mouss escreveu: > João Miguel Neves a écrit : > >> Charles Marcus escreveu: >> >>> On 2/8/2009, João Miguel Neves (joao.ne...@intraneia.com) wrote: >>> >>> >>>> I recently enabled reject_unverified_sender in my postfix configuration, >>>> but it seems like it fails when the server against which the sender is >>>> verified uses greylisting. I've been getting log entries like (@ were >>>> replaced by _AT_): >>>> >>>> >>> You're not trying to verify ALL senders are you? This ia a really bad >>> idea, and will get you blacklisted by a lot of providers, especially if >>> you have high traffic . >>> >>> >> Yes, I was. Thanks for the heads up. I don't have high traffic, but I'm >> limiting the effect of SAV. >> > > and how do you limit it? 71.66.121.221 is listed on zen.spamhaus.org > (via cbl) and spamcop (as well as Barracuda BRBL, SORBS, ... etc). it is > also a residential IP as can be seen from the rDNS (.res.rr.com). > Right now, I'm preparing my top 10 domains used in spam and enabling SAV for those. >>> You should only perform SAV against servers that YOU control, or at >>> least have an agreement ahead of time with them. >>> >>> >> That would mean that the most useful use of SAV is negated. Or is there >> some prior arrangement that would allow me to do that to hotmail.com, >> gmail.com, yahoo.com*? >> >> I'm going to reduce the target domains, but is there a known agreement >> with MS, Google or Yahoo to use SAV against their servers? >> > > No, and it won't help you anyway. spammers can easily use a valid > address. and these domains have too many users that most addresses > you'll test are valid! (did you never see the "sorry, this account is > not available" when trying to open an account?). > Picking up some data from 4h when SAV was enabled from all users I get:
426 delivered emails 1742 rejected emails 985 rejects from sender checks from which: 302 were queued at the sender for SAV unverified results (*) 671 were queued at the sender for SAV undeliverable results Maybe is SHOULDN'T help, but seems like a LOT of spam is still coming from non-existing addresses (about 31% of the total email). (*) this is the number that scares me a bit - it can be thanks to greylisting, or possibly a loop caused by other server using SAV. I'm checking into that. Best regards, João Miguel Neves -- Intraneia http://www.intraneia.com/ Suporte a Software Livre Tradução/Localização de software e sítios web Desenvolvimento de software Ao seu serviço...