From owner-freebsd-questions@FreeBSD.ORG Thu Jun 2 11:54:44 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org 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 0ED9D16A41C for ; Thu, 2 Jun 2005 11:54:44 +0000 (GMT) (envelope-from bsilver@chrononomicon.com) Received: from trans-warp.net (hyperion.trans-warp.net [216.37.208.37]) by mx1.FreeBSD.org (Postfix) with ESMTP id A1D5543D1F for ; Thu, 2 Jun 2005 11:54:43 +0000 (GMT) (envelope-from bsilver@chrononomicon.com) Received: from [127.0.0.1] (unverified [65.193.73.208]) by trans-warp.net (SurgeMail 2.2g3) with ESMTP id 10573881 for multiple; Thu, 02 Jun 2005 07:54:42 -0400 In-Reply-To: <20050601143415.D69453@wolf.pjkh.com> References: <0a6397740f09ea4ac7cce0b1bead3bde@chrononomicon.com> <8B6C5637-F4B3-4635-94EA-F1B8EE9D8A2F@shire.net> <429E25BB.9080006@wcborstel.nl> <20050601143415.D69453@wolf.pjkh.com> Mime-Version: 1.0 (Apple Message framework v622) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Bart Silverstrim Date: Thu, 2 Jun 2005 07:54:30 -0400 To: Philip Hallstrom X-Mailer: Apple Mail (2.622) X-Server: High Performance Mail Server - http://surgemail.com X-Authenticated-User: bsilver@chrononomicon.com Cc: Jorn Argelo , FreeBSD Mailing List , "Chad Leigh -- Shire.Net LLC" Subject: Re: postgrey question X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jun 2005 11:54:44 -0000 On Jun 1, 2005, at 5:35 PM, Philip Hallstrom wrote: > [description of postgrey snipped] > >> The main advantage of this is that spammers and viruses have massive >> amount of email lists and just try to send it to as many people as >> possible. They are not going to wait and try to send the e-mail >> again, thus you effectively block many amount of spam and virus >> e-mail before it's even being processed by amavis / clamav / >> spamassasin, saving up system resources. > > This is also the problem with greylisting... some services only > attempt to send the email once and if it fails, give up completely. I > don't remember if postgrey comes with a whitelist of IP addresses or > not, but I do remember seeing a list that included things such as > Southwest Airlines ticket confirmations and some amazon stuff. > > Anyway, that's something to watch out for if it's relevant for you... I'd guess those are broken email systems that I wouldn't WANT email from, personally. I mean...what happens if you get something from those people and your mail server goes down for an hour, or is unable to accept mail for a window of time? From the remote's viewpoint, greylisting should just be another way of saying it needs to try again in the next interval. If people keep accepting broken implementation as the status quo, we're going to keep getting people who leave broken implementations in place.