function plt_hide_atec_smtp_mail_menus() {
//Hide the "atec-systems" menu.
remove_menu_page('atec_group');
//Hide the "atec-systems → Dashboard" menu.
remove_submenu_page('atec_group', 'atec_group');
//Hide the "atec-systems → SMTP Mail" menu.
remove_submenu_page('atec_group', 'atec_wpsm');
}
add_action('admin_menu', 'plt_hide_atec_smtp_mail_menus', 11);