On Fri, Nov 08, 2002 at 04:43:23PM -0500, David A. Bandel wrote: >-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > >On Fri, 8 Nov 2002 13:08:07 -0800 >begin Bill Campbell <[EMAIL PROTECTED]> spewed forth: > >[snip] > >> >> Nobody who has the faintest clue about e-mail believes anything in the >> From: or Reply-To: headers in spam since forging them is trivial. > >A properly configured sendmail server will not allow just anyone to >rewrite the From: header. Your mailer can change the Return-Path:, but >not the From:. Only defined trusted users can do this. So either covad's >mail server is misconfigured (everyone is trusted), or they're in on this. > At the very least, the spam originated with them and they know who it is.
Very few MTAs check the From: headers in the message. Better ones will check the SMTP ``MAIL FROM:'', at least to verify that there are ``MX'' or ``A'' records for the domain part of the address. A few cable companies refuse mail from their customers with anything in the From: or Reply-To: headers that isn't in the cable company's domain (which is why most of our customers on cable use uucp over tcp through our servers, and don't use their provider's mail system for anything). A huge portion of spam these days comes through misconfigured proxies or open relays, or from huge spam factories in Florida where the industrial strength spammers have bought their own ISPs. In the case of the proxies and open relays, do you expect them to get sendmail configured properly if they can't close the relays? About seven years ago we were mailbombed by a student at Georgia Tech, filling the hard drives on two of our servers, and we spent an afternoon educating a couple of local FBI agents on the ins and outs of Internet mail. They spent the next year making life difficult for the student, but more as an educational exercise than anything else. The agents said that they normally don't pursue anything causing less than $5,000 damage. Bill -- INTERNET: [EMAIL PROTECTED] Bill Campbell; Celestial Software LLC UUCP: camco!bill PO Box 820; 6641 E. Mercer Way FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676 URL: http://www.celestial.com/ Government is the great fiction, through which everbody endeavors to live at the expense of everybody else. -- Frederic Bastiat _______________________________________________ Linux-users mailing list [EMAIL PROTECTED] Unsubscribe/Suspend/Etc -> http://www.linux-sxs.org/mailman/listinfo/linux-users
