Introduction

 In the fourth incarnation of Microsoft’s premier messaging system, the guys and gals in Redmond have decided to pull out everything that they could to make this THE corporate email solution.  Microsoft Exchange 2000 has got a lot of claims to fame; after all it was the first application to take full advantage of Active Directory.  New features have been placed to simplify your job of management and recovery.  It helps the end-user get to the information that they need, be it email or documents, as soon, and in as many ways, as possible.  There are a bunch of things that you need to do to get to that point, but after this brief review you’ll see if this is the messaging system for you and what it should take to get you there. Did you know that Exchange is built on SQL Server?  It has been for quite some time now.  Think of the evolution of SQL Server and the evolution of Exchange.  SQL 2000 supports multiple Instances of a Server on a single computer, Exchange supports Multiple Mail Stores.  SQL 2000 supports XML, as does Exchange 2000.  SQL is a transactional database application, Exchange uses transaction logs.

New Features

• Built in Instant messaging – MSN Messenger can be deployed in your network to allow you users to send instant messages to each other without doing it through email.  No more single-line messages taking up your mail server…
   
• IP Multicast and H.323 capabilities – If you want to do video conferencing, Exchange has the ability to switch between IP Multicast and H.323 Gateways; this will be discussed more in depth later in the article.
   
• Multiple Mail Stores – Just imagine the possibilities.  If you could separate the users across multiple mail stores, you could restrict basic users to have a maximum of 50 MB per mailbox and give Executives no limit on the same server.  This functionality was available in 5.5, but you had to configure the limit on the server and bypass it on a user-by-user basis.  Now, you only have to do it twice, once on each mail store.  You could also backup the Executives every night and the regular users once a week.
   
• Improved Outlook Web Access – Do you like the interface of Microsoft Outlook 2000?  Well, OWA for Exchange 2000 looks VERY close.  Microsoft now uses XML instead of ASP pages to retrieve information from the Information Store which increases performance quite a bit.
   
• Active Directory Integration – Exchange adds some attributes to user objects as well as Group objects to allow you to configure them from one window instead of several ones.  Security Groups in Windows 2000 can now be mail-enabled as well.
   
• Front End and Back End Servers – Front End Servers handle client requests and Back End servers store email.  This method of distributing the load helps to increase performance and system stability because clients never directly access the servers with actual data; so if a Front End Server experiences a failure, another Front End Server can handle the requests without the clients seeing any downtime.
   
• Enhanced Cluster Serving – Multimaster clustering allows client requests to occur on multiple servers until one fails.  Previously Exchange supported fail-over clustering; this method required that one server be essentially dedicated to a dummy role until a failure actually occurred, resulting in underutilized servers.
   
• Web Store – The Web store is the central repository where all information, Public Folders and Private Folders, is kept in Exchange Server.  If you go to your Exchange Server and open up Windows Explorer, you will see an H drive letter.  This drive letter is mapped to your Exchange Private and Public Information Store Database files and it allows you to navigate through them as you would your normal file system.  A user can also access all of his or her information just by typing the path in the Internet Explorer address bar.  For example, if a user wants to access a File called Employee.doc in the HR public folder, he or she could simply type http://exchangeserver/public/HR/employee.doc and the file would open in Microsoft Word.  This allows amazing support for Developers wanting to create collaborative applications with ASP and XML coding on top of IIS.
   
• Web Forms – These are similar in functionality to the Web Store as far as access goes.  A developer could develop a customized form with FrontPage and post it in Exchange, then all of the clients could access that form to fill out their expenses just by typing the URL of the form.
   
• Database File Structure – Information Store Databases now consist of two Database files, an EDB file (Exchange Database) and an STM file (Streaming).  The EDB file holds all Exchange Rich text formatted messages, like email messages.  The STM file hold non-exchange files like video, audio, voice, http files and so on.  This allows Exchange to not have to convert files from their native format into MDBEF format like in previous versions of Exchange where there was only one file.  This accommodates for increased performance because Exchange can work with only one file for email or MAPI requests and one for everything else.
   
• Single Instance Store – If you send a 20 MB message to ten users on one Server, Exchange stores that message one time and creates pointers that it sends to the recipients, cutting down on space taken up in the Database.
   
• Routing Groups – These replace Sites in Exchange 5.5.  A routing group is defined by a collection of well-connected Exchange Servers that require full-time connectivity.  Exchange now communicates with all servers in a routing group using SMTP which is more tolerant of low-speed, unreliable bandwidth situations.
   
• Link State Algorithm – This allows Exchange to be more intelligent when it comes to determining the path that a message must take to reach its destination.  It essentially work like the OSPF protocol works with routers; exchange can query other servers to find out when certain connectors are down and choose another path before the message is sent out from the server.  It would be nice if in future versions Microsoft could connect this to OSPF compliant routers to determine where links are down physically on the Internet as well…