CSA agents installed on the agent host in the target domain are not synchronizing calendars.
The following error repeated in the log for every mailbox:
"9/5/2012 10:01:16 AM CADQueue::NextItem Informational 4511 Starting to process item '/o=Domain/ou=First Administrative Group/cn=Recipients/cn=amano' (Collection 'Exec', PST: '009BA1E2BC36954FB22545152F229AA38', SyncMailboxInfo: 'True', SyncSwitched: 'False', SyncAllContent: 'False', SyncFolderContent: 'False').
9/5/2012 10:01:19 AM aeLdap:Log Error 80 Unknown error occurred (LDAP_OTHER). Cannot establish a session with an LDAP server (HostName 'SOURCEDC', ldap_open).
9/5/2012 10:01:19 AM EMWLDAP40::LDAPSearcher::Retrieve Error 5105 Cannot open LDAP on 'SOURCEDC', port '389'
9/5/2012 10:01:19 AM EMWLDAP40::LDAPOperations::GetRootDSEInfo Error 5111 Error occured during retrieve info from RootDSE (RootDSE).
9/5/2012 10:01:19 AM CMBMConn::Session Error -2147215278 Cannot create MAPI Session object."
Calendar agents require access to both source and target Exchange servers and domain controllers.
The ping from agent host to 'SOURCEDC' failed.
Resolve name resolution on the agent host. Adding 'SOURCEDC' to the hosts file resolved the issue.