From owner-freebsd-isp Thu Jul 1 4:39:34 1999 Delivered-To: freebsd-isp@freebsd.org Received: from hartley.mintel.co.uk (hartley.mintel.co.uk [194.217.87.65]) by hub.freebsd.org (Postfix) with ESMTP id BF5BF155E9 for ; Thu, 1 Jul 1999 04:39:31 -0700 (PDT) (envelope-from jason.thomson@mintel.co.uk) Received: from mintel.co.uk ([10.0.0.233]) by hartley.mintel.co.uk (8.9.2/8.9.2) with ESMTP id MAA03990 for ; Thu, 1 Jul 1999 12:30:51 +0100 (BST) Message-ID: <377B53F8.34DE5461@mintel.co.uk> Date: Thu, 01 Jul 1999 12:41:44 +0100 From: Jason Thomson X-Mailer: Mozilla 4.51 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: freebsd-isp@freebsd.org Subject: Sendmail 8.9.x check_mail anti-spam rule broken? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org As I understood the sendmail anti-spam rules, they are supposed to reject Sender addresses whose domain part does not _resolve_. I was under the impression that meant the domain had to have either MX or A or CNAME records. However, it would appear that the domain must have an A record. Or mail is rejected with: reject=451 <>... Sender domain must resolve For example, some.one@btinternet.com gets rejected. But btinternet.com has perfectly valid MX records. BT Internet is probably one of the UK's biggest ISPs. Can someone confirm that this is the expected behaviour (and I haven't got a broken config) and that this behaviour is correct (and not a bug). If by _resolve_, this means that a domain must have an A record, then maybe I need to add A records for all the domains that I maintain, and remove this anti-spam rule from my sendmail.cf file. (Because I might want to be able to receive mail from companies like British Telecom, MCI Worldcom etc. :-). However, this it doesn't seem quite right that a domain should require an A record. (I notice that freebsd.org does have an A record). Also, whilst our server rejected one legitimate message, that same rule has rejected several spams already today. Thanks for any pointers and info. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message