The standard SMTP protocol is used to communicate to other Internet mail servers.Įxchange Server is licensed both as on-premises software and software as a service (SaaS). This was discontinued in favor of Microsoft Outlook.Įxchange Server primarily uses a proprietary protocol called MAPI to talk to email clients, but subsequently added support for POP3, IMAP, and EAS. Until version 5.0 it came bundled with an email client called Microsoft Exchange Client. Exchange initially used the X.400 directory service but switched to Active Directory later.
The first version was called Exchange Server 4.0, to position it as the successor to the related Microsoft Mail 3.5. It runs exclusively on Windows Server operating systems. Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft.