With many of our clients now considering an Exchange 2007 migration, we thought we would take this opportunity to give you all a quick heads up about the requirements and features/benefits of such a move. As you'll see, there's quite a bit to consider.

Firstly, and most importantly - Exchange 2007 only comes is a 64bit production version.

Minimum system requirements:

• x64 architecture-based computer with Intel processor that supports Intel Extended Memory 64 Technology (Intel EM64T) or AMD processor that supports the AMD64 platform.
• 2Gb RAM Minimum (assume an extra 5Mb per mailbox).
• 1.2 Gb of free hard drive space.
• Windows Server 2003, Standard x64 Edition and above (Not Windows 2008 though… “Longhorn”).

The above should simply be looked at as “It has to be 64bit”. If you've bodht a server in the past 12 months, you're probably ready to go, but it's worth a check to make sure. While there is actually a 32bit version of Exchange 2007 available, this can only be used for testing and not production, because the product is time bombed.

As with the installation of any new product, features will differ somewhat from the predecessor. There has been a little bit of confusion from the exchange community as to what will actually be supported and what won’t be. Microsoft have attempted to resolve this by creating two categories: Deemphasised Functions and Features specifically no longer included. Deemphasised Functions should be treated as supported but no longer developed, and as such customers who use these functions should see the writing on the wall, and should consider using alternate technologies in the future.

The list is quite surprising of what’s going, going gone.  (Full listing here - http://technet.microsoft.com/en-us/library/aa998911.aspx )

Deemphasised features:

• Public Folders! Whilst they are still supported in Exchange 2007, newer technologies are being introduced to replace them; such as sharepoint and other portal technologies. What's really surprising is that until Exchange 2007 SP1 is released, you can't manage public folders through the GUI without using the Windows Powershell or Exchange 2003 GUI.
• Collaborative Data Objects technologies such as CDOSYS, CDO 1.2.1 and CDOExM are being deemphasised. Application that use these API’s should be getting a rewrite to use the new Transport Agent API or Exchange Web Services API for continued support after Exchange 2007.
• Functions provided by Exchange WebDAV extensions are now provided by the Web Services API
• The Exchange OLEDB functionality is also now provided by the Web Services API.

Features no longer included:

• Exchange 5.5 interoperability is no longer included.
• OMA or Outlook mobile Access, the lightweight browser based access for WAP based mobile phones is not available.
• Non-MAPI public folder hierarchies are no longer available.
• Public Folder access via Outlook Web Access, NNTP or IMAP4 is no longer available.
• NNTP features have been cut from Exchange 2007 completely.
• Mailbox databases no longer have a streaming database file (STM file). All Mail regardless of it original source is stored in the EDB database file.
• RUS (Recipient Update Service) has been replaced. Email addresses and memberships can be altered at the time of creation or with the Exchange Management shell.
• X.400 connectors are no longer available (you will still get an X.400 address and AD however).
• ExMerge can no longer be run from the Exchange 2007 Server Console.
• Two node active-active clustering cannot be configured. Exchange 2007 requires Active-Passive clustering.
• POP3 and IMAP4 configuration is now performed through Exchange Management Shell rather than the GUI.
• Exchange Installable File system ExIFS is no longer available. (M: drive on Exchange 2000).

New features:

• The Exchange Management Shell is a new task-based command line shell and scripting language for system administration. You can use the Exchange Management Shell to perform every task that the Exchange Management Console can perform, and additional tasks that cannot be performed in the Exchange Management Console.
• Exchange 2007 lets you create as many as 50 storage groups per server. Although a storage group can contain as many as 5 databases, there is a limit of 50 databases per server.
• When multiple Exchange 2007 computers that are running the Hub Transport server role are deployed in a site, mail flow between Hub Transport servers and Mailbox servers is automatically load balanced and does not require any additional configuration by the administrator. If a Hub Transport server (formerly known as a bridgehead server) is unavailable because of a failure or scheduled maintenance, failover to the other Hub Transport servers is automatic.
• Exchange 2007 includes three built-in features that provide high availability for Mailbox servers:
• Local Continuous Replication (LCR)
• Cluster Continuous Rreplication (CCR)
• Single Copy Clusters (SCC)
• The continuous replication features use log shipping to create a second copy of a production storage group. In an LCR environment, the second copy is located on the same server as the production storage group. In a CCR environment, the second copy is located on the passive node in the cluster.
• Exchange 2007 includes many new messaging compliance features. You can use the policy and compliance features of Exchange 2007 to apply rules to messages that are sent and to enforce retention requirements for stored data. The new Messaging Records Management (MRM) feature in Exchange 2007 helps users and organizations retain the messages that they need for business or legal reasons.
• Exchange 2007 includes several improvements to the suite of anti-spam and antivirus features that were introduced in Microsoft Exchange Server 2003. In Exchange 2007, the anti-spam and antivirus features provide services to block viruses and spam, also known as unsolicited commercial e-mail, at the network perimeter.
• Roles – The server can now be split into specific roles for larger deployments
• Mailbox
• Client Access
• Hub Transport
• Unified Messaging
• Edge Transport – for my money this is one of the more exciting roles as hosting an exchange server in the DMZ has always been a tricky exercise with regards to how much access the server needs to the internal network. The Edge Transport role now redefines this as it maintains a subscription to the internal AD and a read only copy of the directory. It also has the inclusion of being the placement for a lot of the forefront security options which Microsoft are venturing into such as SPAM, Virus and content filtering.

For now that’s it. Keep an eye out for additional news on some best practices for adopting Exchange 2007, such as client recommendations and migration strategies.