iCal supports email notification. The email capability is an optional feature.
A couple of basic requirements to use the Email notification capabilities.
1. iCal must be run on an NT/2000/XP/2003
2. An SMTP server must be accessible for sending Email
There are several features wrapped around email notification.
The Email Configuration
page is were you can enable Email for the iCal system. On this page you
will define the SMTP mail server and a few other optional values.
When the email system is enabled, the main administration screen for each calendar
will have a link to an Email Notification setup form. This will allow custom Email
configuration for each calendar.