Microsoft Exchange 5.5

Exchange is a proprietary e-mail and groupware server software from Microsoft for Windows Server. The first version publicly sold was Exchange Server 4.0. The number 4.0 was used as it was a replacement for Microsoft Mail 3.x. At release, unlike other desktop/lan e-mail solutions it featured client/server communications rather than using file sharing, used a powerful messaging protocol, and stored all message and address book information in a database. It eventually evolved to include scheduling and many other functions. The Exchange Client (later Microsoft Outlook) supported rich text formatting, and the ability to create such things as e-mail forms.