What's New and Cool in Exchange 2007

As you can see from the long list of new, changed, and discontinued features above, Exchange 2007 is a MAJOR update.  It would be wise to continue to read up on it and start getting familiar with it in your lab or Microsoft's on-line labs.  If you haven't seen Microsoft's on-line labs you must check them out.  They are Virtual Server sessions that can be access using Internet Explorer and are created automatically for a user when they access them.  Most of the labs provide a guided walk though of a product for 30 minutes to an hour and a half.  After that time you are disconnected, if you reconnect the lab will start over.  These are great because you don't have to spend any time setting up a lab with multiple servers and fooling around with trying to get beta or release code working correctly.  Check them out at: http://www.microsoft.com/technet/traincert/virtuallab/default.mspx and http://www.microsoft.com/learning/exchange2007/default.mspx. ?At the time of this writing no virtual labs had yet been created for Exchange 2007 but they should be soon. ?Many were used at TechEd 2006, and I suspect those will be published to the web before long.  There were two eLearning courses, which are currently free and available at the time of this writing on Exchange 2007.  One is on "What's New" and the other is on the architecture in Exchange 2007.

Details on Major Changes

64 Bit Support

One of the biggest factors limiting Exchange scalability is the amount of memory Exchange can access.  In Exchange 2003, and earlier, it is limited to around 3GBs.  While this may seem like a large amount, think about the size of the Exchange database and how they have grown since Exchange 4.0.  Today Exchange attempts to cache data in RAM but is unable to do so efficiently when many users are accessing the same server. This is because the data being access is very random in nature.  With Exchange 2007 and its requirement for 64 bit hardware, Exchange will no longer be limited to 3GB of RAM.  For large deployments, Microsoft recommends 10GB+ on a single Exchange server.  With larger memory comes a larger amount of data that can be cached in RAM.  This in turn reduces the I/O operations, or IOPS, to the storage system.  This will allow servers to be configured with larger and cheaper disks, like SATA2 drives, instead of having to worry about the number of spindles and purchasing 15K SCSI disk to meet IOPS requirements.  Microsoft has seen a 70% decrease in IOPS in Exchange 2007 running on 64 bit when compared to Exchange 2003 with the same number of mailboxes and load.  For more information read the FAQ topic on this subject: http://www.microsoft.com/exchange/preview/faq.mspx#E6C.  Today with Exchange 2003, I have done several deployments where a single Exchange server was hosting over 4,000 mailboxes in a multi-node cluster.  With Exchange 2007, I suspect this can be increased to at least double this amount with enough CPUs (quad cores should be out by the time Exchange 2007 is released) and RAM (32GB+).

Server Roles

In Exchange 2003 there were basically two type of Exchange servers, Front-End and Back-End.  You could configure an Exchange 2003 server to only act as a bridgehead but all of the Exchange binaries and services were still installed on the server.  In Exchange 2007, when you run setup you have to choose what roles the server will host, see Figure 1 - Exchange 2007 Server Role Selection.  With the exception of the Edge Transport role all of the roles can be installed on a single server.  The Edge Transport role is a special role that should only be installed on a server in your DMZ or directly connected to the Internet.  The Edge Transport role should also only be installed on a stand-alone member server for maximum security.

Figure 1 - Exchange 2007 Server Role Selection

The Hub Transport role, similar to a bridgehead server in Exchange 2003, is the ?hub  for all Exchange message traffic.  All e-mail sent between users, even if they are on the same server and database, will be sent though a Hub Transport server or role.  This role provides the support or agents in Exchange 2007 to do message filtering based on message content and policies defined in Exchange.  These polices are similar to the Inbox Rules Wizard in Outlook, but always runs on the Hub Transport server.  The Edge Transport role also supports agents, but will normally be limited to anti-spam and anti-virus filtering.

The Client Access server (CAS) serves multiple functions in Exchange 2007.  When Outlook 2007 is used, Outlook will contact the closest Client Access server (CAS) to determine the closest CAS server to the user's mailbox server.  This will allow roaming users to get connected to their mailbox server in the most efficient manner.  Outlook 2007 will use bandwidth and network friendly communications, like HTTPS, to talk to the CAS server closest to the user?s mailbox server.  Then the CAS server will communicate with the mailbox server using MAPI over RPC.  Because of this there should normally be a CAS server located on the same LAN as the mailbox servers.  The CAS server provides mailbox access for ActiveSync, POP3, IMAP4, Outlook Anywhere (RPC over HTTPS), and Outlook Web Access.  Finally, the CAS server provides the programmability interfaces for web services and Web Parts, for SharePoint.  At smaller sites, the CAS and Mailbox server roles will probably be installed on a single server, quite possibility with the Hub role also since a Hub server must exist in any AD site that contains a mailbox server.  The CAS server also runs the Calendar Concierge Services, covered later.

Calendaring

I am sure everyone reading this document has seen a meeting invite that says "Meeting request is out of date."  With Exchange 2007 this will be a thing of the past.  In Exchange 2007, a new process called Calendar Attendant will be responsible for keeping track of all meetings and making sure all meeting request are always up to date!  In addition, it will automatically place new meeting requests, that have not yet been accepted by a user, as tentative on the user's calendar.  This should help prevent users from getting double booked for meetings when they are not at their desk.  The Calendar Attendant will also make sure that any minor updates, like attendees, location, and details, are automatically updated without having users re-accept a meeting.  These features will help to greatly reduce ?meeting noise  and reduce user confusion.  Lastly, it will let meeting organizers know if a meeting request has been forwarded to other users. This is done by an email notification to the organizer and by updating the meeting attendees on the organizer's calendar.

The process to book meetings has also been redesigned.  When booking meetings in Outlook 2007 and OWA 2007, users will be shown a color coded calendar that shows dates in shades of blue based on how ?good  that day would be for the meeting you are attempting to book.  Based on attendee and resource availability, a day's color will range from ?white  to indicate there is a slot on the day where everyone is available to ?dark blue  when there are conflicts with most meeting attendees.  In addition, Outlook 2007 will suggest meeting times and dates based on attendee availability and work hours.  At the top of the list will be the earliest time when all or most attendees will be available. ?These suggestions are also color coded to indicate the best times.

Resource booking has also gotten a MAJOR update.  Administrators will now be able to create real resource mailboxes that have properties on them that will help users find and book them correctly.  Exchange and Outlook will use these properties to make sure a resource is always booked as a resource.  New schema extensions will be used to identify a mailbox not only as a resource but if it is a room or equipment.  These extensions can also be used to store the size of the room, how many of the items exist, if it can be booked multiple times, maximum meeting duration, hours available, who can book it, and more.  The Resource Booking Attendant (RBA) will take over the responsibility of accepting meeting invites to resource mailboxes.  The RBA will take into account the settings defined on the mailbox before accepting the meeting request and will send out custom response messages per resource, if defined.  All of these new services are provided by the CAS role.

Free/Busy has also been changed and improved.  First off, Free/Busy information is no longer stored in Public Folders by Exchange 2007 servers.  Free/Busy information is now published as a web service.  The Availability Web Service retrieves live free/busy information from mailboxes in the same forest, different forest, and Public Folders (if running in a mixed environment).  This will help eliminate major delays seen in Exchange 2003 and earlier where Free/Busy was only updated on a scheduled basis and then was further delayed by Public Folder replication between Exchange servers.  Users  working hours, meeting subjects, meeting details, and attendees are all now included in the free/busy information.  Users and administrators can now control what, if any, free/busy information is published.

What?s New and Cool in Exchange 2007