This server-side script example allows you to create an In/Out board for your office.
It scans all users MS Exchange mailboxes to collect information about the presence or absence of each user. This information is triggered when the user runs the Out of Office Assistant in Outlook.
PubNotify for Exchange 2000
This application lets to notify users when new item appears in the Exchange public folder. Notification message looks like NET SEND message. The application is Exchange store synchronous event sink. http://victori.hypermart.net/pubnotify.html