2007 is broken when an Exchange OWA client and a Windows Server 2003-based domain controller do not have the same locale setting.

Read-only domain controllers

No version of Microsoft Exchange uses read-only domain controllers or read-only global catalog servers. However, Microsoft Exchange works in environments that include read-only domain controllers or read-only global catalog servers, as long as writeable domain controllers are available. In these environments, Exchange 2007 effectively ignores read-only domain controllers and read-only global catalog servers.

Domain functional level

You should use at least Windows 2000 Server native for all domains in the Active Directory forest where you will install Exchange 2007 or that will host Exchange 2007 recipients.

For more information about domain and forest functional levels, see Functional Levels Background Information in the Windows Server 2003 Deployment Guide.

Forest functional level

If you plan to use any of the following advanced features, the forest functional level must be Windows Server 2003 in each forest that contains Exchange servers:

• Forest-to-forest delegation. For more information, see How to Configure Cross-Forest Administration.
  
• Ability for a user to select the type of free/busy information that will be available to users in another forest.
  

  Note:
  You can configure your Exchange servers to share free/busy information across forests that do not have a trust relationship. However, if you do this, users will not be able to select the type of free/busy information that will be available to users in another forest. The types of free/busy information are None; Free/Busy time; Free/Busy time, subject, location; and Full Details.

If you do not want to use any of these advanced features, the forest functional level must be at least Windows 2000 Server.

Multiple forest deployments

All multiple forest topologies containing Exchange 2007 require directory servers in each forest running Windows Server 2003 with Service Pack 1 or later.

Trust between forests

If your topology includes multiple Active Directory forests in which Exchange is installed, and if you want to use any of the following advanced features, you must establish a trust relationship between the forests that have Exchange installed:

• Forest-to-forest delegation. For more information, see How to Configure Cross-Forest Administration.
  
• Ability for a user to select the type of free/busy information that will be available to users in another forest.
  

  Note:
  You can configure your Exchange servers to share free/busy information across forests that do not have a trust relationship. However, if you do this, users will not be able to select the type of free/busy information that will be available to users in another forest. The types of free/busy information are None; Free/Busy time; Free/Busy time, subject, location; and Full Details.

If you have a resource forest topology, you must have either an external domain trust relationship from the Exchange forest to your account domains in other forests or a forest trust relationship from the Exchange forest to the accounts forest.

Servers running Microsoft Exchange Server version 5.5

You cannot have any Exchange Server 5.5 servers in your Exchange organization, and your Exchange organization must be running in native mode. For more information about how to convert an Exchange organization to native mode, see How to Convert from Mixed Mode to Native Mode in Exchange.

Disjoint namespace

A disjoint namespace is the scenario in which the primary Domain Name System (DNS) suffix of a computer does not match the suffix of the domain name where that computer resides. Limited tests were performed to validate Exchange 2007 on a computer that has a disjoint DNS namespace. These tests showed that any issues resulting from this configuration may be resolved by ensuring that the DNS suffix search list on an Exchange server references all DNS namespaces that are deployed within the organization. The list of namespaces should include not only Active Directory and Exchange servers, but also the namespaces for other servers with which Exchange may interoperate, such as monitoring servers or servers for third-party applications. For detailed information about supported scenarios with disjoint namespaces, see Understanding Disjoint Namespace Scenarios with Exchange 2007.

If you are having difficulty resolving issues with a disjoint namespace that is not one of the supported disjoint namespace topologies, contact Microsoft Services.

DNS

You must configure DNS correctly in your Active Directory forest.

Single-label DNS names

Single-label DNS names are not recommended for use with Exchange 2007 or Exchange 2007 SP1. For additional information about single-label DNS names, see Knowledge Base article 300684, Information about configuring Windows for domains with single-label DNS names.

Active Directory domain names

Previous versions of Microsoft Exchange supported the renaming of Active Directory domains that contained Exchange servers. Exchange 2007 does not support renaming domains that contain computers running Exchange 2007. If you rename a domain that contains computers that are running Exchange 2007, several services, including the Microsoft Exchange System Attendant service will not start, and the Exchange servers will no longer function correctly. For more information about renaming domains containing Exchange 2007, see Knowledge Base article 925822, The Microsoft Exchange System Attendant service does not start on a computer that is running Exchange Server 2007 after you rename a Windows Server 2003 domain.

Active Directory preparation

You must prepare Active Directory and your domain for the Exchange 2007 installation. For detailed steps, see How to Prepare Active Directory and Domains.

Processor

• x64 architecture-based computer with Intel processor that supports Intel 64 architecture (formerly known as Intel EM64T)
  
• AMD processor that supports the AMD64 platform
  
• Intel Itanium IA64 processors not supported
  
• Intel Pentium or compatible 800-megahertz (MHz) or faster 32-bit processor (for testing and training purposes only; not supported in production)
  

• It is supported to install the Exchange management tools on a computer that has a 32-bit processor.
  

