Exchange Server is a mail server and calendaring server developed by Microsoft. It is primarily used for sending, receiving, and storing emails, as well as managing calendars, contacts, and tasks. Organizations often use it to facilitate communication and collaboration among employees. The server can be deployed on-premises or accessed through the cloud via Microsoft 365. It supports various email protocols and integrates with other Microsoft applications, enhancing productivity and streamlining workflows. Security features help protect sensitive information, making it a popular choice for businesses of all sizes.