Regarding the subject matter I note that I set the email quota for a client group to 3 mb, but in reality this value is ignored by ISPConfig. It only works if it is set to email and panel boxes individually, not as a customer panel disk quota general. The following screens that recall the settings: WORK NOT WORK Thank you so much for the support.
The settings on the client limits tab are applied when the client alters email user, so a client can not enter more then 3mb for all his mailboxes. So these limits are no group quota like you name it, they are the limit for quotas of the client.