entry for Kerio MailServer is at the top. Go to the Directory Utility and check that the LDAP Lightweight Directory Access Protocol - A protocol that enables users to access centrally managed contacts.This tool can be found in your WebMail, go to Settings > Integration with Mac. account and run the Auto-configure iCal tool. Remove the iCal CalDAV Calendaring extension to WebDAV that enables you to synchronize calendars.Try following these steps to resolve the problem: If iCal does not Auto-Complete the email addresses of invitees for events.