Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2012-05-09

In Microsoft Exchange Server 2010, the Mailbox server role is one of several server roles that you can install and configure on a server running Windows Server 2008. The Mailbox server role is the most common server role and is at the core of an Exchange organization. Servers on which the Mailbox server role is installed are called Mailbox servers.

Mailbox servers perform the following functions:

Looking for management tasks related to Mailbox servers? See Managing Mailbox Servers.


Mailbox Server Interactions

Coexisting with Other Server Roles

Server Role Configuration

Services and Port Executables

Planning for Public Folders

Mailbox Server Interactions

The Mailbox server must interact directly with the following:

  • Active Directory

  • Client Access server

  • Hub Transport server

  • Unified Messaging server

  • Microsoft Outlook clients

Mailbox Server Role Connections

The following process applies:

  1. The Mailbox server uses LDAP to access recipient, server, and organization configuration information from Active Directory.

  2. The store driver on the Hub Transport server places messages from the transport pipeline into the appropriate mailbox. The store driver on the Hub Transport server also adds messages from a sender's Outbox on the Mailbox server to the transport pipeline. To learn more about the store driver, see Understanding Moderated Transport.

  3. The Client Access server sends requests from clients to the Mailbox server, and returns data from the Mailbox server to the clients. The Client Access server also accesses OAB files on the Mailbox server through NetBIOS file sharing. The types of data that the Client Access server sends between the client and the Mailbox server include messages, free/busy data, client profile settings, and OAB data.

  4. The Unified Messaging server retrieves e-mail, voice mail messages, and calendar information from the Mailbox server for Outlook Voice Access. The Unified Messaging server also retrieves storage quota information from the Mailbox server. To learn more about Outlook Voice Access, see Understanding Outlook Voice Access.

  5. Outlook clients inside your firewall access the Client Access server to send and retrieve messages. Outlook clients outside the firewall can access the Client Access server by using Outlook Anywhere (which uses RPC over HTTP). However, Outlook clients that are viewing or modifying public folders access the Client Access server by using RPC over TCP. To learn more about Outlook Anywhere, see Understanding Outlook Anywhere.

  6. The administrator-only computer retrieves Active Directory topology information from the Microsoft Exchange Active Directory Topology service. It also retrieves e-mail address policy information and address list information.

  7. The Client Access server uses LDAP or Name Service Provider Interface (NSPI) to contact the Active Directory server and retrieve users' Active Directory information.

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Coexisting with Other Server Roles

The Client Access server role, Hub Transport server role, Mailbox server role, and Unified Messaging server role can coexist on the same computer in any combination. When considering what combination of server roles to deploy, you should base your decision on capacity and performance planning and on your security and availability requirements. For more information, see Mailbox Server Storage Design.

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Server Role Configuration

To configure the Mailbox server role, use the Set-MailboxServer cmdlet in the Exchange Management Shell. To retrieve Mailbox server role settings, use the Get-MailboxServer cmdlet. For more information, see Configure Mailbox Server Properties.

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Services and Port Executables

When you install the Exchange 2010 Mailbox server role on a computer running Windows Server 2008, the services and port executables shown in the following table are installed. The Microsoft Search (Exchange Server) and Microsoft Exchange Monitoring services are set to start manually. All other services are set to start automatically.


Service short name Service name Associated executable Port name


Microsoft Exchange Information Store




Microsoft Exchange Active Directory Topology




Microsoft Exchange Mailbox Assistants




Microsoft Exchange Search Indexer




Microsoft Exchange Service Host




Microsoft Exchange Monitoring




Microsoft Exchange System Attendant




Microsoft Exchange Mail Submission




Microsoft Search (Exchange Server)




Microsoft Exchange Transport Log Search



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Planning for Public Folders

Before you deploy public folders, it's important to familiarize yourself with the functionality that public folders provide to make sure that the public folders meet the needs of your organization.

Exchange public folders are intended to serve as a repository for information that's shared among many users. You should use public folders when your business requires data replication to multiple servers. Access to public folders is integrated with regular mailbox access through the MAPI protocol. For more information about public folders, see Understanding Public Folders and Managing Public Folders.

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