I have parameterized in the admin--->setting--->customer--->servers (not allowed to use the system, not allowed to select smtp), But in the customer part the server menu is displayed but can not be changed. I want to delete this menu
Backend > Settings > Clients > Servers > Max. delivery servers > 0, this option will prevent clients from seeing the delivery servers tab. Also, make sure the option is set to 0 in Customer > Groups if your customers are assigned to a group.