Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!ames!bionet!turbo.bio.net!lear From: lear@turbo.bio.net (Eliot) Newsgroups: comp.mail.misc Subject: Re: Which headers may Sendmail re-write? Message-ID: Date: 31 Dec 90 22:20:09 GMT References: <27763742.4907@tct.uucp> <277A64CD.4C4B@tct.uucp> <1990Dec31.190906.328@chinet.chi.il.us> Organization: GenBank Computing Resource for Mol. Biology Lines: 30 les@chinet.chi.il.us (Leslie Mikesell) writes: >Philosophically, I don't like any form of rerouting other than to the >specified "next-hop" host, but realistically it is probably better >to re-route to the right-most FQDN. Yes, this should be reasonable, but how you look for an FQDN is very important, as one of the problems you list in your article that I reference is that other things can have dots in their names. In general, I short circuit by looking for recognized top level domains. Basically, I have a class that defines them all. Admittedly, it slows down my mailer just a bitk, and if someone else uses a system that looks and smells like ours but isn't, then a message could conceivably be lost. There is one failure that has occurred in the past when one short circuits, that is really caused by people using forwarders without their knowledge or permission. Example: From: lear@turbo.bio.net (some random internet site) To: 2030@x001.z76.fidonet.org (some fidonet site) If an intermediate site translates 2030@x001.z76.fidonet.org to ucbvax!uunet!rutgers!apple!well!x001.z76.fidonet.org!2030, unless prior arrangements have been made, it is quite likely that the address will be rewritten back to 2030@x001.z76.fidonet.org. A mailer loop. -- Eliot Lear [lear@turbo.bio.net]