  Note:
  It is not supported to install Exchange 2007 server roles on a computer that has a 32-bit processor in a production environment. You can install Exchange 2007 server roles on a computer that has a 32-bit processor in testing and training environments only.

• It is supported to install the management tools on a computer that has a 32-bit processor; however, you must download the 32-bit version of Exchange 2007. For download information, see Microsoft Exchange Server 2007 Management Tools (32-Bit).
  
• It is also supported to install the Exchange management tools on a computer that has a 64-bit processor.
  

  Note:
  For information about how to install the management tools, see How to Install the Exchange 2007 Management Tools.

• It is supported to use Setup.com to prepare Active Directory and domains for Exchange 2007 from a computer that has a 32-bit processor. For more information, see How to Prepare Active Directory and Domains.
  

Memory

• Minimum: 2 gigabytes (GB) of RAM
  
• Recommended: 2 GB of RAM per server plus 5 megabytes (MB) of RAM per mailbox
  
• Minimum based on number of storage groups, see Planning Memory Configurations.
  

This recommended memory configuration is suggested as a way to optimize performance for Exchange 2007. Specifically, it allows Exchange to use an appropriately sized database cache, which reduces database disk input/output (I/O). These recommendations are oriented toward authorized production environments that have many users with large, frequently used mailboxes.

Paging file size

Equal to the amount of RAM in the server plus 10 MB

This paging file size recommendation accounts for the amount of memory needed to collect information if the operating system fails. By default, if the operating system fails, it will copy everything in memory to a .dmp file. That file can be examined later to determine the cause of the failure. To be able to copy everything that is stored in memory, you must have a paging file size that can hold everything in memory, plus some additional space to gather the data.

Disk space

• At least 1.2 GB on the drive on which you install Exchange
  
• An additional 500 MB of available disk space for each Unified Messaging (UM) language pack that you plan to install
  
• 200 MB of available disk space on the system drive
  
• In Exchange 2007 RTM, a hard disk drive that stores the message queue database on an Edge Transport server or Hub Transport server with at least 4 GB of free space
  
• In Exchange 2007 SP1, a hard disk drive that stores the message queue database on an Edge Transport server or Hub Transport server with at least 500 MB of free space
  

For more information about the disk space requirements for the drive that stores the message queue database on an Edge Transport server or Hub Transport server, see Understanding Back Pressure.

Drive

DVD-ROM drive, local or network accessible

None.

Screen resolution

• 800 x 600 pixels or higher
  

None.

File format

Disk partitions formatted as NTFS file systems, which applies to the following partitions:

• System partition
  
• Partitions that store Exchange binary files
  
• Partitions containing storage group files, including transaction log files
  
• Partitions containing database files
  
• Partitions containing other Exchange files
  

None.

Internet Information Services (IIS)

Mailbox

If you have Exchange 2007 installed on Windows Server 2003, you must install IIS by using Add or Remove Programs in Control Panel. If you have Exchange 2007 SP1 installed on Windows Server 2008, you must install by using Programs and Features in Control Panel.

COM+ access (IIS 6.0 component)

Mailbox

If you have Exchange 2007 installed on Windows Server 2003, you must install COM+ access by using Add or Remove Programs in Control Panel. If you have Exchange 2007 SP1 installed on Windows Server 2008, you must install by using Programs and Features in Control Panel.

World Wide Web Publishing Service (W3SVC)

Mailbox, Client Access

If you have Exchange 2007 installed on Windows Server 2003, you must install W3SVC by using Add or Remove Programs in Control Panel. If you have Exchange 2007 SP1 installed on Windows Server 2008, you must install by using Programs and Features in Control Panel.

Hotfix that is described in Knowledge Base article 904639, An access violation may occur when you try to run a 64-bit program that uses the interface remoting component of MDAC 2.8 on a computer that is running Windows Server 2003

Mailbox

None.

Hotfix that is described in Knowledge Base article 904639, Update for Windows Server 2003 x64 Edition (KB904639)

Mailbox

None.

Hotfix that is described in Knowledge Base article 918980, Update for Windows Server 2003 x64 Edition (KB918980)

Mailbox

None.

Remote procedure call (RPC) over Hypertext Transfer Protocol (HTTP) Proxy Windows networking component

Client Access

Note:
Only required on Client Access servers that are providing access to Microsoft Outlook Anywhere. We recommend that you enable at least one Client Access server for Outlook Anywhere access per site.

Note:
It is only supported to use Outlook Anywhere with Outlook 2003 and Outlook 2007 clients.

