function plt_hide_sendmachine_menus() {
//Hide "Sendmachine".
remove_menu_page('sendmachine');
//Hide "Sendmachine → Dashboard".
remove_submenu_page('sendmachine', 'sendmachine');
//Hide "Sendmachine → Feed".
remove_submenu_page('sendmachine', 'sendmachine_feed');
//Hide "Sendmachine → Settings".
remove_submenu_page('sendmachine', 'sendmachine_settings');
}
add_action('admin_menu', 'plt_hide_sendmachine_menus', 11);