Exchange 2007 de-emphasized Exchange Event Sinks in favor of a new notification system which allows an application to receive notifications about changes made to items on a public folder or mailbox folder. There are two types of notifications: Pull and Push. With pull notifications, the calling application is responsible to get changes back from the server (it has to poll the CAS role for changes). Push notifications on the other side use Web Services to call into an external application. There are a restrictions where this does not work (for example firewalls blocking traffic), but otherwise they work really well.

Compared to the WebDAV notifications that where available in earlier versions of Exchange, they have the advantage that the external application gets specific information about the event: Which item has been modified, created, deleted?

However, it’s rather complicated to completely implement a listener for these notifications. Therefore, I have created a wrapper which uses WCF to listen for incoming notifications.

The whole package is available from CodePlex (http://www.codeplex.com/exchangenotification), and there is a list of features. Only the source and a small help file for now, but I will add samples over time.

If you have feedback, please use CodePlex Discussions or send me a mail by using the contact form.