From owner-freebsd-chat Thu Nov 27 22:06:24 1997 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA22849 for chat-outgoing; Thu, 27 Nov 1997 22:06:24 -0800 (PST) (envelope-from owner-freebsd-chat@FreeBSD.ORG) Received: from detlev.UUCP (ppp42.wcc.net [208.6.232.42]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA22815; Thu, 27 Nov 1997 22:05:56 -0800 (PST) (envelope-from detlev!joelh) Received: (from joelh@localhost) by detlev.UUCP (8.8.7/8.8.7) id AAA00737; Fri, 28 Nov 1997 00:04:04 -0600 (CST) (envelope-from joelh) Date: Fri, 28 Nov 1997 00:04:04 -0600 (CST) Message-Id: <199711280604.AAA00737@detlev.UUCP> To: jkh@time.cdrom.com CC: grog@lemis.com, jmb@FreeBSD.ORG, chat@hub.freebsd.org In-reply-to: <18154.880528164@time.cdrom.com> (jkh@time.cdrom.com) Subject: Re: major push by spammers? From: Joel Ray Holveck Reply-to: joelh@gnu.org References: <18154.880528164@time.cdrom.com> Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > 2 ways: The first, if reverse DNS lookup fails, accounts for about 90% > of the rejects. When I first started doing this, I worried that > perhaps I was rejecting some legit emails so for the first couple of > weeks I'd do one day on, one day off. In 14 days worth of testing, I > got one "legitimate" message (though it was unanswerable due to said > misconfiguration, so I could have done without it :) and many many > hundreds of spams on the days that I had reverse DNS checking > disabled. Needless to say, I can't even imagine not having it on now. Now tell me, how does the reverse DNS lookup work? Does it perform a reverse DNS against the IP source vs. the line sent in EHLO, or what? -- Joel Ray Holveck - joelh@gnu.org - http://www.wp.com/piquan Fourth law of programming: Anything that can go wrong wi sendmail: segmentation violation - core dumped