Exchange Server 2007 introduced a new programming model by using the Web Services. 

  • It is a programmable interface can be used to provide client access to Exchange store data and information management functions.
  • It handles Simple Object Access Protocol (SOAP) messages sent over HTTP.
  • It will improve the efficiency & programmable access to core business data and functions.
  • It provides heterogeneous servers and clients access to the same business-critical data.

EWS includes the following Web services:

  • Auto discover   Provides configuration information for setting up client applications that connect to mailbox servers.
  • Availability   Provides free/busy data about a user's mailbox. The free/busy data is also used to identify suggested meeting times and provides client Out of Office (OOF) management functionality.
  • Messaging Records Management    Enables the assignment of Managed E-Mail folders to mailbox users.
  • Notification   Notifies the client application of events that are associated with a mailbox. The subscription model can be either push- or pull-based.
  • Synchronization   Provides a one-way synchronized cached copy of a user's folders and items.
  • Exchange Data Service   Provides the following features:
    • Functions to create, update, delete, copy, find, get, and move folders that are associated with a mailbox user, and also the ability to find items that are contained in a folder.
    • Access to the Exchange data store. A client application can create, update, delete, copy, get, move, and send items by using the Exchange Data Service Web service.
    • Ambiguous name resolution.
    • The ability to return the members of distribution list.
    • Access to attachments in the Exchange store.