Cas Server Failed Connect to Zimbra

[tr1dzul]

i has been installed cas server and zimbra..

when connect to mail server from web browser,

https://mydoamin.com

successfully redirect to

https://mydomain.com:8443/cas/login?...%2Fpreauth.jsp


but when i login from cas, he cannot login using username and password from zimbra..


and this is the error from catalina.out.



2011-10-10 08:45:55,963 INFO [org.jasig.cas.authentication.AuthenticationManager Impl] - <AuthenticationHandler: org.jasig.cas.authentication.handler.support.Simpl eTestUsernamePasswordAuthenticationHandler failed to authenticate the user which provided the following credentials: [username: admin]>
2011-10-10 08:45:55,963 INFO [com.github.inspektr.audit.support.Slf4jLoggingAudi tTrailManager] - <Audit trail record BEGIN
================================================== ===========
WHO: [username: admin]
WHAT: supplied credentials: [username: admin]
ACTION: AUTHENTICATION_FAILED
APPLICATION: CAS
WHEN: Mon Oct 10 08:45:55 WIT 2011
CLIENT IP ADDRESS: 192.168.122.1
SERVER IP ADDRESS: 192.168.122.245
================================================== ===========

>
2011-10-10 08:45:55,969 INFO [com.github.inspektr.audit.support.Slf4jLoggingAudi tTrailManager] - <Audit trail record BEGIN
================================================== ===========
WHO: [username: admin]
WHAT: error.authentication.credentials.bad
ACTION: TICKET_GRANTING_TICKET_NOT_CREATED
APPLICATION: CAS
WHEN: Mon Oct 10 08:45:55 WIT 2011
CLIENT IP ADDRESS: 192.168.122.1
SERVER IP ADDRESS: 192.168.122.245
================================================== ===========

please help me for this error.... i hope some one can fix my error