Calendar Server requires users, groups and resources to have the mail attribute, which contains the email address of the user, group or resource. This enables people to search for calendars using either an email address or a calid. When you create new users with Delegated Administrator, it adds the mail attribute automatically. This happens even if the user has not been assigned mail service. However, if your users and resources were created in a version of Calendar Server when the mail attribute was not required, you might have to add the mail attribute to your existing user and resource LDAP entries.
Adding the mail attribute does not enable email notifications for user calendars.
Calendar Server does not support email notifications for group, or resource calendars.
To enable email notification for user calendars, add the following two attributes to the user’s LDAP entry: