Microsoft\u00a0provided additional details on Exchange Server 2003, the next version of its e-mail server product, as it made release candidate 1 (RC1) of the product widely available Monday.With the RC1 release, Exchange Server 2003 will be available in Standard and Enterprise Editions, and some changes have been made to the Standard Edition that could result in cost savings for users, Microsoft said. Furthermore, extensive upgrade tools are available to help users upgrade from Exchange 5.5, Microsoft announced Monday at its TechEd conference in Dallas.The Standard Edition of Exchange Server 2003 can run as a dedicated mail server outside a company's firewall. This front-end setup can help with network load balancing when the Web mail feature is used extensively, for example. This feature was available only in the more expensive Enterprise Edition in Exchange 2000, Missy Stern, product manager for Exchange said."With Exchange 2000 Server, if you wanted a front-end server it had to be Enterprise Edition. Now we have added that functionality to Standard Edition so you don't have to purchase Enterprise Edition," she said.Standard Edition is meant for small and medium-sized organizations with between 50 and 5,000 employees. Enterprise Edition is for organizations with 5,000 or more employees or for companies with large storage or clustering requirements. Clustering is not supported in the Standard Edition and storage is limited.Exchange 2000 Server was released in October 2000. Around 130 million client licenses have been sold so far, Stern said. Exchange competes with products including Lotus Notes from IBM.Even though Exchange 2000 Server has been available for a while, Microsoft estimates that between 40% and 60% of its customers still run Exchange 5.5 on the Windows NT 4.0 platform. A host of upgrade tools are included with Exchange Server 2003 to help customers move up."We listened to all the feedback from Exchange 5.5 customers migrating to Exchange 2000, and we have wizards and tools to give them detailed deployment guidance," Stern said. Support for Exchange 5.5 will be available through the end of the year; after that a customer will have to buy extended support if needed, she said.Exchange Server 2003 runs only on Windows 2000 Server or Windows Server 2003, so customers running NT 4.0 also have to upgrade their operating environment when moving to a newer e-mail server."These new upgrade tools will help you doing both," Stern said.About 50,000 testers participated in the second beta of Exchange Server 2003 that was launched in January. A 120-day evaluation version of RC1 will be available for free download from Microsoft's Web site starting Monday.RC1 will be directly upgradeable to the final release of Exchange Server 2003. Users wanting to test Exchange Server 2003 and start planning their deployment can do so using RC1 and install the final code when it becomes available, Microsoft said.The final version of Exchange Server 2003 is expected to be available in about six to eight weeks for customers who buy volume licenses and in a retail version in the fourth quarter, Microsoft said.Pricing for Exchange Server 2003 has not been announced. Exchange 2000 Server Standard Edition is priced at $700, and the Enterprise Edition costs $4,000. The price is for the server license only, and client access licenses are extra, Stern said.