i've always thought this would be a neat idea. finally someone implemented it :). postfix lang though. maybe sendmail will eventually get this.
On Wednesday 26 March 2003 10:53 pm, Orlando Andico wrote: > hello all, > > we're currently running Ralf Hildebrandt's "reject_unverified_sender" > Postfix feature at MosCom, and initial results look interesting. > > Quick overview: "reject_unverified_sender" is a neat feature. When smtpd > receives the "Mail from:" right after HELO/EHLO, it queries its database > as to whether the sender email is deliverable. There is an asynchronous > process which probes the remote sender to update the database. > > e.g. spammers are fond of using forged email addresses, e.g. > "[EMAIL PROTECTED]" etc. which change for every spam sent. > Traditionally this is hard to block. However Postfix will query > Hotmail.com as to whether such an account really exists. If it does not -- > the mail is rejected. > > Postfix also caches "known good" sender e-mails, so for legal senders, > there is virtually no performance slowdown. This is a very good feature > which I think everyone should test. > > In conjunction with an RBL (e.g. orbs, monkeys, spamhaus) this feature of > Postfix ought to stop 95%+ of all spam. > > You can get this feature in the latest snapshot of Postfix. The current > 2.0.7 release doe *NOT* have it. > > > --- > Orlando Andico <[EMAIL PROTECTED]> > Mosaic Communications, Inc. > > _ > Philippine Linux Users Group. Web site and archives at > http://plug.linux.org.ph To leave: send "unsubscribe" in the body to > [EMAIL PROTECTED] > > Fully Searchable Archives With Friendly Web Interface at > http://marc.free.net.ph > > To subscribe to the Linux Newbies' List: send "subscribe" in the body to > [EMAIL PROTECTED] -- Gerald Timothy Quimpo tiger*quimpo*org gquimpo*sni-inc.com tiger*sni*ph Public Key: "gpg --keyserver pgp.mit.edu --recv-keys 672F4C78" Lack of money is the root of all evil. George Bernard Shaw _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] Fully Searchable Archives With Friendly Web Interface at http://marc.free.net.ph To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
