Problems with relaying email...

[Don Rainwater]

	I'm having some problems with mail from my Ultrix 4.1 system.
Apparently, the headers aren't coming out quite right.  The "real" From:
header seems to be okay, since it comes out as username at ucunix.san.uc.edu
(as it should).  However, up above this in the headers is another line
that contains username at ucunix.  The name of this header line is called
either From or Return-path:, depending on the receiving machine.  When
it's a Return-path line, the address is enclosed in <>.

	For reasons of alias substitution, all mail from this Ultrix
system is forwarded (using a default relay definition in sendmail) to a
VMS system running PMDF, which then delivers the message to its
destination.  So mail travels from point A to point C via point B.

	The big problem is this:  Replying to one of these mail messages
from a machine that calls this user at simple-hostname construct a From
line is unsuccessful, since it tries to use this information instead of
the real (correct) From: line a few lines down.  There is no problem on
systems that treat this information (correctly?) as a Return-path: line,
since these systems use the real From: line instead.

	Anyone have any suggestions?  Is this a sendmail problem, a PMDF
problem, or something entirely different?  Thanks for any information.