Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!sri-spam!sri-unix!teknowledge-vaxc!dplatt From: dplatt@teknowledge-vaxc.ARPA (Dave Platt) Newsgroups: comp.mail.misc Subject: Re: Info on IDA Sendmail kit / pathalias Message-ID: <17344@teknowledge-vaxc.ARPA> Date: Mon, 28-Sep-87 12:55:38 EDT Article-I.D.: teknowle.17344 Posted: Mon Sep 28 12:55:38 1987 Date-Received: Tue, 29-Sep-87 07:10:41 EDT References: <20962@ucbvax.BERKELEY.EDU> <1692@umix.cc.umich.edu> Organization: Teknowledge, Inc., Palo Alto CA Lines: 25 In-reply-to: honey@umix.cc.umich.edu's message of 27 Sep 87 03:47:05 GMT Posting-Front-End: GNU Emacs 18.41.7 of Fri Aug 28 1987 on teknowledge-vaxc (berkeley-unix) In article <20962@ucbvax.BERKELEY.EDU>, writes: i suppose it's possible to make the local mailer a router that looks at the address and passes the message back to sendmail ... maybe not. Yah... I've done it, sort of. My hack (I call it "pathfinder") doesn't pass the message "back to sendmail", though; it passes the message forwards, into another incarnation of sendmail, with a new address. I use "pathfinder" to locate the "best" path from my machine (which is on the Internet) to arbitrary hosts on the UUCP net, via one of about 15 different gateway systems. Works pretty well, in practice; its biggest single drawback is that the message passes through sendmail twice, thus generating two sets of syslog entries. Second biggest drawback is that only a single gateway is selected for each message, and if that gateway's down, the message sits in the local queue until it comes back up; it's impossible to reroute the message (e.g. by changing the topology files and rebuilding the paths database) without manually removing it from the queue. A better approach would be for the addressing lookup to occur within sendmail, and for there to be several alternative paths (with costs) for each destination host. This would require more hacking with the guts of sendmail's address-rewriting rules than I'm really comfortable with, so I've deferred any such work until after the next appearance of Comet Kohoutek.