function plt_hide_mail_grab_menus() {
//Hide the "Mail Grab" menu.
remove_menu_page('edit.php?post_type=mlgb_email');
//Hide the "Mail Grab → All Emails" menu.
remove_submenu_page('edit.php?post_type=mlgb_email', 'edit.php?post_type=mlgb_email');
//Hide the "Mail Grab → Settings" menu.
remove_submenu_page('edit.php?post_type=mlgb_email', 'settings');
}
add_action('admin_menu', 'plt_hide_mail_grab_menus', 11);