Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems. ... The standard SMTP protocol is used to communicate to other Internet mail servers. Exchange Server is licensed both as on-premises software and software as a service (SaaS).

Is Exchange a server role?

The Exchange 2007 Mailbox Server role hosts mailbox databases where user and resource mailboxes are stored. This server role hosts the Public Folder database, used by organizations for the sharing of documents, calendar, contact, and task data, as well as for archiving distribution lists.

How do Exchange servers work?

When you use an Exchange account, your email messages are delivered to and saved in your mailbox on the Exchange server. Your contacts and calendar are saved there, too. When your business or school sets up their Exchange server, they choose what method your Exchange account uses to access email on the server.