Exchange Server 5.x

Exchange 5.0 added Outlook Web Access (OWA) to provide remote users access to theri messages via a web browser, Version 5.5 added support for Internet standard messaging protocols, such as post office protocol verison (POP3) and Internet Message Access Protocol verison 4 (IMAP4), and became the version of Exchange that seemed to really make Exchange the messaging platform of choice. If anyone remembes, Exchange 5.x also had a built in chat server.