Understanding of Exchange Server Architecture

In this article we are going to look into the architectural design of Exchange Server 2010 and its roles and functionalities.


Exchange Server 2010In my previous article, we have seen the evolution of the Exchange server and its history. As I mentioned there, we are going to concentrate of learning the concepts from Exchange 2010 onwards. Before I begin to show you the installation, configuration, Exchange recovery and all, I would like to explain its architecture and its role. This will be helpful for you to co-relate my other articles and learn the concepts easily and quickly.

Active Directory Dependency

Active Directory is the service that is coming along with Windows server and it’s a core component in most of the enterprises. User, computer, groups, domain and many more management can be done using this core service. I assume you have heard about this service. As this series is concentrating on Exchange server, I am covering AD concepts. The reason I brought this topic in this article is Exchange server is completely dependable on Active directory service.

It has its own schema. So before installation of Exchange server we need to prepare the AD schema. All the configuration details will be stored under configuration partition. In case of any disaster, we can recover it using this partition information. It is always advisable to take system state backup of your Active directory.

Different Type of Roles:

Roles In Exchange 2010 ServerThere are five roles in Exchange 2010 server. They are namely

  • Mailbox role
  • HUB transport role
  • Client Access Server role
  • Edge role
  • Unified Messaging role

Mailbox role: This role will maintain all your data which means your emails, calendars, tasks, notes, etc., will be stored here. It will have a database which is kind of a container. Inside that database, user mailboxes will be stored. Whatever changes you are making will be recorded as a log and then it will be played into that database. If you don’t understand, please do not worry as we will see a lot more in-depth details in upcoming articles.

HUB transport role: This will handle all your mail flow both internally or externally. For example, if you are sending an email to your colleague who is within the organization and also you are CC’d to your Gmail account. The mail will first reach this HUB server and it will categorize it and then submit it to the respective recipients. Internal emails will be submit to the recipient mailbox and external emails will be submit to the respective external mail server, in this case Gmail server.

Client Access Server (CAS) role:  This role will handle the requests coming from all the clients namely Outlook, Outlook Web Access, ActiveSync, Outlook Anywhere. This will act as a gateway to all the requests and post authentications which will be redirected to the backend server called “Mailbox server”. RPC (Remote Procedure Call) service is the core service which will help to achieve the above task.

Edge role: You might have heard the term called “SPAM” which is very annoying in today’s world. To protect your mailbox from hacking and avoid spamming or spoofing, we can use anti-spam technologies. There are lot of well know third party companies provide this service, however Microsoft got their own technologies and it is coming as a part of inbuilt functionalities in Exchange as a role. That is called “Edge role”.

Unified Messaging (UM) role: Unified messaging role will be helpful to route all the voice mail to the user mailbox. If anyone leaves a voice mail to specific extension, then unified messaging will route that voice mail to its respective mailbox. Most of the companies will use third party service for this as they have enriched features. Cisco is one of the giants in this market.


Now I guess you would have understood the basic architecture and functionality of Exchange server. I thought of covering this topic before we jump into the installation and configuration, so that you can understand why we are installing those roles. We are going to see much deeper about these roles in upcoming articles, so stay tuned!!

Author Introduction

Sophia Mao is a data recovery expert in DataNumen, Inc., which is the world leader in data recovery technologies, including outlook recovery and word recovery software products. For more information visit www.datanumen.com

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