The calendary server is trying to connect to an IMAP email account to handle calendar invitations. If you are not also running the mail service on the machine, you will have trouble getting the calendar invitations through mail portion working. To get the errors to stop in your logs, just uncheck the "Allow invitations using email addresses" under the iCal service in Server.app.
thanks that has stopped the error logs. I waas running the mail service originally but stopped each service until I was sure what service was causing the issue. I have now unchecked the "allow invitations using email addresses" and the error reports have stopped. Whjat restrictiomns are now in force after unchecking that box....does that mean i had an email address issue? What could ahve been the issue causing the error .....as i just want to learn the "why"?
Thanks for the response Mr Beardsley....error logs now quiet.
In order to invite people to calendar events that are outside your organizaiton, the ical server sends those invitations out using email. There needs to be a account setup on your mail server to both send out these invitations, and to receive them. This system is known as iMIP. The messages you saw in your log was the calendar server trying to log into an IMAP account to check if there were any replies to any invitations sent out using email. If you'd like to get that working, the following page does a decent job of going over it. It is for 10.6 server, but should be pretty similar.