 i guess mua level filtering is just a fallback for people who don t have NUMBER a burning all consuming hatred of junk mail NUMBER root access to all mail servers they rely on and NUMBER the ability and inclination to install an mta with every bell and whistle tweaked to keep out junk mail sure but for most people changing their company s or isp s server requires years of lobbying while they have total and immediate control over their own mua that said i agree that we should offer a good solution to postmasters and i trust that your ideas are right on the mark guido van rossum home page URL 