Microsoft Exchange Client was a multi-purpose messaging product useful for managing e-mail.[1] It was the native and bundled client for Microsoft Exchange Server up to version 5.0, later superseded by Microsoft Outlook.
The original Windows 95 "Inbox" client also used MAPI and was called "Microsoft Exchange". A stripped down version of the Exchange Client that does not have support for Exchange Server was released as Windows Messaging when Exchange Server was released to avoid confusion and later vanished as part of Windows 98 and later. That was because of the move to email standards such as SMTP, IMAP, and POP3, all of which Outlook Express supports better than Windows Messaging.
Exchange Client was replaced by Microsoft Outlook, which was part of Microsoft Office 97 and later.[1] Outlook 97 had different versions (latest is 8.04, a part of Office 97 SR-2), and these were released as part of both Office 97 Service Releases and new Exchange versions. When Outlook 97 was released, Exchange Client 5.0 was still in development and to be later released as part of Exchange Server 5.0, primarily because Outlook was not available for platforms other than Microsoft Windows yet. Later, in Exchange Server 5.5, Exchange Client was removed and Outlook made the only Exchange client. As part of Exchange Server 5.5, Outlook was released for other platforms.