Calendar Server defaults to non-hosted domains. If you are using Calendar Server and Messaging Server in your Java Enterprise System deployment, you should use hosted domains.
You can enable or disable hosted domains for your installation by editing the ics.conf file.
Edit the ics.conf file as follows:
service.virtualdomain.support="yes" (the default is "no".)
Restart Calendar Services.
For a list of all the ics.conf parameters necessary to implement hosted domains, see Setting up a Hosted Domain Environment.