information store

Information Store is one of the four core components of Microsoft Exchange Server.

What is Information Store?

One of the four core components of Microsoft Exchange Server. The information store consists of two databases that store Exchange messaging content:

  • The public information store, which stores content for public folders hosted on the server
  • The private information store, which stores users’ mail folders, messages, and attachments for users whose home directories are on the server

The information store is implemented as a Microsoft Windows NT service or a Microsoft Windows 2000 service and can be accessed by

  • Messaging clients based on Microsoft Messaging Application Programming Interface (MAPI), such as Microsoft Outlook
  • Post Office Protocol version 3 (POP3) clients, such as Microsoft Outlook Express
  • Network News Transfer Protocol (NNTP) clients, such as Outlook Express

The information store stores its message content using the Exchange message database encoding format (MDBEF). MAPI clients can access this format directly, but non-MAPI clients require conversion of MDBEF format information to their own messaging format - such as Simple Mail Transfer Protocol (SMTP) or X.400.


An Exchange Server can have a private information store, a public information store, or a private and a public information store. This provision for creation or deletion of information stores allows you to load-balance demand on servers by creating dedicated messaging or dedicated public folder servers in your sites.