Thank uxbod for your reply,
It has helped me configuring the options to connect to the server, however I was wondering if I need to install everything specified in it just to authenticate users based on their email accounts.
I'm currently trying to authenticate only using the Zimbra OpenLdap and I am getting the following error:
2008-11-04T12:44:48-05:00 DEBUG (7): Ldap: 1: host=9.0.1.2,useSsl=0,username=CN=config,password= *****,bindRequiresDn=true,baseDn=DC=domain,DC=com, accountDomainName=domain.com,accountDomainNameShor t=DOMAIN,accountCanonicalForm=4
2008-11-04T12:44:48-05:00 DEBUG (7): Ldap: 2: jsmith@domain.com authentication failed: 0x20: No such object: (&(objectClass=posixAccount)(uid=jsmith))
2008-11-04T12:44:48-05:00 DEBUG (7):
Update: Zimbra is running on a linux CentOs 5 server.