Exchange Server is a messaging platform that stores information in fault-tolerant, transaction-based databases before writing it to the database. Besides data storage, it enables multiple functionalities to the users, such as email, setting calendars, contacts, and tasks. It includes support for almost every web browser, including Internet Explorer, Firefox, Safari, and Chrome, which enables you to stay connected from anywhere, with anybody in your contact list, at any time.

Two Main Database Components of MS Exchange Server:

  1. Information Store: It is the primary component of MS Exchange Server that is responsible for database management. It is comprised of two distinct databases, 'Pri.edb' and 'Pub.edb'. The private information store database, Priv.edb is used for user mailboxes, whereas the public information store, Pub.edb is used to keep track of data in public folders. 
  2. JET Database Engine: It performs caching of disk by continuously moving fixed-size data pages in and out of memory. This helps to enhance the performance and productivity of the Exchange Server. The database engine also organizes the structure of the disk for Exchange Server.  

When a user receives a message, the Messaging Application Programming Interface (MAPI) makes a call to the Information Store (IS), which indeed calls the JET database engine. After this, the required changes are written to the disk.