[comp.mail.sendmail] addressing priority

bruce@balilly.UUCP (Bruce Lilly) (01/18/91)

In article <2505@sapwdf.UUCP> Bill Wohler <wohler@sap-ag.de> writes:
>
>  i was under the impression that internet addressing took priority.
>  that is, an address like hosta!user@hostb would be sent to hostb
>  first.

That's correct for Internet sites, however sites connected only via uucp
to other sites using very old uucp software may operate differently.

>  the sendmail.cf's around here send such a message to hosta first.
>
>  is this correct?  if not, what section of sendmail.cf should i look
>  at.

Depends on what your site is trying to do (see above). Ruleset 0
determines which mailer, site, and user address are used for delivery.

>    if so, how can i modify the address so that the message goes to
>  hostb first?  

Given the way you say your .cf's work, hostb!hosta!user should do the
trick.

>    what is the current rfc number that covers this
>  issue?

RFC 1123 covers this issue and refers to several older, but still valid
RFC's (e.g. RFC 822).

Note: there may be some strong opinions about some of the above,
especially @ vs ! precedence. Flames should be sent either to Baghdad or
to /dev/null.
--
	Bruce Lilly		blilly!balilly!bruce@sonyd1.Broadcast.Sony.COM

dbfunk@icaen.uiowa.edu (David B Funk) (01/19/91)

In article <2505@sapwdf.UUCP> Bill Wohler <wohler@sap-ag.de> writes:
>
>  i was under the impression that internet addressing took priority.
>  that is, an address like hosta!user@hostb would be sent to hostb
>  first.
>  the sendmail.cf's around here send such a message to hosta first.
>  is this correct?  if not, what section of sendmail.cf should i look
>  at.  if so, how can i modify the address so that the message goes to
>  hostb first?  what is the current rfc number that covers this
>  issue?
>

  There are 2 general formats of e-mail addresses, internet & UUCP.
(the less said about Berknet & route addrs, the better 8-)
Assuming that you have mail that needs to be routed through 1 system
(say hosta) to be delivered to a user on a second system (say hostb)
then the addresses would look like:

Internet:   user%hostb@hosta

UUCP:       hosta!hostb!user

Both of these formats can be extended to arbitrarily long paths in an
unambiguous manner ( user%hostc%hostb@hosta & hosta!hostb!hostc!user ).
  As both are unambiguous valid address, it is possible to create rule
sets that will automatically convert from one form to the other.
Ideally, a sendmail should handle both of these addresses and consider
them equivalent.

  The address example from the posting "hosta!user@hostb" is a misfit
mish-mosh address that has parts of internet & UUCP combined. As the
poster found, it is ambiguous, and can be interpreted in 2 different
ways, depending upon the site conventions. This address form should be
avoided and its use discouraged.
  So in answer to the question, the address should be converted to one
of the above mentioned formats which will then force the desired
interpretation. IE  hosta!user@hostb => user%hosta@hostb should force
the interpretation of "send it to hostb for delivery to user on hosta".

Dave Funk

emv@ox.com (Ed Vielmetti) (01/20/91)

In article <1991Jan19.155744.17286@mp.cs.niu.edu> rickert@mp.cs.niu.edu (Neil Rickert) writes:

    It is not certain that these addresses are equivalent.  It might be
   more accurate to say that hosta!hostb!hostc!user is equivalent to
   user%hostc.UUCP%hostb.UUCP@hosta.UUCP, at least where the hostnames are
   unqualified.  

No, it would be just plain wrong to say that.

a!b!c!user is a perfectly valid, unambiguous, and logical uucp path;
the other thing you posted is not a legal RFC domain name (for any
RFC), nor is it ever very likely to be used by anyone sensible or
generated by any correctly configured mailer.

--Ed
emv@ox.com