Path: utzoo!utgpu!attcan!uunet!husc6!ukma!cwjcc!hal!ane
From: ane@hal.UUCP (Aydin "Bif" Edguer)
Newsgroups: comp.mail.uucp
Subject: Re: active rerouting
Message-ID: <290@hal.UUCP>
Date: 29 Sep 88 12:17:54 GMT
References: <4740@b-tech.UUCP> <4747@b-tech.UUCP> <4748@b-tech.UUCP> <6581@chinet.UUCP> <2105@edsews.EDS.COM> <12604@ncoast.UUCP>
Reply-To: ane@hal.cwru.edu (Aydin "Bif" Edguer)
Organization: Biometry Computing Facility
Lines: 58

In article <12604@ncoast.UUCP> allbery@ncoast.UUCP (Brandon S. Allbery) writes:
 >As quoted from <2105@edsews.EDS.COM> by roberts@edsews.EDS.COM (Ted Roberts):
 >+---------------
 >| In article <6581@chinet.UUCP>, les@chinet.UUCP (Leslie Mikesell) writes:
 >| > 
 >| > Suppose
 >| > you want siteC to route  siteA!siteB!siteC!domain.dom!user or
 >| > siteA!siteB!siteC!user@domain.dom.
 >| 
 >| These are not the same thing.  The first route would send to siteA, then
 >| siteB, then siteC and siteC would route to user@domain.dom which they
 >| would know how to do since they know how to resolve domain addresses
 >| (you hope:-).  The second would attempt to send to domain.dom, then to
 >| siteA, then to siteB, then to site C, then to user.  This is because the
 >| "@" syntax takes precedence over the "!" syntax.
 >+---------------
 >WRONG!!!  "@" and "!" are used by different networks -- there is NO defined
 >precedence between them!  (You're comparing apples to oranges.)  UUCP sites
 >give "!" precedence, Internet domain mailers give "@" precedence.
BZZZ!  Wrong WRONG :-)
All internet sites should give "@" precedence.
All RFC976 compliant UUCP sites should give "@" precedence.
All lowlife, noncompliant UUCP sites give ! precedence :-)
Here is the relevant quote from RFC976:
	"UUCP Mail Interchange Format Standard
	 2.1  Hybrid Addresses
	   In conformance with RFC-822 and the AT&T Message Transfer
	   Architecture, we recommand that any host that accepts hybrid
	   addresses apply the (a!b)@c.d interpretation."
	 5.  Summary
	   The originating site should ensure that the addresses conform to
	   RFC-822, since no requirement is placed on forwarding sites or
	   gateways to transform addresses into legal RFC-822 format.

 > On ncoast (a UUCP system) "!" has precedence.  Our neighbor "hal" gives "@"
 > precedence because they are on the Internet.  This can be quite useful; if I
 > want to send mail across the Internet I can mail to hal!foo@bar.COM, thus
 > overriding the UUCP route (which may well be slower) that smail would give
 > me from a straight "foo@bar.COM".
Yes.  But the proper way to do this is to send to hal!bar.COM!foo.
WHENEVER POSSIBLE, use non-ambiguous paths (only "!"'s or "@"'s, not both).
I promise to correct the problem if it does not attempt delivery to foo@bar.com
when given the path hal!bar.com!foo. (note: I make no guarantees it will
actually get there)
I am not yet a class 3 site (I do not currently use the pathalias database)
but I do try to conform to the rest of the RFC976 standard.

 > Things get even more interesting when you try to apply your rules to a
 > DecNet network or to the Bitnet as well (on Decnet, does "::" have
 > precedence above or below "@"?  How about "!"?  Does Decnet even *care* what
 > the relative precedence of "!" and "@" is?)
If the site is DECnet \(tm ONLY then it is welcome to do anything it wants
(including eating fudge brownies whenever it sees an "@") but if it is on
the Internet, then it is supposed to be RFC822 compliant and RFC822 says
that "@" has precedence!  The information to the left of the "@" is local
information.

Aydin Edguer					Case Western Reserve University