From owner-freebsd-net Tue Oct 16 14: 4:14 2001 Delivered-To: freebsd-net@freebsd.org Received: from fepZ.post.tele.dk (fepz.post.tele.dk [195.41.46.133]) by hub.freebsd.org (Postfix) with ESMTP id 6A4C437B405 for ; Tue, 16 Oct 2001 14:04:11 -0700 (PDT) Received: from arnold.neland.dk ([62.243.124.200]) by fepZ.post.tele.dk (InterMail vM.4.01.03.23 201-229-121-123-20010418) with ESMTP id <20011016210407.PJMG2863.fepZ.post.tele.dk@arnold.neland.dk>; Tue, 16 Oct 2001 23:04:07 +0200 Received: from gina ([192.168.5.109]) by arnold.neland.dk (8.11.6/8.11.6) with SMTP id f9GL4cq01386; Tue, 16 Oct 2001 23:04:39 +0200 (CEST) (envelope-from leifn@neland.dk) Message-ID: <005c01c15686$13eead60$6d05a8c0@neland.dk> From: "Leif Neland" To: "Matthew Emmerton" , "Graham Dunn" Cc: References: <01cc01c155d1$2547e8c0$1200a8c0@gsicomp.on.ca> <20011015200352.A29974@inscriber.com> <030701c155dc$e152f180$1200a8c0@gsicomp.on.ca> Subject: Re: Strange situation with NAT and sendmail [ FIXED ] Date: Tue, 16 Oct 2001 23:03:58 +0200 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > > I did a tcpdump on the NAT box on network A - it never records any incoming > packets destined for port 25 whatsoever. However, it does record incoming > packets for port 81 (the administration web server for the mail server.) > > Therein lies the answer. It would appear that the ISP providing me > residential broadband has now started filtering outbound access to port 25 - > you can only send via their mail server. This is why I can't connect to the > mail server on the remote network, but everything else works fine. Do you mean access to your port 25 from the outside is blocked? In that case, just put your ISP's mailservers as secondary MX, then you will get your mail from that server. It is done to avoid dumb people creating open relays, because they can't configure their mailservers properly. If you mean access from your network to port 25 outside, that is done to have control of YOU not spamming. Just your ISP's mailserver as smarthost. In general, it is done in the best interest of the rest of the internet. If you can not live with that, perhaps you can get full access for a fee... Or perhaps not, if your connection is classified as residential, then you shouldn't have need for that, they believe... Leif To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message