Fair Overview of Exchange 2007 Server Roles

Exchange 2007 has been splited based on Server Roles so if you require any specific function on a server then it can be placed on indivudial server based on your requirement, Exchange architecture, performance, management or your organization's policies.

We used to set Front-End and Back-End server roles in Exchange 2003 but Exchange 2007 introduces five roles for an Exchange organization.

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

Brief overview of each roles are below.

1. Mailbox Server

• Use for holding all Exchange Database - Mailbox & Public Folder (optional).
• It should be part of Domain & AD.
• 50 Storage Groups & 50 Mailbox Stores in each Storage Groups.
• STM File architecture has been removed.
• Proper backup recovery plans should be in place for High Availability.

2. Hub Transport Server

• Responsible for internal mail flow. (Same like Bridgehead in Exchange 2003).
• It should be part of Domain & AD.
• Incoming Mail Flow : Mailbox <- Hub Transport <- Edge Transport <- Internet.
• Outgoing Mail Flow : Mailbox -> Hub Transport -> Edge Transport -> Internet.
• Hub Transport can be placed instead of Edge Transport and can act for the similar function.
• Transport Agents, AntiSpam, AntiVirus can be enabled.
• Disclaimer can be set on.
• One Hub Transport role should be placed at a AD Site for good architecture.

3. Edge Transport Server

• Should be placed in Edge of your organization ( in workgroup / DMZ / perimeter ).
• Should NOT be a member of Domain & AD.
• ADAM ( Active Directory Application Mode ) provides AD information to Edge Transport server with help of Exchange component "EdgeSynch" by creating one way synchronization (from Domain to Edge Server).
• ADAM & EdgeSynch provides AD recipient information & SPAM filtering efficiency.
• Provides better Anti-spam and Anti-virus protection with help of connection filtering, content filtering, recipient filtering, SenderID, sender and IP reputation.
• Edge Transport Rules to protect Exchange environment, based on SMTP and MIME addresses, words in the subject and message body, and SCL rating.
• Address rewriting feature allows to modify the SMTP address on in/out-bound mail.

4. Client Access Server

• Client Access Server was known as a Front End in Exchange 2003.
• It should be part of Domain & AD.
• Handles all the milbox access request comes from

1. Outlook Anywhere - Application (like Outlook 2003 or 2007).
2. MAPI, POP3 or IMAP4 client - like Outlook Express and Eudora
3. Exchange ActiveSync - Mobile devices ( like Windows Mobile 5 Smartphone, pocket PC or any other device).
4. Outlook Web Access (OWA) including Sharepoint & UNC access.

• Clietn Access provides Autodiscover mailbox location for Microsoft Outlook 2007.

5. Unified Messaging

• Merge VoIP environment with Exchange.
• Requires VoIP Gateways or PBXes to connect with Exchange.
• Access Voice Mails by using OWA.
• Outlook Voice Access provides below things.

1. Listen voicemails.
2. Forward or reply to messages.
3. Get emails automatically & read via text-to-speech interface.
4. Get calendar information.
5. Accept or reply to meetings.
6. Set voicemail Out-of-Office messages.
7. Access or dial contact.
8. Reconfigure the lite settings on the mailbox.