Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rutgers!mephisto!utkcs2!betelgeuse!moore
From: moore@betelgeuse.cs.utk.edu (Keith Moore)
Newsgroups: comp.mail.misc
Subject: Rewriting ! addresses to % addresses (was Re: Something)
Summary: don't do it
Message-ID: <1523@utkcs2.cs.utk.edu>
Date: 22 Dec 89 08:32:34 GMT
References: <33886@mips.mips.COM>
Sender: news@utkcs2.cs.utk.edu
Reply-To: moore@cs.utk.edu (Keith Moore)
Organization: CS Dept -- University of TN, Knoxville
Lines: 47

In article <33886@mips.mips.COM> koblas@mips.COM (David Koblas) writes:
>
>Currently a sendmail configuration that I have running "rewrites" 
>(changes from ! path to %@ path), delivers mail to its next hop.
>The Internet site which recives the message and then gateways it
>on to the UUCP network fails to rewrite it back into a ! path.
>
>[ By example:
>     user sends mail to: 	user@a
>     rewritten to      :	user%a%b%c%d@e

If it is intended that the mail go to domain e, and then via UUCP
to d!c!b!a!user, then your mailer should produce the envelope address
"d!c!b!a!user@e", and send the mail on to domain e for forwarding.
If 'e' functions as a UUCP gateway, then it should recognize the
local-part of the above address as a UUCP path, and forward the message
via uucp after stripping the "@e" part of the address.

>     site 'e' delivers
>       to UUCP site 'd':	user%a%b%c@d

Here, 'e' is exercising its freedom to interpret '%' specially.
However, it could have just as easily done something different,
such as attempting delivery to a local mailbox named "user%a%b%c".

>     site 'c' recieves :        user%a%b@c
>       and site 'c' is
>       unable to parse
>       a '%' path!


>]
>
>Thus my question is: since site 'e' gatewayed the mail message into
>UUCP, should they not change the %@ path into a ! path?
>

No.  Your site's mailer should not attempt to do complex routing with '%'.
If you know that a particular domain handles '%' specially, you can
use this knowledge for that domain.  But you cannot rely on the feature
being generally supported.


Keith Moore			Internet: moore@cs.utk.edu
University of Tenn. CS Dept.	BITNET: moore@utkvx
107 Ayres Hall, UT Campus	UT Decnet: utkcs::moore
Knoxville Tennessee 37996-1301	Telephone: +1 615 974 0822