If you have Exchange 2007 installed on Windows Server 2003, you must install RPC over HTTP Proxy by using Add or Remove Programs in Control Panel. If you have Exchange 2007 SP1 installed on Windows Server 2008, you must install by using Programs and Features in Control Panel.

ASP.NET version 2.0

Client Access

If you have Exchange 2007 installed on Windows Server 2003, you must install ASP.NET version 2.0 by using Add or Remove Programs in Control Panel. If you have Exchange 2007 SP1 installed on Windows Server 2008, you must install by using Programs and Features in Control Panel.

Distributed Transaction Coordinator service

Client Access

The service must be started. For more information, see The Distributed Transaction Coordinator Service Must be Started Before Setup can Continue.

Microsoft Exchange Speech Engine service

Unified Messaging

If you run the Exchange Server 2007 Setup wizard or if you perform setup from a command prompt to install the Unified Messaging server role, Exchange will install the Microsoft Exchange Speech Engine service automatically.

You cannot install the Unified Messaging server role on a computer that already has Microsoft Speech Server installed. You must remove Microsoft Speech Server prior to running Setup. Unified Messaging relies on the Microsoft Exchange Speech Engine service for its speech services, which is installed by the Exchange Server 2007 Setup wizard.

Microsoft Windows Media Encoder

Unified Messaging

If you run the Exchange Server 2007 Setup wizard or if you perform setup from a command prompt, and you do not already have Windows Media Encoder installed, the prerequisite checks during setup will fail. To install the most recent version of Windows Media Encoder, see Windows Media Encoder 9 Series x64 Edition.

Microsoft Windows Media Audio Voice Codec

Unified Messaging

If you run the Exchange Server 2007 Setup wizard or if you perform setup from a command prompt, and you do not already have the Windows Media Audio Voice Codec installed, the prerequisite checks during setup will fail. To install the most recent version of Windows Media Audio Voice Codec, see FIX: Availability of the Windows Media Audio 9 Voice codec for x64-based computers.

Microsoft Core XML Services (MSXML) 6.0

Unified Messaging

If you run the Exchange Server 2007 Setup wizard or if you perform setup from a command prompt, and you do not already have MSXML 6.0 installed, the prerequisite checks during setup will fail. To install MSXML 6.0, see Microsoft Core XML Services (MSXML) 6.0.

Active Directory Application Mode (ADAM)

Edge Transport

Required if you are installing the Edge Transport server role on an Exchange 2007 RTM server that is running Windows Server 2003.

Download the required files at Active Directory Application Mode (ADAM). Accept all default settings during installation. ADAM will be configured for the Edge Transport server role when that role is installed.

Active Directory Lightweight Directory Services (AD LDS)

Edge Transport

Required if you are installing the Edge Transport server role on an Exchange 2007 SP1 server that is running Windows Server 2008.

Use the Server Manager to add the AD LDS role before you install Exchange.

Configure DNS suffix

Edge Transport

Edge Transport servers must have a DNS suffix configured, and you must be able to perform name resolution from an Edge Transport server to any Hub Transport servers and from the Hub Transport servers to any Edge Transport servers. For more information, see Configuring DNS Settings for Exchange 2007 Servers.

NWLink IPX/SPX/NetBIOS Compatible Transport Protocol

Client Access, Edge Transport, Hub Transport, Mailbox, Unified Messaging

Must not be installed.

AppleTalk protocols

Client Access, Edge Transport, Hub Transport, Mailbox, Unified Messaging

Must not be installed.

Outlook

Use one of the following:

• Office Outlook 2007
  
• Outlook 2003
  
• Outlook 2002
  

Outlook Web Access

Client computer with a Web browser installed

Outlook Web Access using Integrated Windows authentication

Client computer with Microsoft Internet Explorer installed

Mobile device

Use one of the following:

• Mobile phones running Windows Mobile 6.1 or later versions
  
• Mobile phones running Windows Mobile 6.0 or later versions
  
• Mobile phones running Windows Mobile 5.0
  
• Mobile phones running Windows Mobile 5.0 with the Messaging and Security Feature Pack (MSFP)
  
• Mobile phones running a non-Windows operating system that are compatible with Exchange ActiveSync
  

Client application that uses Post Office Protocol 3 (POP3)

You must have a client computer that meets the requirements for your specific client. For a list of these requirements, consult the documentation for the POP3 client software.

Client application that uses Internet Message Access Protocol 4 (IMAP4)

You must have a client computer that meets the requirements for your specific client. For a list of these requirements, consult the documentation for the IMAP4 client software.

Microsoft Entourage

Download and read the Microsoft Office 2004 for Mac Resource Kit version 2. This resource kit contains a complete feature matrix and provides details about the versions of Entourage that are supported for Exchange 2007. Information about Entourage 2008 for Mac is available in the Microsoft Office 2008 for Mac Administrator’s Guide.