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From: rickert@mp.cs.niu.edu (Neil Rickert)
Newsgroups: comp.mail.sendmail
Subject: Re: problem with uucp-originated mail
Message-ID: <1990Dec6.234758.28937@mp.cs.niu.edu>
Date: 6 Dec 90 23:47:58 GMT
References: <9812@darkstar.ucsc.edu>
Organization: Northern Illinois University
Lines: 53

In article <9812@darkstar.ucsc.edu> haynes@ucscc.UCSC.EDU.UUCP (Jim Haynes) writes:
>Just one of my uucp clients is having a problem.  With mail sent to
>me from user at that host, the return address is getting rewritten
>to    somewhere!user@host.uucp  He's using some kind of Macintosh
>software that is supposed to emulate uucp.  Anybody know where
>"somewhere" is coming from, and how to get rid of it?

 Most likely the 'somewhere' is coming from your own 'rmail'.

 Do:  strings rmail | grep somewhere

as a quick check.

 'rmail' is assuming uucp style addressing.  It looks at the 'From '
line at the beginning of the incoming message to determine the sender.
It expects something like:

From host2!host3!user  (date and time) remote from host1

 or will usually accept:

From host1!host2!host3!user (date and time)

 To determine the sending host, it looks at everything preceeding the
first '!', or at the 'remote from' name if present.  In the absence of
either, it inserts a 'somewhere'.

 Solutions:

	Best solution - change the mac software to use 'host!user'
	or even 'host.UUCP!user' rather than 'user@host.UUCP'

	Alternate solution - get a different version of 'rmail'.  The
	version distributed with the IDA versions of sendmail, in
	the subdirectory ida/aux.  It will probably have to be run
	suid root if you don't want the mail to show up as 'From: uucp'
	or 'From: someuser' where 'someuser' happens to be the person
	who did a 'uucp' command which initiated the connection.  This
	has the disadvantage that it makes forging sender addresses
	easier if rmail is publically executable.  (I use this version of
	rmail, and run it suid root.  It is executable only by owner (root)
	or group (daemon).  Since 'uuxqt' is sgid daemon, this works for
	uucp connections, but not for local users directly invoking rmail.
	(They can probably invoke rmail via uux though, but if they are
	that clever they already know how to fake out sendmail).

 Hope this helps.

-- 
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  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115.                                  +1-815-753-6940