For Zimbra Web Client, a Local Folders folder is created on Zimbra Desktop. Messages put into the Local Folders folder are saved to your computer and deleted from the server.

To archive Zimbra messages, create folders within Local Folders and move messages to these folders.  You can also drag an entire personal folder to the Local Folder. The next time you sync, the messages you moved to the Local Folders folder are removed from the server. Messages in the Local Folders folder are not available when you directly log in to your Zimbra account.

Note: When you delete files from the Local Folder, they are not put in the Trash folder, but are
immediately deleted.