Microsoft Exchange Server is a collaborative software server from Microsoft, positioned as a rival to the Lotus Notes / Domino server from IBM and recently challenged by a number of Linux-based competitor, first- and foremost Scalix. The use of Microsoft Exchange is very widespread in large corporations using Microsoft infrastructure solutions. Among other things, Microsoft Exchange manages electronic mail, and is thus a popular mail server.
History
Exchange 2000 overcame many of the limitations of its predecessors, Exchange 4.0 and 5.5. For example, raising the maximum sizes of databases and increasing the number of servers in a cluster from two to four. However, many customers were deterred from upgrading by the requirement for a full Microsoft Active Directory infrastructure to be in place. This, in turn, required upgrading a company's servers to Windows 2000. Many customers have opted to stay on a combination of Exchange 5.5 and Windows NT, both of which are now close to their end of service dates.
Current version
The current version of Exchange is 2003 SP 1. It can be run on Windows 2000 Server and Windows 2003, although some new features only work with the latter. Like Windows 2003, Exchange 2003 has many compatibility modes to allow users to slowly migrate to the new system. This is useful in large companies with distributed Exchange environments who cannot afford the downtime and expense that comes with a complete migration.
One of the new features in Exchange 2003 is enhanced disaster recovery, which allows administrators to bring the server online quicker. This is done by allowing the server to send and receive mail while the message stores are being recovered from backup. Better anti-virus and anti-spam protection, by providing built-in APIs that facilitate filtering software, also new is the ability to drop inbound e-mail before being processed. There are also improved message and mailbox management tools, which allow administrators to execute common chores more quickly. On the downside, some of Exchange's collaborative features, such as Public Folders, have been deprecated. Others, such as Exchange Conferencing Server have been extracted completely in order to form separate products. Microsoft now appears to be positioning a combination of Microsoft Office, Live Meeting and Sharepoint as its collaboration software of choice. Exchange is now to be simply email and calendaring.
Exchange 2003 is available in two versions Standard edition, which has a 16GB message database maximum and one database per server, and Enterprise Edition which allows an 16TB maximum database size, and up to 20 databases per server. Enterprise Edition also supports clustering, 4 nodes when using Windows 2000 Server, and 8 nodes with Windows 2003.
Exchange 2003 is included with the Microsoft Small Business Server Product.
Microsoft Exchange Server uses a proprietary RPC protocol, of which only the API is documented (see MAPI), and is used almost exclusively from the Microsoft Outlook client. However there also exists a rival client in the form of a plug-in program for Novell Evolution called Connector . If configured, Exchange accounts can also be accessed through a web browser.
Future
Despite its phenomenal success, the future of Exchange is still unclear. Although Microsoft have said that there will be a new version of Exchange some time in the future, for many months they would not say when it would be released, nor what new features might be in it. A version of Exchange, code named "Kodiak", which was to have been built on top of Microsoft SQL Server was scrapped. As was an add-on, called Exchange Edge Services, which was to have been released in 2005.
Finally, a January 2005 announcement from Microsoft filled in some gaps. The new version, currently called Exchange 12, or E12, is to be released in 2006/07. The new version is to include voice mail integration, better search and support for Web services, as well as support for the (still unreleased) 64-bit version of Windows server.
Licensing
Like Windows Server products, Exchange requires Client Access Licenses which are different and cost more than Windows CALs.
External link
