You get to the Admin UI by using a web browser with the follow format address: https://fqdn.yourserver.com:7071 - you login with the Admin (usernname) and the password. If you don't know the password you should change it with the command in this article (you should change it anyway). When you login to the Admin UI you can do most of the Administration from there, if you want to use the command line then I'd suggest you read the Admin Guide, click on the "Help Desk" in the top-right of the Admin UI for the Documentation page.
Originally Posted by xlr8nut
You should put the following information in your forum profile and I'd suggest as a matter of urgency you upgrade to a more recent release of Zimbra (there have been some security updates to the product).
Version: Release 4.5.4_GA_763.RHEL4_20070323121238 RHEL4 NETWORK edition