From owner-freebsd-questions@FreeBSD.ORG Mon Feb 16 09:53:39 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DE2A616A4CE for ; Mon, 16 Feb 2004 09:53:39 -0800 (PST) Received: from mta4.rcsntx.swbell.net (mta4.rcsntx.swbell.net [151.164.30.28]) by mx1.FreeBSD.org (Postfix) with ESMTP id B722943D1D for ; Mon, 16 Feb 2004 09:53:39 -0800 (PST) (envelope-from david.brinegar@acm.org) Received: from hush.corte.roble (adsl-64-161-25-137.dsl.sntc01.pacbell.net [64.161.25.137])i1GHrca3002641 for ; Mon, 16 Feb 2004 11:53:38 -0600 (CST) Received: by hush.corte.roble (Postfix, from userid 1000) id AB2AE374; Mon, 16 Feb 2004 09:53:40 -0800 (PST) Date: Mon, 16 Feb 2004 09:53:40 -0800 From: David Brinegar To: freebsd-questions@freebsd.org Message-ID: <20040216175340.GB14573@mail.brinegar-computing.com> References: <20040216091316.98506.qmail@web9602.mail.yahoo.com> <20040216093332.GA85516@xor.obsecurity.org> <20040216043701.C95778@admin1.mdc.net> <20040216101801.GB58487@grover.logicsquad.net> <20040216055328.W1531@admin1.mdc.net> <20040216121927.GO58487@grover.logicsquad.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040216121927.GO58487@grover.logicsquad.net> User-Agent: Mutt/1.4.1i Subject: Re: spam removal X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Feb 2004 17:53:40 -0000 Paul A. Hoadley wrote: > Let's imagine that Charles gets a bounce notification, but it doesn't > reach his threshold for doing anything more about it. Bob loses > legitimate mail. Bounce messages are typically not good enough to avoid this. The other day a client tried to send an e-mail that exceeded my ISP's limit and was told something like "mailbox is full" and had no idea that the mailbox was empty but for their gigantic message. Thank you qmail. Funny enough, they just assumed it was another of those DNS blocks and had nothing to do with my mailbox, so I suppose they've grown weary of these DNS blocked messages. Another example is prodigy.net, which is spread out all over AOL and SBC DSL and who knows what else. When you send a message as a DSL customer, it goes out of a random mailer on prodigy.net including some that are DNS blocked by computers using the same network. So when you send mail to other prodigy.net users, you randomly get DNS blocked. The error message says that some.prodigy.net rejected a message from another.prodigy.net, which is mystifying to say the least. So it is definitely over-used and misused. But I must admit that limited DNS blocking is great. Like blocking dial-up users who send directly instead of out the ISP's smtp server. Spammers are sending a lot of traffic from cracked dial-up computers, and this method chops that off cleanly. The trick is to make sure that the rejection message is helpful to someone who might bother to read it. A bunch of numbers and "hello my name is qmail" doesn't cut it. -- David Brinegar http://brinegar-computing.com