Folders can be used to store your mail messages. You can move items from one folder to another by dragging and dropping or by clicking Move from the right-click button on the mouse.
Two types of folder exist:
System folders. System folders cannot be moved, renamed, or deleted. Examples include your Inbox, Sent, and Trash folders.
User-defined folders. You can create folders to organize your mail. Folders you create are displayed in the Folders list in the Overview Pane. Top level folder names must be unique. The name cannot be the same as any other top-level folder in your Zimbra mail, calendar, or address book folders.