user@[my.ip.add.ress]

[David Nugent <davidn@sdev.blaze.net.au>]

On Tue, 13 Feb 1996, Matti Aarnio wrote:

> > of the bugs in which have since been fixed bar one (that is, attempting to
> > send to the current machine via name@[x.x.x.x] still does not work without
> > applying a correction to rrouter.cf).
> 
> 	In theory, the change is rather simple -- we must add recognition
> 	of local bracketed address into that place
~
> z# router "fii@[130.232.1.11]"
> <mea.interactive@mea.utu.fi>: address: fii@[130.232.1.11]
> (((local fii@[130.232.1.11] fii default_attributes)))
> z# router "foo@[130.232.1.1]"
> <mea.interactive@mea.utu.fi>: address: foo@[130.232.1.1]
> (((smtp [130.232.1.1] foo@polaris.cc.utu.fi default_attributes)))
> 
> 	That latter form is illegal in local system -- polaris does
> 	not have mailer at all, and this form does not use MXes to
> 	find the right host..  (mailhost.utu.fi)

The problem isn't where the mail *originates*, though, but to whom
the mail is addressed (ie. the recipient). When Zmailer attempts to
deliver mail coming from outside which is addressed to user@[...]
(where ... is its own ip address), rrouter.cf still returns an smtp
target, and ends up bouncing the mail because it tries to deliver
to itself.


> -------------  $MAILSHARE/cf/rrouter.cf --------------
> .....
> 	(.*)<@\[(.)\]>(.*)
> 		# numeric internet spec
> 		if [ $(deliver "[\2]") ]; then
> 			address="\1<@>\3"
> 		else
> 			return (((smtp "[\2]" "\1@$(gethostbyaddr \2)\3" $A)))
> 		fi
> 		;;
> .....
> ------------------------------------------------------

Actually, the fix I applied is simpler than that, and does not require
fiddling with $MAILSHARE/db/localnames. I simple changed the line
which read:

           return (((smtp "[\2]" "\1@$(gethostbyaddr \2)\3" $A))) ;;

to read:

           address = "\1<@$(gethostbyaddr \2)\3" ;;

Mail which resolves to a local address seems to then get local, and
remote ip addresses get the correct target also.

Is there some other side-effect of doing this that I've missed? When
I first applied it, I tested it quite extensively since I'm naturally
suspicious of such a simple fix. :-)


> > FWIW, I just did some testing later with sendmail 8.6.12, and it does show
> > the correct MX target. Perhaps that's what I'm remembering.
> 
> 	sendmail is monolithic, and there seeing the difference of
> 	routeing phase, and delivery phase is a bit difficult..

Understandably. I honestly can't imagine what would ever convince
me to go back to using sendmail...

--
David Nugent: davidn@blaze.net.au, davidn@unique.blaze.net.au
Unix/Linux/DOS/Win/Os2 Microsystem Technical Support [FOR HIRE!]
http://www.blaze.net.au/~davidn