From owner-freebsd-questions Tue Jul 28 11:29:26 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA09978 for freebsd-questions-outgoing; Tue, 28 Jul 1998 11:29:26 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from pau-amma.whistle.com (s205m64.whistle.com [207.76.205.64]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA09847 for ; Tue, 28 Jul 1998 11:28:54 -0700 (PDT) (envelope-from dhw@whistle.com) Received: (from dhw@localhost) by pau-amma.whistle.com (8.8.8/8.8.7) id LAA00814; Tue, 28 Jul 1998 11:25:46 -0700 (PDT) (envelope-from dhw) Date: Tue, 28 Jul 1998 11:25:46 -0700 (PDT) From: David Wolfskill Message-Id: <199807281825.LAA00814@pau-amma.whistle.com> To: questions@FreeBSD.ORG, sderdau@bit-net.com Subject: Re: email question. In-Reply-To: Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >Date: Tue, 28 Jul 1998 12:28:30 -0400 (EDT) >From: Stephen Derdau >Why would email sent by a user sderdau%mcl > be delivered and showing from sderdau@mcl instead of >sderdau%mcl@qualified.domain.com. Because of the (in)famous "percent hack". >Pointers in the write direction appreciated. >I know this is probably a sendmail question . Just hoping >someone with great expertise wouldn't mind answering it. OK; a partial list: pau-amma[36]% grep -B 2 -A 1 -n '%' /etc/sendmail.cf 91- 92-# operators that cannot be in local usernames (i.e., network indicators) 93:CO @ % ! 94- -- 367- 368-# delimiter (operator) characters (old $o macro) 369:O OperatorChars=.:%@!^/[]+ 370- -- 483-R$+ ! $+ $@ $>96 $2 < @ $1 .UUCP > uucp subdomains 484- 485:# if we have % signs, take the rightmost one 486:R$* % $* $1 @ $2 First make them all @s. 487:R$* @ $* @ $* $1 % $2 @ $3 Undo all but the last. 488-R$* @ $* $@ $>96 $1 < @ $2 > Insert < > and finish Or, to put it another way, the '%' is effectively replaced by '@'. It was a technique for allowing email with "foreign" addressing conventions such as old "bang-path" UUCP, or BITNET, or various other approaches to be gatewayed to & from the Internet. Ideally, it would have become an endangered species by now.... :-{ david -- David Wolfskill UNIX System Administrator dhw@whistle.com voice: (650) 577-7158 pager: (650) 371-4621 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message