Features in Exchange 5.0, 2000, 2003, and 2007
Exchange 5.0 introduced the first version of Outlook Web Access (OWA), which initially was more appropriately named Exchange Web Access. It also added formal SMTP and LDAPv2 to the product. Exchange 5.5 maintained the same style administrative interface and updated LDAP to v3 and added NNTP.
For the next version, (v6.0) naming changed to incorporate the calendar year and Exchange 2000 underwent a major facelift. Directory service functionality was now being served by the new Windows Active Directory. SMTP was handed off to Internet Information Services (IIS) with Exchange extensions. Exchange 2000 Instant Messaging was also introduced as an IIS application for corporate IM.
Exchange 2003 (v6.5) improved upon many features of Exchange 2000, including a richer AJAX OWA client and a recovery storage group for restores. Client access features evolved as well with ActiveSync and Outlook Mobile Access (OMA) for mobile device users and RCP/HTTPS and Exchange Cached Mode for Outlook 2003 users. Instant Messaging was removed to serve in a separate application, Live Communication Server, now expanded to Office Communication Server.
Exchange Server 2007 (v7.0) again introduces big changes throughout the application from architecture to appearance. Exchange 2007 is role-based allowing administrators to install only the roles that are required for that server. This is also the first Microsoft application to take advantage of Microsoft’s new extensible scripting language, PowerShell (nee Monad). Unified Messaging is also a significant feature addition, integrating with Office Communication Server and PBX/VoIP systems.
Microsoft now releases cumulative updates in between service pack releases for Exchange Server. These updates are called Update Rollups. They are numbered releases expected every six to eight weeks and apply to specific service pack levels for Exchange Server. The current release is Exchange Server 2007 Service Pack 1 with Update Rollup 2.