From owner-freebsd-questions@FreeBSD.ORG Thu Sep 14 03:41:35 2006 Return-Path: X-Original-To: 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 4DA1016A403 for ; Thu, 14 Sep 2006 03:41:35 +0000 (UTC) (envelope-from keramida@ceid.upatras.gr) Received: from igloo.linux.gr (igloo.linux.gr [62.1.205.36]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7371043D49 for ; Thu, 14 Sep 2006 03:41:34 +0000 (GMT) (envelope-from keramida@ceid.upatras.gr) Received: from gothmog.pc (host5.bedc.ondsl.gr [62.103.39.229]) (authenticated bits=128) by igloo.linux.gr (8.13.8/8.13.8/Debian-2) with ESMTP id k8E3eDUl020247 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Thu, 14 Sep 2006 06:40:14 +0300 Received: from gothmog.pc (gothmog [127.0.0.1]) by gothmog.pc (8.13.7/8.13.7) with ESMTP id k8E3eXfI075218; Thu, 14 Sep 2006 06:40:34 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Received: (from giorgos@localhost) by gothmog.pc (8.13.7/8.13.7/Submit) id k8E3eMhj075158; Thu, 14 Sep 2006 06:40:22 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Date: Thu, 14 Sep 2006 06:40:22 +0300 From: Giorgos Keramidas To: Matthew Seaman Message-ID: <20060914034022.GD74348@gothmog.pc> References: <45082E5C.5040503@daleco.biz> <20060913163722.GA62734@gothmog.pc> <45083857.40405@infracaninophile.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45083857.40405@infracaninophile.co.uk> X-Hellug-MailScanner: Found to be clean X-Hellug-MailScanner-SpamCheck: not spam, SpamAssassin (score=-2.785, required 5, autolearn=not spam, AWL -0.19, BAYES_00 -2.60, UNPARSEABLE_RELAY 0.00) X-Hellug-MailScanner-From: keramida@ceid.upatras.gr X-Spam-Status: No Cc: questions@freebsd.org Subject: Re: sendmail and hosts_access(5) 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, 14 Sep 2006 03:41:35 -0000 On 2006-09-13 17:56, Matthew Seaman wrote: > hosts.allow triggers special behaviour with sendmail. Unlike other > services which just close the connection immediately, with sendmail > what happens is that it will accept the connection, let the sender > attempt to send e-mail, but then respond with a 500 'permanent > failure' code. > > The reason for that is fairly simple: if a MTA gets no answer when > trying to connect to a server and deliver e-mail, then the standards > say it should requeue the message and try again for up to 5 days. The > only way to get the sending MTA to give up immediately is to issue a > SMTP 500 error code. Ah! I see now. Thanks for taking the time to write this cool, detailed explanation. Now I know one more thing about Sendmail :-)