The Global Administrator manages the complete Zimbra Collaboration Suite email system. From the administration console you can:
Provision and manage end-user accounts
Create and maintain distribution lists
Manage domains and servers
Configure global settings for security, attachments, MTA, POP, IMAP
Monitor servers status and performance statistics
Create different Class of Service (COS) types that can be assigned to accounts to define features and settings
Create password policies
Manage volumes for message store and index store and configure a secondary volume for HSM
Monitor cluster services
Download migration and import tools which are used to migrate users to the Zimbra server and to import email, calendar and contact information
Schedule backup sessions and restore from backups
Some management tasks are not available from the console. Refer to the Zimbra Administration Guide for details about all other administration tasks.