From owner-freebsd-isp Wed Apr 28 9:55:31 1999 Delivered-To: freebsd-isp@freebsd.org Received: from carme.eclipse.net.uk (carme.eclipse.net.uk [195.188.32.33]) by hub.freebsd.org (Postfix) with ESMTP id 4E9B31522A for ; Wed, 28 Apr 1999 09:55:27 -0700 (PDT) (envelope-from stuart@eclipse.net.uk) Received: from eclipse.net.uk (elara.eclipse.net.uk [195.188.32.31]) by carme.eclipse.net.uk (8.9.3/8.9.3) with ESMTP id RAA28454; Wed, 28 Apr 1999 17:55:18 +0100 (BST) Message-ID: <37273DE7.14D1BE87@eclipse.net.uk> Date: Wed, 28 Apr 1999 17:57:11 +0100 From: Stuart Henderson Organization: Eclipse Networking Ltd. X-Mailer: Mozilla 4.51 [en] (WinNT; U) X-Accept-Language: en-GB MIME-Version: 1.0 To: Veaceslav Revutchi Cc: "W. Reilly Cooley" , freebsd-isp@FreeBSD.ORG Subject: Re: please advice how to solve a spam problem References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > The "X-Sender-IP" is a great idea. Is this a sendmail feature? You would have to add it in to your webmail system, sendmail won't know the IP address of the web browser that sent the message. There is already provision for this in IMP (see http://horde.org/). Trouble is, it's fundamentally flawed. You can't tell whether that was a real address or whether it was because someone is connecting through an open proxy (in which case you might be able to use headers added by the proxy for better tracking), or an obfuscating proxy (for example anonymizer or a crowds proxy), or even someone who left a personal proxy (wingate, webwasher, or whatever) open to public use. If you rely on that you could well put the blame onto someone who is innocent. (Of course some proxies would even let you connect to a mail server directly and hide your address, or you could be telnetted in through a chain of shell accounts, etc... Basically: if someone really doesn't want to be tracked you will have a very difficult job to find them). Cheers Stuart To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message