The FTP Mirroring tab of the server settings is used to have the Q++Studio server send a copy of your nightly backups to the Q++Studio technical support. This ensures that a backup is available, even in case of a catastrophe (theft of all workstations, fire, ...). If your site has a dependable and permanent internet connection, then we strongly urge you to turn this option on.
When in doubt, you should use the Passive Mode.
Added the Override max. size of backup files option of using a specific maximum size for the nightly automated backup files for some clients whose internet connection does not support larger FTP uploads (the default is 50 MB).
See also: other server settings.