Class of Service (COS) is a Zimbra-specific object that determines what default attributes users' accounts have and what features are added or denied. The COS controls mailbox quotas, message lifetime, password restrictions, attachment blocking, and server pool.
A default COS is created when Zimbra is installed. You can modify the default COS and create new ones. A COS is a global object and is not restricted to a particular domain or set of domains.
COS is used to group accounts and define the feature levels for those accounts. Each account is assigned a COS. You could, for example, create an Executive COS which is configured to enable all features, have unlimited mailbox quotas and never purges messages and create another General-Employee COS which enables only the mail feature, sets the mailbox quota and purges messages every 60 days. Grouping accounts to a specific COS lets you update or change account features in block. When the COS is changed all accounts assigned to the COS are changed.
If a COS is not explicitly set for a new account, or if the COS assigned to the user no longer exists, the Zimbra default COS is automatically assigned.
A COS setting includes the following:
General Information page showing the COS display name and a one line description that is displayed in the COS content pane.
Features page listing all the features, and whether they are enabled or not.
Preferences page showing what mail-view preferences are enabled and you can select the language that displays in the Zimbra Web Client for the accounts in this COS.
Themes page showing the default theme, installed themes, and available themes. See Defining Theme for the Zimbra Web Client UI.
Zimlets page showing a list of Zimlets that are installed and available for the user interface. See Adding Zimlets to COS and Accounts.
Server Pool page listing the mailbox hosts that are available to be assigned a new mailbox. See Assigning Accounts to Different Servers.
Mobile Access page to enable mobile sync and configure mobile device settings. You can also set the S/MIME settings or the mobile device from this page.
Advanced page showing quotas, password constraints, session length, and message lifetimes, and attachment blocking use. See Account Advanced Features.
Retention Policy page to configure COS retention policies. Retention and deletion policies configured as a global setting are displayed on this page if retention policies are not set in the COS. See Configure Message Retention and Disposal Policies.
Archiving. Enable the archiving feature and change the date format and the file naming template for archive accounts.
ACL page displays a list of Access Control Entries (ACE) granted ON the target you are viewing. You can add additional rights and edit or delete an ACE that is granted to this target.
Even though a COS is assigned to an account, the COS attributes can be overridden by:
Changes end users make to their mailbox options
Global settings set to reject attachments
Individual accounts settings changed to override specific COS attributes
Important: Mailbox features are enabled or restricted for Zimbra Web Client users. IMAP and POP client users may not have the restrictions that are configured in their COS.
-------------------------------------------------------------------------------------------------------
Copyright @ 2005-2017 Synacor, Inc. All rights reserved. "Zimbra" is a registered trademark of Synacor, Inc.