Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!bionet!lear
From: lear@NET.BIO.NET (Eliot Lear)
Newsgroups: news.sysadmin
Subject: Re: Stuck with .UUCP forever?
Message-ID: <May.22.14.59.44.1989.11105@NET.BIO.NET>
Date: 22 May 89 21:59:44 GMT
References: <1728@fig.bbn.com> <3790007@eecs.nwu.edu> <3381@tank.uchicago.edu>
Organization: Natl Computer Resource for Mol. Biology
Lines: 22

Matt's message probably demands a bit of elaboration.  It isn't hard
to imagine a loop occurring if you allow non Internet sites to
forward.  Moreover, if you use the current version of sendmail, you
might get back a wonderful host unknown error message if you try to
mail to contact a forwarder through its MX, when its forwarder is
down.  {This was a real problem when NORDUNET came on line.}

For example:

I would mail to user@kre.nl.  You would see something like the
following for that host.

kre.nl	IN	MX	hp4nl.nluug.nl	110

and for hp4nl you might see something like the following:

hp4nl.nluug.nl	IN	A	192.16.184.9
hp4nl.nluug.nl	IN	MX	UUNET.UU.NET 100

If hp4nl.nluug.nl was out, sendmail would return a host unknown.
Obviously, this is a bug in sendmail, but one that should be fixed if
people are going to ``chain''.